Initial commitHEADmain

1 files changed, 1625 insertions, 0 deletions

diff --git a/75326-0.txt b/75326-0.txt
new file mode 100644
index 0000000..d42ad44
--- /dev/null
+++ b/75326-0.txt
@@ -0,0 +1,1625 @@
+
+*** START OF THE PROJECT GUTENBERG EBOOK 75326 ***
+
+TRANSCRIBER’S NOTE
+
+  Some minor misspellings in the text are silently corrected.
+
+  Enclosed small caps in ≈double tilde≈,
+  enclosed italics font in _underscores_,
+  bold text in =equal sign=.
+
+  The numbering of the drawings does not correspond to their marked
+  number. However, they have been left as they are, as the author has
+  entered them by hand in the drawings.
+
+  In the table on the color of the oxide layer of tempered steel in the
+  tempering section, the first column has been set without trailing
+  commas, as the author has handled this inconsistently.
+
+  The new original cover art included with this eBook is granted to the
+  public domain.
+
+
+
+
+A FEW SECRETS OF THE
+METALLURGIST
+SIMPLY TOLD
+
+
+ATLAS CRUCIBLE STEEL CO.
+PUBLISHERS
+DUNKIRK, N. Y.
+
+
+
+
+A FEW SECRETS OF THE
+METALLURGIST
+SIMPLY TOLD
+
+BY
+
+GERALD W. HINKLEY, M. E.
+
+CORNELL UNIVERSITY
+ORDNANCE ENGINEER
+AND ASSISTANT TO PRESIDENT
+ATLAS CRUCIBLE STEEL CO.
+DUNKIRK, N. Y.
+
+FIRST EDITION
+
+
+COPYRIGHTED 1918
+BY
+PRESS OF DUNKIRK PRINTING COMPANY
+
+
+
+
+PREFACE.
+
+
+This is not and is not intended to be a thoroughly complete explanation
+or discussion of the allotropic theory of iron and steel, but rather a
+brief outline of a few of the great principles of metallurgy written
+primarily for the layman. If without leading him astray from the real
+scientific understanding of the subject we have succeeded in briefly
+but satisfactorily answering the old familiar question, “Why do steels
+harden?”, we will in a large measure, have accomplished our purpose.
+
+Besides the personal observations which the writer has made from time
+to time in the metallurgical laboratory, he has availed himself freely
+of the works of many and eminent authors dealing with this subject and
+where disputable conditions have arisen in regard to certain theories,
+uses, etc., has attempted to adopt the most logical consensus of
+opinion.
+
+G. W. H.
+
+
+
+
+CONTENTS.
+
+A FEW SECRETS OF THE
+METALLURGIST
+SIMPLY TOLD.
+
+                                  Page
+  
+   INTRODUCTION                            17
+
+   CHAPTER I.
+
+   ≈A Slight Test of the Imagination≈      19
+
+   CHAPTER II.
+
+   ≈Comparison Between Conditions
+   Which Exist in the Iron and
+   Steel Family to Those Which
+   Exist with More Familiar Elements≈      22
+
+   CHAPTER III.
+
+   ≈An Experiment Performed with
+   a Piece of Pearlitic Steel≈             29
+
+   CHAPTER IV.
+
+   ≈High Speed Steel≈                      51
+
+   CHAPTER V.
+
+   ≈The General Effect of the More
+   Important Elements in Tool
+   Steels≈                                 61
+
+   ≈Carbon Steels≈                         61
+
+   ≈Alloy Steels≈                          63
+
+   ≈High Speed Steels≈                     64
+
+   ≈Elements Which Occur in all
+   Steels≈                                 66
+
+   ≈Iron≈                                  66
+
+   ≈Carbon≈                                67
+
+   ≈Manganese≈                             67
+
+   ≈Silicon≈                               68
+
+   ≈Phosphorus≈                            69
+
+   ≈Sulphur≈                               70
+
+   ≈Elements Which Have Become
+   Especially Associated with
+   Special Alloy Steels≈                   70
+
+   ≈Chromium≈                              70
+
+   ≈Tungsten≈                              72
+
+   ≈Molybdenum≈                            73
+
+   ≈Vanadium≈                              73
+
+   ≈Cobalt≈                                74
+
+   ≈Uranium, Titanium and Aluminum≈        75
+
+   ≈Impurities≈                            75
+
+   ≈Heat Treatment≈                        76
+
+   ≈Hardening≈                             77
+
+   ≈Annealing≈                             79
+
+   ≈Tempering≈                             81
+
+   ≈Conclusion≈                            84
+
+   CHAPTER VI.
+
+   ≈What Tool Steel Is Doing Towards
+   Winning the War≈                        85
+
+   APPENDIX.
+
+   ≈Analysis, Uses and Heat Treatment
+   of Various Grades of
+   Tool Steels≈                            92
+
+   ≈High Speed Steels≈                     93
+
+   ≈Die Steel for Hot Work≈                94
+
+   ≈Special Alloy Steel≈                   95
+
+   ≈Semi-High Speed Steel≈                 96
+
+   ≈Simple Carbon Tool Steel≈              97
+
+   ≈Non-Shrinking Oil Hardening
+   Steel≈                                  98
+
+   ≈Special Hot Work Alloy Steel≈          99
+
+
+
+
+A FEW SECRETS OF THE
+METALLURGIST
+SIMPLY TOLD
+
+
+INTRODUCTION.
+
+
+When as a student at a Technical College of one of our great
+Universities, I came to the study of Differential and Integral
+Calculus, I remember that I was seized with a kind of mental paralysis
+at the thought of the great unknown that lay before me. Fortunately,
+however, a little book was brought to my attention, under the
+encouraging title “Calculus Made Easy”. As a matter of fact the little
+volume did not attempt to take its readers through all the intricacies
+of the entire subject, but it did succeed in giving a certain start on
+the long journey which has to be undergone by a student of the
+Calculus. Its opening sentence was encouraging, which I have always
+remembered, and which read something as follows:
+
+“What one fool can accomplish, another fool can do, therefore take
+courage”. This same thought applies to the subject which is now before
+us.
+
+
+
+
+CHAPTER I.
+
+A SLIGHT TEST OF THE IMAGINATION.
+
+
+We live in a world in which certain conditions of the atmosphere and
+the so-called elements surrounding our daily existence, are entirely
+familiar to us. From force of habit we are likely to forget that had
+Nature, for instance, been planned under a different range of livable
+temperatures, all the familiar objects of our daily existence would
+have existed under entirely different form.
+
+For instance, if the normal temperature had been about 2700 degrees
+Fahrenheit instead of about 60 degrees Fahrenheit, and we had been
+constructed so that we could comfortably endure that degree of
+temperature, we could have gone sailing on a sea of molten iron, in
+boats built of plumbago crucibles, and oars made of silica brick. Under
+these delightful conditions we could place frozen lumps of our sea of
+iron in our ice boxes for refrigeration. Flat irons and stove lids
+would therefore have been the product of the ice man. The water with
+which we are now familiar, of course, could not exist in its liquid
+form, or even as steam, but instead as a highly gaseous state, which we
+would probably have been called upon to breathe. Certain other
+substances with which we are perfectly familiar in our daily life, such
+as the common stick sulphur, for instance, would exist in an entirely
+different =physical= state, although their =chemical= properties would
+be entirely unchanged, and we would be given to understand that an
+“allotropic” transformation had taken place.
+
+If we can now imagine ourselves as existing under the relative
+conditions described above, which are undoubtedly the “natural”
+conditions of some other world, it will then be easy for us to
+understand quite clearly some of the other “allotropic” forms of iron
+and steel than those with which we are at present familiar.
+
+
+
+
+CHAPTER II.
+
+COMPARISON BETWEEN CONDITIONS WHICH EXIST IN THE IRON AND STEEL FAMILY
+TO THOSE WHICH EXIST WITH MORE FAMILIAR ELEMENTS.
+
+
+One of the first physical changes which we would discover would be that
+when we desired to “freeze” a “crucible” pailful of our iron water, we
+could do so much more easily if the same were in its absolutely pure
+state than we could if it were mixed with some other element, such as
+carbon. Of course, we have long known that this is the case with water
+and salt, and just as it becomes harder and harder to freeze water with
+greater and greater percentages of salt mixed with it, so the freezing
+of iron with greater and greater percentages of carbon mixed with it,
+would also occur at lower and lower temperatures.
+
+If we started to add salt to a pail of water we, of course, would have
+different degrees of brine. Just so with the addition of carbon to a
+crucible of pure iron, we would likewise have different degrees of the
+resulting mixture. In adding the salt to the pailful of water, we would
+arrive at a point where the water had absorbed all of the salt which it
+was capable of holding at room temperature. If we had added a little
+less salt we would have had free water in excess of salt, and if we had
+added a little more salt it would have been impossible for the water to
+have dissolved it, and we would, therefore, have had salt in excess of
+water.
+
+For convenience we will call the mixture above mentioned, at which the
+water had become thoroughly saturated with the salt, “cementite”,
+because this is the name which our friends, the metallurgists, have
+given to a similar mixture of iron and carbon. They call the water,
+“ferrite”; the salt, “carbide” and the resulting mixture of brine,
+“cementite”. This mixture of iron and carbon always exists in exactly
+the same ratio, namely, 93.4% iron and 6.6% carbon, and is expressed
+chemically by the symbol Fe3C, which means, in other words, that three
+“atoms” of iron have united with one “_atom_” of carbon to form the
+“chemical compound”, “iron carbide”, which the metallurgists, as above
+mentioned, desire to term “Cementite”.
+
+Now let us go back to the brine solution with which we are already
+familiar, and suppose that we added a little more salt than the water
+could absorb, and which therefore would exist in a “solid solution”,
+and then bring this “mechanical mixture” to such a low temperature that
+it would actually “freeze”. For convenience, and in order to agree with
+the metallurgists again, let us call the resulting structure
+“pearlite”. That is the name which they have given to a corresponding
+“mechanical mixture” of cementite and ferrite.
+
+This new constituent “pearlite” contains approximately O.9% carbon and
+consists of inter-stratified layers or bands of ferrite and cementite.
+
+It is regarded as a separate and distinct constituent of steel, and
+takes its name from the fact that it has a mother of pearl-like
+appearance under the microscope. It always occurs at a definite range
+of temperature and always contains the above mentioned definite
+percentage of carbon.
+
+From the above it may be suspected that a steel containing O.9% carbon,
+consisting entirely of pearlite, forms rather a special and particular
+class of steels, which the metallurgists have decided to dignify with
+the title “Eutectoid Steels”. Having done this much to properly impress
+the unsuspecting probers of their secrets, they decided to call steels
+containing less than this Eutectoid ratio of carbon (0.9% C)
+“Hypo-eutectoid Steels”. These steels, of course, contain certain
+definite amounts of pearlite with other amounts of free or excess
+ferrite. Likewise, if the carbon content is greater than O.9% there
+will be an excess of cementite over the ferrite and we will then have a
+structure of pearlite plus free cementite. And these steels are spoken
+of as “hyper-eutectoid” steels.
+
+[Illustration: Hypo-eutectoid Steel. Carbon .11%. Structure:
+Light—Ferrite; Dark—Pearlite. Mag. 500x]
+
+[Illustration: Hypo-eutectoid Steel. Carbon .37%. Structure:
+Light—Ferrite; Dark—Pearlite. Mag. 500x]
+
+[Illustration: Eutectoid Steel. Carbon .90%. Structure: Fine uniform
+Pearlitic condition. Mag. 500x]
+
+[Illustration: Hyper-eutectoid Steel. Carbon 1.20%. Structure:
+Dark—Pearlitic; White boundaries—Cementite. Mag. 500x]
+
+
+
+
+CHAPTER III.
+
+AN EXPERIMENT PERFORMED WITH A PIECE OF PEARLITIC STEEL.
+
+
+However, let us not trouble ourselves with too many definitions at one
+time, but instead amuse ourselves for a while by running through a
+little experiment with a piece of carbon tool steel similar to that
+which we have just been discussing. For our investigation we will also
+need a special kind of thermometer for measuring high temperatures.
+Such an instrument is known as a “pyrometer”. Now we will drill a
+little hole in the test piece of carbon steel and after inserting the
+“couple” of the pyrometer into it, place the same in the electric
+furnace.
+
+As the current is turned on, the test piece begins to grow warm and
+then hotter and hotter, gradually up through a range of temperatures
+which are continually recorded by the needle of the pyrometer. 800,
+900, 1000, 1200 degrees Fahrenheit are uniformly reached, and the
+temperature of our test piece continues to rise, as the absorption of
+heat progresses. Suddenly, however, the test piece assumes a bright
+glow and the needle of the pyrometer ceases to advance, and we note
+that it is pausing at about 1350 degrees Fahrenheit. Then after its
+pause, the advance is again resumed until the piece has become almost
+ready to melt. By plotting the uniform periods of time at which we read
+the different temperatures recorded by the needle of the pyrometer,
+against the temperatures as read, we would have a picture of our
+phenomenon something as follows:
+
+[Illustration: Graph showing the course of the temperature curve as a
+function of the heating time of the metal sample.]
+
+Now let us begin to let our test piece cool off gradually. The
+temperature of the furnace is lowered and the uniform range of cooling
+temperatures is recorded by the ever sensitive needle of the pyrometer.
+Suddenly as before, the test piece assumes the brilliant glow noted
+previously, and again the needle comes to rest, but this time we note
+that the recorded temperature is about 1250 degrees Fahrenheit instead
+of 1350 degrees Fahrenheit as before. Evidently there has been a
+certain tardiness or “lag” which has caused the phenomenon to take
+place a little too high going up and a little too low coming down, and
+in fact the metallurgists tell us that such is exactly the case, and
+that the real point in which we are interested lies just half way
+between the two points indicated, as we shall presently see. If we
+again represent the results of our latest experiment graphically, we
+would have a picture something as Fig. 2.
+
+[Illustration: Graph of the cooling curve of the metal sample
+over time]
+
+Now placing the second curve so obtained on the first, we are able to
+study the following interesting relationship. Fig. 3.
+
+[Illustration: Graph combining the heating- and cooling-curves from
+before and demonstrating the critical range]
+
+It is natural to suspect that both of the parallel sections of our
+curves have something to do with the same thing, and for convenience
+since we noticed that mysterious glow of the test piece just as the
+needle came to rest, we might call the particular point which lies just
+half way between the temperatures under discussion, the point of glow,
+or as the metallurgists call it, the “point of recalescence” and the
+range between these two temperatures the “critical range”.
+
+I suppose it would be difficult to explain this phenomenon of the test
+piece unless we imagine that as the critical range is reached some
+internal reaction of the steel causes it to spontaneously take on heat
+at the same temperature in the first place and give off the stored heat
+at the same temperature as the piece was being cooled down, and this
+heat caused it to glow as was noticed. Now if we were to experiment
+further with our piece while at the critical range, we would find
+certain other remarkable changes, one of the most noticeable of which
+is the loss of magnetism at and above the critical range.
+
+Irons and steels are usually the most magnetic materials, but the
+attraction of the magnet is completely lost at or above the critical
+range.
+
+We can easily satisfy ourselves in this respect by noting the
+attraction of a simple horse shoe magnet when our piece of test steel
+is brought into its magnetic field. As the pyrometer needle passes on
+up through the range of temperatures noted above, the magnetic
+attraction is perfectly evident when suddenly the recalescence point is
+reached, the spell is broken and the magnet and the test piece fall
+apart. But let us just consider this phenomenon a moment. We are told
+by the physicists that magnetism is induced in a piece of iron or steel
+by a “rearrangement of the internal molecular structure, in which the
+positive ions face one direction and the negative ions in the opposite
+direction”. Therefore, if magnetism suddenly ceases to exist it would
+seem as if something had happened to the “internal molecular structure”
+of the test piece. Thus when the recalescence point is reached we may
+conclude that something more than a mere absorption of heat units has
+taken place. In fact we may really believe that an actual internal
+molecular revolution has occurred and that some of the natural laws
+which formerly had governed all of these little molecules which go to
+make up the whole piece of steel, have been overthrown and that the
+molecules are more or less free to set up a new form of government for
+themselves, and that, therefore, when a piece of steel is brought to
+the recalescence point it is really in a very sensitive condition. In
+fact, if we should care to investigate further we should find that
+certain other great changes take place at this critical point, such,
+for instance, as partial failure of the test piece to conduct an
+electric current, which formerly, of course, it did with great ease.
+Also when the critical range is reached, a peculiar contraction of size
+interrupts the gradual expansion which had been developing as the test
+piece absorbed heat units, and therefore these several observations
+give us reason to believe that our conclusions as noted above must be
+more or less correct.
+
+Now if all steels acted exactly like the little test piece which we
+have been observing above as they were placed in the hardening furnace,
+it would not take us very much longer to finish our preliminary
+investigations. You remember the piece of steel which we have been
+investigating was a piece of simple carbon tool steel, containing about
+0.90% carbon. But all steels do not contain just this same percentage
+of carbon, and may also contain various elements other than carbon, all
+of which produce many and varied results during the process of heating,
+treating and hardening.
+
+In order to better visualize the investigation which we are making, let
+us picture graphically each step which we take. If therefore, we let
+the vertical lines represent the different carbon contents which steel
+might have, and the horizontal lines the different degrees of
+temperatures through which we might desire to heat the steel under
+discussion and then plotted the phenomenon described above we would
+have a picture something as follows:
+
+[Illustration: Graph showing the point of recalescence]
+
+Now all that picture means is that as we heated up a piece of simple
+carbon tool steel containing O.9% C, we discovered a certain very
+noticeable reaction which occurred just about half way between 1250
+degrees and 1350 degrees Fahrenheit, which we decided to call the point
+of recalescence, and then on further heating of the piece no other such
+phenomenon was noticed.
+
+Now let us go through the same experiment with a piece of steel
+containing .45% C. Yes, just as before, as the temperature 1250 degrees
+Fahrenheit is reached we note all the strange symptoms which are
+characteristic of the point of recalescence and then, just as we are
+about to decide that it is hardly necessary to go further we notice
+that the pyrometer needle has again come to rest, but that this time it
+is registering 1390 degrees Fahrenheit. Therefore, it would seem as if
+this piece had two critical ranges instead of one and we are now quite
+ready to again proceed with our heating to see if anything else occurs.
+However, as nothing does happen we turn to our picture and plot the two
+points just observed, together with the one point found on our first
+investigation, and the drawing then looks something as follows:
+
+[Illustration: Graph additional shows the recalescence of a 
+second sample containing a different rate of carbon]
+
+Now let us take a piece of carbon steel as before, but this time
+containing .15% carbon, and again proceed with our observations. Again
+the needle of the pyrometer records the point of recalescence and also
+the point designating the second range of critical temperature, but
+this time strange to say, as the test piece continues to absorb heat, a
+third critical range is registered, all of which when added to our
+former picture gives a result something as follows:
+
+[Illustration: Graph showing different behavior of
+samples containing different rates of carbon]
+
+By repeating the operations as outlined above, with pieces of steel
+containing various percentages of carbon from zero to 1.25% and by
+plotting the different critical temperatures so obtained, we finally
+obtain a chart which graphically expresses the critical ranges of iron
+and steels due to the variation of the carbon content. With very low
+carbon steel it is interesting to note that the first critical point
+would not occur until 1395 degrees Fahrenheit was reached.
+
+Metallurgists have long designated the lines so obtained by letters,
+“r”, standing for, “refroidissement”, which is the French word meaning
+“cooling”, the suffixes 1-2-3 simply standing for the lines in the
+order drawn.
+
+From the completed chart it is further evident that our first piece
+containing 0.9% carbon in one way is the most interesting of all since
+it is the only case where only one point of critical temperature
+occurs.
+
+It will be noticed from the chart that steels containing less than .10%
+carbon have no point Ar1 and it is therefore undoubtedly due to the
+carbon content that this, the point of recalescence, occurs. From tests
+which we made with the magnet we would also find that the temperatures
+at which loss of magnetism occurs are those designated by the line Ar2,
+whereas the loss of ability to conduct an electric current occurs at
+the point designated Ar3. In steels containing .45% carbon to .75%
+carbon loss of magnetism and loss of ability to conduct an electric
+current occur at the same points designated on our chart by the line
+Ar3-2; whereas in the steel containing .90% carbon—all these changes
+take place at the same time.
+
+Now, as we concluded before, it is evident that some internal change
+must have taken place in the steel itself, and as we know that the
+chemical content does not vary, it is further evident that the change
+must be of a physical nature, or as in the language of the
+Metallurgist, an “allotropic change”. Therefore, another conclusion
+which we can draw at this point is that a very much more thorough
+investigation is required for the proper handling of steel at high
+temperatures than a mere knowledge of the chemical analysis of the
+same.
+
+There is one very fortunate circumstance connected with the passing
+from one of these allotropic changes to another, and that is that the
+effecting of one of these changes takes =time=. It does not take a very
+long time, however, for in some instances the change is affected in a
+very small fraction of a second, while rarely more than one or two
+seconds are required. The higher the temperature the quicker the
+change.
+
+Would it not be interesting if we had been so constructed as outlined
+in the beginning of this little volume; that we could have withstood
+the high temperatures in which some of these very interesting changes
+occur, because we could then handle the steel, examine it and
+experiment with it at our leisure. However, such not being the case, we
+will have to derive some other means for “catching” the steel while it
+is in one of these interesting conditions, and then bringing it in its
+entrapped condition down to room temperature. How shall we do it? Well,
+we remember that we said it took =time= to effect the changes under
+discussion and furthermore we remember that the changes can only take
+place when the steel is within the proper critical range. Therefore, if
+we could do something to lower the temperature of a piece of steel
+while in one of the critical ranges before the steel had time to effect
+the usual allotropic change of form, we might be able to catch a piece
+of steel while in one of these unusual conditions, before it had really
+had time to get back to normal.
+
+Therefore, let us place a piece of .9% carbon tool steel in the heating
+furnace and bring it up to and beyond the point of recalescence. Now,
+grasping the piece firmly in a pair of tongs with all possible speed we
+plunge it into a nearby pail of ice water, keeping the steel
+constantly in motion. Almost instantly the steel becomes black and
+within a few seconds is actually brought down to room temperature.
+
+Now let us take the steel out and examine it. The act of tapping it on
+the anvil in order to knock off the surplus water gives us a hint that
+our test piece has undergone some sort of a change. For now it rings
+with a bell-like clearness and gives the hammer with which we strike it
+a quick snapping rebound which in itself indicates great hardness.
+Next, we test the piece with a hardened steel file with which we could
+easily have made a deep ridge before we attempted the heating operation
+and to our surprise the file has as little effect as if it had been
+made of wood. And to our surprise on closer examination, we actually
+find that our test piece has scratched the file—surely it must be very
+hard. We are convinced that some marked change must have taken place.
+What can it be? Why it must be that due to the rapid cooling in the
+pail of ice water we brought the temperature of the test piece down
+below the critical range =before= the abnormal condition at which it
+existed while at and above the critical range had found =time= to
+change back to its former condition. And we remember that if one of
+these allotropic changes is going to take place at all, nature says it
+=must= do so while the steel is within the critical range and therefore
+having forced the steel through that critical range which separates one
+allotropic condition from another, before it had found =time= to effect
+its desired change, we managed to entrap the abnormal condition so that
+we could see it and feel it and get familiar with it at room
+temperature.
+
+If we so desire we can now make other hardness tests on our piece of
+steel at our leisure. For these scientists have invented several
+machines. One of the most common is called the scleroscope in which a
+hardened steel ball is allowed to drop from a given height on to the
+piece of steel to be tested. Then the rebound of the ball is carefully
+noted. The higher the rebound, the harder the piece. That is natural
+isn’t it? We know that if the ball were allowed to drop on butter, it
+wouldn’t rebound at all, because the butter is so soft. A piece of wood
+would possibly record a very tiny rebound, while a piece of hardened
+tool steel would effect a very material action of the scleroscope ball,
+thus indicating extreme hardness.
+
+Now let us take our test piece to the grind stone and grind it down to
+the shape of a cutting tool. It is necessary to resort to the grind
+stone, in order to get the desired shape, because of course, our test
+piece is far too hard to cut with any other metal. After having
+produced a tool of the desired shape and size, let us fasten the same
+securely into the carriage of a lathe, and then upon applying the
+cutting edge to a revolving piece of cast iron, or soft steel, or even
+to a piece of the very same grade of steel out of which the tool was
+made, only while it is still in the softened or annealed condition, we
+find that it is capable of easily and quickly cutting out a good sized
+ribbon of chips from the metal which is to be machined.
+
+However, we are soon confronted with a new difficulty, for as the cut
+progresses, our tool runs into a rough spot which causes it to tremble
+and chatter and then suddenly our tool cracks in two in the middle and
+is at once completely ruined.
+
+It is evident that as we are able to increase the desirable element of
+hardness in a piece of tool steel, we also automatically increase the
+undesirable element of brittleness, and therefore some new method must
+be devised which will allow a sufficient degree of hardness to allow
+the tool to cut other metals and at the same time not cause so much
+brittleness that it will crack in two at the first rough spot which it
+encounters.
+
+One method of assisting the toughening of a piece of hardened tool
+steel is accomplished by the process of “drawing”. This simply means
+heating the piece of hardened tool steel up to some fairly warm
+temperature, which of course must be kept well below the critical range
+(at which the steel would jump at the chance to quickly change back
+into one of its softer allotropic forms) and then keeping the steel at
+this drawing temperature for a while until the unusual strains and
+stress caused by the rapid cooling have had an opportunity to have
+become somewhat relieved. Therefore, the process of “drawing” is quite
+as important as is the first act of hardening itself, and great care
+must be exercised in undertaking the same.
+
+
+
+
+CHAPTER IV.
+
+HIGH SPEED STEELS.
+
+
+After the processes of hardening and drawing our sample of simple
+carbon tool steel have become thoroughly mastered, it might seem that
+all which was desired had been accomplished and that we could go on
+indefinitely making and using our simple carbon steel tools. However,
+when the extraordinary demands of modern industry required faster and
+faster cutting speeds, and deeper and deeper cuts, we commenced to
+realize that our familiar carbon tool steels would not fill the bill.
+This was due to the fact that as the tools became pressed with the
+faster speeds and deeper cuts, they could not do their work without
+becoming over-heated by the friction caused by the work of upsetting
+the chip and therefore the critical temperature was rapidly approached.
+Of course we know that if this temperature should be reached the steel
+would quickly lose its hardness and its cutting edge would therefore be
+completely ruined.
+
+Therefore, it was necessary to develop a new kind of steel to meet a
+new and severe condition and accordingly the mother of experiment and
+invention gave birth to the now famous “High Speed” Steel.
+
+The general principles applying to the hardening and drawing of High
+Speed Steel are in many ways the same as described above for the simple
+carbon steel, except that as we begin to add various elements other
+than carbon to the melt, the resulting alloy becomes more and more
+complex in its form and reactions and therefore its heat treatment
+causes greater and greater study and skill in its successful
+undertaking.
+
+It is generally known among tool hardeners that it is necessary to heat
+the tool to a higher degree of temperature in order to secure proper
+hardness when using High Speed Steel than it is when a simple Carbon
+Tool Steel is employed. We are told that the introduction of certain
+elements into the melt of a simple Carbon Tool Steel has the tendency
+to change the critical range. Of course, the formulas used in the
+manufacture of any high grade High Speed Steel contain very appreciable
+amounts of various elements other than Carbon which materially effect
+the property which the steel will have when hard. The effect which
+these elements appear to produce in the period of critical range can be
+seen from figure 7.
+
+[Illustration: ≈HEATING AND COOLING OF HIGH SPEED STEEL SHOWN IN FIG.
+12.≈]
+
+In this case an experiment was made with a piece of High Tungsten High
+Speed Steel similar to the experiment which was described in detail
+above with the test piece of simple Carbon Tool Steel. The readings of
+the pyrometer were carefully recorded and when plotted on the graph
+sheet produced the picture under discussion.
+
+Here it will be noticed that the vivid reaction, which we might have
+expected would occur as the temperature indicating the first critical
+range was reached, was materially reduced. This might lead us to
+suspect that the desired allotropic change had not completely taken
+place at this point. In fact we noticed that the pyrometer needle did
+not record a vivid critical point until a very much higher temperature
+was reached. All of these observations serve as a possible explanation
+or indication of why it is necessary to employ very much higher
+temperatures in the hardening of High Speed Steel than it is in the
+hardening of a piece of simple Carbon Tool Steel.
+
+In a later chapter of this little volume we define Carbon Steels as
+those which do =not= contain enough of any element other than carbon to
+materially affect the physical properties which the steel will have
+when hard. High Speed Steels which are one of a very important group of
+special alloy steels, are those steels to which some element =other=
+than carbon has been added in sufficient amount to materially effect
+the physical properties which the steel will have when hard.
+
+The element which stands out alone as the most vital and important one
+as affecting the wonderful and highly desirable features looked for in
+High Speed Steels is Tungsten. We will discuss the various effects
+which the different elements give to the different alloy steels in a
+later chapter, but for the present we will confine ourselves to a brief
+discussion of the heat treatment of the now famous modern High Speed
+Steel.
+
+[Illustration: High Speed Steel. Carbon .58%. Structure: Very fine
+pearlitic condition, with particles of free carbide. Mag. 500x]
+
+As previously suggested the pressing demand of modern industry for
+quicker work, greater efficiency and enormously increased out-put of
+product, gave rise to the necessity of producing far more remarkable
+tools than was possible with the old fashioned carbon tool steel.
+Therefore it became necessary to produce a steel which could be
+rendered sufficiently hard to cut deep furrows in the various metals
+which have to be machined and, which could be made sufficiently tough
+to stand the enormous cutting strains and chatter and vibration of the
+machine, and at the same time maintain all these characteristics when
+the work done by upsetting the chip of the machined member actually
+rendered the cutting edge of the tool red hot.
+
+After the seemingly impossible task of producing a steel to meet these
+terrific conditions had been successfully accomplished, the next
+question which arose was to produce a machine which was sufficiently
+powerful to stand the work done by the tool, and so fast has been the
+progress made by the tool steel producer, that many of our modern
+manufacturing industries of today are constantly having to introduce
+new and heavier machinery into their various machine shop and tool
+rooms in order to keep pace with the possibilities of the tool made
+from the modern High Speed Steel.
+
+Now, if we were to run an experiment with a test piece made from High
+Speed Steel similar to the one which we ran on the simple Carbon Tool
+Steel, we would find that many of the same phenomena previously noticed
+would again be recorded.
+
+Probably the most important difference would be the fact that instead
+of having to quench the same in water it would be desirable to use a
+bath of oil. In fact, water would cause the High Speed Steel to cool
+off far too quickly so that it would be likely to crack and be rendered
+useless.
+
+A peculiar action of the various elements in High Speed Steel is very
+likely to materially retard the change of one allotropic form into
+another. In fact, the change is so slow that after a piece of High
+Speed Steel has been heated above the critical temperature, it will
+actually retain its hardened or austenitic condition even if allowed to
+cool in the air, and it would only be possible to get it back into its
+softened condition by the lengthy process of annealing.
+
+Annealing is the process of undoing exactly what the act of hardening
+accomplished. Long tubes are filled with the tool steel bars and sealed
+from the air and then placed into the annealing furnaces, wherein the
+annealing temperature is maintained for a sufficient number of hours,
+until the steel has had an opportunity to become thoroughly softened.
+
+
+As before stated “drawing” or “tempering” means the careful re-heating
+of the steel to 400 degrees Fahr. to 600 degrees Fahr., thus allowing a
+slight “slipping” of enough of the higher allotropic solution to a
+lower form, which it is always eager to accomplish at temperatures near
+the point of recalescence. This, of course, relieves the excess
+brittleness of the hardened steel.
+
+
+Annealing is the complete release of the higher allotropic form of the
+solution and the “trapped” carbon which allows of their return to the
+normal condition of pearlite and alpha iron. Therefore, it is necessary
+to heat the steel above the point of recalescence and cool more or less
+slowly. Different speeds of cooling give different grain, size,
+structure and physical property.
+
+This explanation of hardening, which is known as the “allotropic
+theory” is not universally accepted, although it is difficult to find a
+better or more complete explanation of the remarkable phenomena
+involved. However, the fact remains that the great accomplishments
+which have been made by the men of science and understanding have
+caused remarkable results to have taken place in the manufacturing
+world of today and the fine and obscure lines which these patient and
+careful laborers are continually drawing upon the map of knowledge are
+doing much to make the world a better and safer and more wonderful
+place in which to live.
+
+
+
+
+CHAPTER V.
+
+THE GENERAL EFFECT OF THE MORE IMPORTANT ELEMENTS IN TOOL STEELS.
+
+
+We know that all metals of engineering nature are crystalline in
+character, that is, the crystals form when the metal solidifies. If
+these crystals were free it would be easy to determine definitely just
+what properties the metal would have. However, the crystals are not
+free, but exist in the steel in combination with many other types of
+crystals. This results in many complicated and complex possibilities in
+the finished product, and will bring us presently to the subject of
+“Alloy Steels”.
+
+
+CARBON STEELS.
+
+Carbon Steels are those which do =not= contain enough of any element
+=other= than carbon to materially affect the physical properties which
+the steel will have when hard. Carbon is one element used above all
+others by manufacturers in getting required physical properties. An
+increase of one hundredth of one per cent (.01%) gives a tensile
+strength of about one thousand pounds per square inch, but even this
+amount of carbon also regularly decreases the ductility of the finished
+product. When steel is heated red hot and plunged into water, the
+carbon in the metal unites with the iron in some peculiar way so that
+it produces a compound of extreme hardness. If the steel contains
+nine-tenths of one per cent (.90%) of carbon, a sharp point so quenched
+will almost scratch glass. With one per cent (1.00%) of carbon it
+reaches nearly its limit of hardness. Now carbon steels with this
+percentage carbon can be used for some of the harder tools, which do
+not require much ductility or toughness, but with higher carbon
+contents than this percentage, the brittleness increases so fast that
+the usefulness of the metal is decidedly limited.
+
+Therefore, when the steel must meet requirements other than just that
+of hardness, such as, strength, ductility, toughness, resistance to
+repeated shock, “red hardness”, etc., then it is necessary to resort to
+other means and combinations for obtaining the required needs. It is to
+be remembered that such methods and combinations will materially
+increase the cost of the final product.
+
+
+ALLOY STEELS.
+
+What is an alloy steel? The general definition of an alloy steel is, “a
+solidified solution of two or more metallic substances”. The
+International Committee upon the nomenclature of iron and steel defines
+alloy steels as “those steels which owe their properties chiefly to the
+presence of an element (or elements) =other= than carbon”.
+
+This latter definition more nearly applies to our case, but it must be
+born in mind that the distinction between an element added merely to
+produce a slight benefit to ordinary carbon steel, and the very same
+element added to produce an alloy steel itself, is sometimes a very
+delicate one. For example: Manganese is added in amounts usually less
+than 1.50% to all Bessemer and Open-Hearth Steels, for the purpose of
+getting rid of oxygen, and neutralizing the effect of the sulphur. But
+this does not produce an Alloy Steel. When we make “manganese steel”
+containing 10 to 20% manganese, the material then has properties quite
+different from the same steel without the manganese, and we then have a
+Manganese Alloy Steel.
+
+Thus, for our purpose, we may consider an alloy steel as being one to
+which some element =other= than carbon has been added in sufficient
+amount to materially affect the physical properties which the steel
+will have when hard.
+
+
+HIGH SPEED STEELS.
+
+High Speed Steels are perhaps the most important of alloy steels, and
+derive their name from the fact that they can be used as cutting tools
+when the cut on the machined member is being made at a high speed.
+This, of course, subjects the tool to severe operating conditions,
+which simple carbon steels could not stand. These steels have other
+notable characteristics, among which is that of “self-hardening” or
+“air-hardening”, as it is sometimes called. This means, when the steel
+cools naturally in the air, from a red heat or above, it is not soft
+like ordinary steel, but is hard and capable of cutting other metals.
+
+Another striking characteristic of high speed steels is their ability
+to maintain a sharp cutting edge while heated to a temperature far
+above that which would at once destroy the cutting ability of a simple
+tool steel. Because of this property, a tool made of high speed steel
+can be made to cut continuously at speeds three to five times as great
+as that practicable with other tools. The result of the friction of the
+chip on the tool may cause the tool to become red hot at the point on
+top where the chip rubs hardest, and the chip may, itself, by its
+friction on the tool, and the internal work done on it, by upsetting
+it, be heated to a blue heat, or even hotter.
+
+
+ELEMENTS WHICH OCCUR IN ALL STEELS.
+
+There are certain elements which are practically always found in =any=
+kind of steel. These elements are capable of producing many varied
+effects on the finished product. They are Iron, Carbon, Manganese,
+Silicon, Phosphorous and Sulphur.
+
+
+IRON.
+
+The base of all steels is Iron. It goes without saying that this
+element should be obtained in the best and purest state possible.
+Probably the best “base” iron comes largely from Sweden, which country
+seems to have produced the highest quality of iron on the market today.
+
+
+CARBON.
+
+Carbon has already been discussed under Carbon Steels, although, of
+course, its importance in Alloy Steels must not be under-estimated. The
+proportion of carbon aimed at in high speed tool steels is about 0.65%,
+which in simple steel would not be enough to give the maximum hardness,
+even if the steel were heated above the critical point and quenched in
+water, and still less so when the steel is cooled as slowly as these
+steels are in their treatment. This shows that the carbon element acts
+in a different way from what it does in simple carbon steels as
+previously discussed.
+
+
+MANGANESE.
+
+Manganese Steel is a typical self-hardening steel and so, obviously, is
+any steel which is in the austenitic condition at atmospheric
+temperatures, that is to say, whose critical temperature is below
+atmospheric temperature. Thus, self-hardening steels are non-magnetic.
+Because of its low-yield point, manganese steel does not give
+satisfaction in many lines, for which otherwise it might be eminently
+fitted.
+
+Manganese used in =small= quantities (.30% to 1.50%) will produce
+certain desired effects. Under these conditions it acts as a purifier.
+And when added in the form of Ferro Manganese to a heat of steel it
+unites with the oxygen and transforms it to slag as oxide of manganese.
+There is also good reason for believing that manganese prevents the
+coarse crystallization, which impurities such as Phosphorus and Sulphur
+would otherwise produce. Five per cent to 14% manganese renders the
+steel non-magnetic as well as a poor conductor of electricity.
+
+
+SILICON.
+
+The dividing line between silicon-treated steels and silicon-alloy
+steels is not clearly defined, but the latter are used for several
+important purposes.
+
+Such steel has been used in springs of the leaf type for automobiles
+and other vehicles, the silicon being considered to add slightly to the
+toughness of the springs. However, the most important use of steels of
+this type is probably in the manufacture of electrical machinery. It is
+possible to produce a silicon-alloy steel which has not only a greater
+magnetic permeability than the purest iron, but also, a high electrical
+resistance. Its hysteresis is, of course, low, this property always
+accompanying a high permeability. It therefore is a very valuable
+material for use in electro-magnets, and in electric generating
+machinery, is the most efficient material known.
+
+In silicon-treated steels, the silicon is used somewhat as a scavenger,
+although it also produces results somewhat similar to manganese.
+
+
+PHOSPHORUS.
+
+Phosphorus has little effect upon the hot properties, but in the cold
+state makes the steel brittle and is of course highly undesirable
+although some writers have claimed that it adds to the tensile strength
+in about the same degree as carbon.
+
+
+SULPHUR.
+
+Sulphur has just the opposite effect of Phosphorus, and makes the steel
+crack while it is being hot worked, although after the metal is cold it
+seems to have no particular effect upon the physical properties.
+
+
+ELEMENTS WHICH HAVE BECOME
+ESPECIALLY ASSOCIATED
+WITH SPECIAL
+ALLOY STEELS.
+
+Such elements are:—Chromium, Tungsten, Molybdenum, Vanadium, Cobalt,
+Uranium, Titanium, Aluminum, etc.
+
+
+CHROMIUM.
+
+Chromium is an indispensable constituent in modern high speed steel,
+and does not make a poor high speed steel, even when used alone. The
+chief effect which chromium produces in high speed steels is
+undoubtedly that of “hardening”. However, chromium, like carbon, will
+produce brittleness, if added in too large quantities, although if kept
+down to between 2 to 5% it seems to allow the lowering of the carbon
+element, while at the same time maintaining the desired hardening
+effect, without causing undue brittleness. The great hardness in the
+face of an armor plate, and the great toughness in the back of the
+plate, also the superb properties in the projectile which attempts to
+pierce the plate, can all be induced in chromium steels to a degree
+unattainable by the use of any other single element.
+
+As a simple chromium steel the product may be used in five-ply plates
+for the manufacture of safes. These plates are made of five alternate
+layers, two of chrome steel and three of soft steel, and after having
+been hardened, offer resistance to the drilling tools employed by
+burglars. Hardened chromium rolls are manufactured for use in
+cold-rolling metals. Files, ball and roller-bearings are other noted
+products of this type of steel. It is the essential constituent of
+those steels which neither rust nor tarnish.
+
+
+TUNGSTEN.
+
+It was soon found that the composition of “self-hardening” steels was
+not the best one for high speed steels. Tungsten was discovered as an
+element which gave the steel properties of hardness and toughness at a
+red heat. After the peculiar heat treatment had been learned, and the
+presence of manganese or chromium in addition to the tungsten was shown
+to be unnecessary in appreciable amounts, it was found that more
+durable qualities could be obtained by increasing the percentage of
+tungsten, while at the same time the carbon element was greatly
+reduced.
+
+The best grade of High Speed Steel ought to have a tungsten content of
+about 18.00% and a carbon content of about 0.65%. Thus whenever a steel
+is needed which must operate under especially severe conditions, this
+would be the steel to use. Such conditions are usually met in the case
+of rapid turning, boring, planing, slotting and shaping tools, also
+with twist drills and all forms of milling cutters, gear cutters, taps,
+reamers, special dies, etc.
+
+
+MOLYBDENUM.
+
+Molybdenum was once thought of as being somewhat in a class with
+tungsten, but its use in high speed tool steels is being generally
+discontinued. The reason for this is that it was found that in rapid
+steels this element caused irregular performance, such as large
+variations in the cutting speeds which they would stand. This element
+is also likely to make the steels seamy and contain physical
+imperfections. Molybdenum steels were also found to crack on quenching,
+and possess decided variations in internal structure.
+
+
+VANADIUM.
+
+Vanadium steels are still in their infancy. Therefore, the true value
+of this element in rapid steels must probably be held as not yet fully
+determined. With the single exception of carbon, no element has such a
+powerful effect upon steel as vanadium, for it is only necessary to use
+from 0.10 to 0.15% in order to obtain very noticeable results. In
+addition to acting as a very great strengthener of steel, especially
+against dynamic strains, vanadium also serves as a scavenger in getting
+rid of oxygen and possibly nitrogen. It is also said to decrease
+segregation, which we may readily believe, as most of the elements
+which quiet the steel have this effect.
+
+“Vanadium Steels” demand a somewhat higher price than do those steels
+which do not contain this element in appreciable amounts. It is, of
+course, especially useful for all purposes where strength and lightness
+are desired, such as springs, axles, frames and other parts of railroad
+rolling stock, and automobiles.
+
+
+COBALT.
+
+The valuable effect of cobalt is claimed to be that it increases the
+red hardness of high speed tool steel, enabling the steel to cut at a
+higher speed. However, this element much resembles nickel, which has
+been largely condemned as not being a desirable ingredient for high
+speed tool steels, because it has the effect of making the edge of the
+finished tool soft or “leady”.
+
+
+URANIUM, TITANIUM AND ALUMINUM.
+
+These elements are generally classed as scavengers, although recently
+important claims have been advanced for their effect upon the physical
+properties of steel. This is especially true for the first two. In
+present practice, however, they are used almost entirely as deoxidizers
+or cleansers, and are added to the metal for this purpose only.
+
+
+IMPURITIES.
+
+Phosphorus, Sulphur and Copper are the most noted impurities which
+occur in steel. The first two are practically always present in greater
+or smaller amounts as the case may be. The best processes of tool steel
+manufacture are capable of producing steels with no copper. While
+Aluminum is not generally classed as an impurity, it nevertheless
+sometimes shows up in the finished product when its presence is not
+desired, and therefore, might be considered an impurity.
+
+Combinations of iron with some or all of the above elements in the form
+of slags and oxides are other well known impurities.
+
+From the forgoing pages it must be evident that producing a steel with
+exactly the correct chemical content is only =one= step towards
+securing a satisfactory product. However, it might be well if we were
+to briefly sum up a few of the more important features of our
+discussion on this interesting subject.
+
+
+HEAT TREATMENT.
+
+The heat treatment of tool steels is of the utmost importance. Tool
+makers of the old school proved their ability to accomplish certain
+desired results in the art of heat treatment without really fully
+understanding exactly how or why they were able to do so. Today,
+however, progressive manufacturers are using the results of research
+and such thorough scientific investigation that the process has become
+far more complicated and complex, and the results obtained are
+correspondingly more remarkable.
+
+Chemically perfect steel may be easily and completely ruined during the
+process of melting, cogging, rolling, hammering, annealing, heat
+treating and tempering. It is the business of the steel manufacturer to
+carefully guard his product up through the process of annealing, but it
+usually falls to the tool maker to undertake the delicate operations of
+heat treatment and tempering.
+
+
+HARDENING.
+
+The application of heat alone to steel can very materially affect the
+condition of the structure of the metal, either with or without
+simultaneous mechanical treatment. Depending upon the degree of heat,
+the rate of heating and cooling and the duration of such treatment,
+this application may be decidedly beneficial or harmful as the case may
+be.
+
+We now know that when steel is heated above the critical point, and is
+then allowed to rapidly cool, a very marked hardness in the metal is
+produced. The degree of hardness so attained will, in general, vary
+directly with (1) the percentage of carbon, (2) the rate of cooling,
+(3) and the temperature above the critical point from which the cooling
+takes place. When the steel comes from the rolling mill and from the
+finishing hammers it is in this hardened condition. Therefore, in order
+to render it soft and ductile enough to cut and work up into certain
+desired shapes, sizes and tools, it is necessary to subject the steel
+to the process of annealing. This operation is usually undertaken by
+the steel producer, under which circumstances he is able to control his
+product through this delicate procedure, and deliver the same to his
+customers in the best possible condition for their use.
+
+
+ANNEALING.
+
+Annealing has for its object: (1) Completely undoing the effect of
+hardening, leaving the steel soft and ductile (2) refining the grain,
+in which case the crystals are allowed to re-arrange and re-adjust
+themselves, usually growing to a rather large size (3) and removing
+strains and stresses caused by too rapid cooling. Such cooling strains
+are particularly likely to exist where the rate of cooling is different
+in different parts of the bar, but the process of annealing ought to
+remedy any such condition, leaving the steel soft, ductile and of
+refined and uniform crystalline structure throughout.
+
+The process of annealing is easier to explain than it is to actually
+put into practice. The steel is first packed in lime, charcoal, fine
+dry ashes or sand, and then sealed in long air-tight tubes or boxes.
+
+The whole receptacle is next slowly brought up to a dull red heat, of
+about 1500 degrees Fahrenheit.
+
+It is very important to heat the material uniformly all the way
+through, and then hold it in this condition from three to eight hours.
+Thus, allowing the slipping of one allotropic condition into another.
+
+The receptacle must be cooled equally slowly, either allowing the
+packed steel to cool slowly down with the furnace, or by placing the
+same in a soaking or cooling pit, which also accomplishes the desired
+result.
+
+After the receptacle has become entirely cooled it is opened and the
+steel unpacked and removed. The steel is then ready for its final
+inspection before shipping to the tool maker.
+
+
+TEMPERING.
+
+The process of tempering usually has to be undertaken by the tool maker
+or user after the annealed steel, which he received from the steel
+mill, has been cut up and shaped into the desired form and size.
+
+The main object of tempering steel is to re-harden the material to such
+an extent that it will cut other metals, retaining its desired shape
+size and cutting edge, while at the same time it must not possess too
+much brittleness. The treatment varies materially with different brands
+of steels.
+
+For the average grade of the best High Speed Steel containing from 16%
+to 18% tungsten, the tool should be brought very slowly up to a dull
+cherry red. It is usually considered good practice to first place the
+tool near or on top of the pre-heating furnace before actually placing
+it in the pre-heater, in order that the heating might be effected just
+as slowly as possible. The pre-heating operation should bring the tool
+up to about 1600 to 1800 degrees Fahrenheit, after which the tool
+should be placed in the high heating furnace and brought up to 2300 to
+2400 degrees Fahrenheit, or a white sweating heat. Care should be taken
+not to allow the tool to remain in this condition for more than an
+instant, as it is then in a very critical condition and could be easily
+burned or ruined.
+
+Therefore, the tool should be immediately pulled from the furnace and
+plunged into a good clean oil bath, keeping it constantly in motion.
+
+As High Speed Steels are air-hardening steels, it is also the practice
+to harden these steels by simply placing the cutting edge in an air
+blast, which produces maximum hardness in the desired point and allows
+the body of the tool to cool at a little slower rate, thus slightly
+relieving the cooling strains and producing a little less brittleness
+therein. Such cooling strains can be relieved throughout the whole tool
+by drawing the same back to about 400 to 500 degrees Fahrenheit, and
+sometimes as high as 1050 degrees Fahrenheit, depending upon the
+particular tool and its use.
+
+The treatment of Carbon Steels varies with each particular brand. Great
+care must always be taken to heat the steel uniformly, as a material
+which is heated unevenly will expand and contract unevenly and, in
+consequence, will crack when quenched.
+
+The steel should always be hardened on the rising heat, in general
+bringing the same slowly up to a dull cherry red, or to about 1450
+degrees Fahrenheit, and then quenching in clear cold water, keeping the
+same in motion until the steel is cold. The temper should then be drawn
+according to the purpose of the tool, which could only be discussed for
+each particular case. The following range of temperatures are
+interesting, as being approximately indicated by the thin film of oxide
+tints which occur on the tool undergoing a tempering operation:
+
+  Pale Yellow       428 Degrees Fahrenheit
+  Golden Yellow     469 Degrees Fahrenheit
+  Purple            531 Degrees Fahrenheit
+  Bright Blue       550 Degrees Fahrenheit
+  Dark Blue         601 Degrees Fahrenheit
+
+
+
+
+CONCLUSION.
+
+The effects of annealing, rolling, hammering, treating and tempering
+are best understood by those manufacturers who make a specialty of
+supplying a high grade tool steel, and in general it would be well if
+customers would consult freely with the producers of these steels,
+before attempting the delicate undertaking of Heat Treatment.
+
+
+
+
+CHAPTER VI.
+
+WHAT TOOL STEEL IS DOING TOWARDS
+WINNING THE WAR.
+
+
+It hardly seems fitting that we should close these pages without giving
+our readers some little idea of just what the tool steel industry is
+doing for the successful conclusion of the great cause nearest our
+hearts.
+
+One of the first statements which we could make would be that every
+metal worker in the world absolutely requires some form of tool steel
+or special alloy steel in the manufacture of his product. Of course, a
+very great many manufacturers other than the actual metal workers also
+need this same supply of tool steel in order that their production
+might not immediately cease. Volumes could be written on the vital
+importance of tools to industry in general, from the drills which drill
+out the hole in a hypodermic needle, to a twelve-ton drop-forge steam
+hammer. But for the present we may confine ourselves to simply the
+briefest mention of the vast number of iron and steel products actually
+and vitally engaged in the prosecution of the war.
+
+We are told that we need ships, yet the ship industry could not proceed
+a day if its supply of necessary tools was cut off. The overwhelming
+increase in the manufacturing operations of the world which has taken
+place since the opening of the European War can better be imagined than
+explained, it being only necessary for us to point out here that the
+one absolute necessity which is common to all and required by all
+branches of such vast manufacture is the proper supply of necessary
+tools.
+
+It has been the personal duty of the writer to make various visits to
+different Government shops and Arsenals as well as to the plants and
+shops of torpedo, shell and munition manufacturers and the vital part
+which the tools of production are playing in the great undertaking has
+been forcefully impressed upon his attention.
+
+The metals which are destined to play an active part in actual warfare
+are naturally required to meet the most severe conditions imaginable.
+Thus we find the high manganese armor plate and the high
+chrome-manganese armor piercing projectile. We find the new
+specifications for steel forging, for hulls and engines now have rigid
+chrome-vanadium and special nickle requirements, all of which means
+that the tools that do the machining, planing, shaping, cutting,
+drilling, boring, reaming, stamping and many other operations must be
+made of a tougher and harder material than ever before.
+
+We know that for every man who may fight on the battle field, at least
+two men must labor in our shops and factories over mechanical
+operations.
+
+Those of us who have been in immediate touch with some of the vital
+requirements of the War and Navy Departments in these strenuous days
+realize the shocking absence of the complete preparedness, which we
+must rapidly accomplish if we are to come anywhere near supplying our
+own soldiers on the fighting front with the fighting machinery and
+supplies of which they are in such urgent need. We realize that after
+all these months of increased industrial preparedness, we are,
+therefore, still unprepared in the full meaning of the word. The very
+foundation of our structure shows a startling amount of unpreparedness.
+We like to gaze upon the exterior towers and battlements of a castle of
+preparedness, and these are wonderful and encouraging to look upon but
+down below all these are certain neglected and unfinished pillars in
+the unseen cellar of that foundation, which threaten the stability of
+the entire mass. It is, therefore, some of these fundamental details
+which have been neglected as we have beheld the vision of the
+super-structure above. Pershing needs, 1,500,000 boys in khaki and over
+the shoulder of each is his protection against the Hun. Everyone of
+these rifles is a splendid monument of the accomplishment of tool steel
+and special alloy steel.
+
+Every day of our present existence it happens that over a million
+shells scream over the miles of battle line in France. This curtain of
+high explosive and shrapnel is another direct expression of the wonders
+which the modern high speed and special alloy steel have accomplished.
+We are told that a 3“ shrapnel shell contains seventy drilled holes or
+a drilling of 19-1/4” in depth. That means that 1,600,000 feet or over
+three hundred miles of drilled holes are shot away every twenty-four
+hours on the battle fronts of Europe.
+
+In a publication “Fighting Industry” published by one of our largest
+twist drill companies in this country, we note that the drilled holes
+in various implements of our militant harness are as follows:
+
+  8“ shrapnel shell      70
+  Springfield rifle      94
+  Torpedo              3466
+  Machine gun           350
+  Aeroplane            4089
+  3-ton auto truck     5946
+  Light ambulance      1500
+  3” field gun         1280
+  Gun caisson           594
+  Anti-air craft gun   1200
+  Self-binder           500
+  Thresher              420
+  Motorcycle           1160
+
+Four million men must work with tools in order that two million men may
+fight in France. These men can not, “just be given a tool and told to
+use it.” It is necessary that they have years of careful training and
+actual experience in order that they might effectively make use of the
+intricate tools and machinery which the mother of modern industry is
+striving to place in their hands. At present every tool steel mill in
+America is straining its furnaces, hammers and rolling mills to their
+maximum capacity. They are working days, nights and Sundays and still
+the demand is far in excess of the supply. Conservative estimations
+show that with all the added machinery and equipment which is in the
+process of construction at this time, it will still take at least two
+years and a half before the tool steel industry of America will come
+any where near meeting the demand for its product.
+
+As we gaze with belated pride upon the huge structure of our present
+Preparedness, does it not seem strange to think that the most vital
+pillar of its whole foundation should have been forgotten and neglected
+so long and which is therefore now caused to endure such an abnormal
+and terrific strain? We are at last forced to realize that tool steel
+is the very essence of our whole existence.
+
+Of course, the great importance of tool steel in this national
+emergency does not stop with the actual weapons of warfare. Besides the
+railroads, automobiles, tramways, elevators, bridges, buildings,
+shoes, clothing and in fact, every branch of the intricate mass of
+manufactured products so vital to our daily existence, nations are
+crying for bread. Victory hangs on our food supply. Our threshing
+machines, our reapers and our harvesting machinery are all working over
+time. But before the threshing machines can thresh wheat and before the
+reapers can reap and before the tractors and other farm machinery can
+contribute their great service to humanity, it is necessary that the
+American production of tool steel must pass its rigid inspection and
+yield forth in full measure the great service which it is called upon
+to give.
+
+
+
+
+APPENDIX.
+
+ANALYSIS, USES AND HEAT TREATMENT OF
+VARIOUS GRADES OF TOOL STEELS.
+
+
+Providing the many complications and difficulties which accompany the
+melting, hammering, rolling, annealing, inspecting and finishing
+operations, have been successfully accomplished, the chemical analysis
+of the best grades of tool steel should come within the following
+limits:
+
+
+TYPICAL ANALYSIS OF HIGH
+SPEED STEEL.
+
+  Carbon                   .66 %
+  Tungsten               18.01 %
+  Chromium                4.50 %
+  Vanadium                 .98 %
+  Phosphorus               .023%
+  Sulphur                  .021%
+  Manganese                .285%
+  Silicon                  .228%
+  Iron (by deduction)    75.293%
+
+
+USES.
+
+Turning, Boring, Planing, Slotting, Shaping Tools. Also Twist Drills,
+Milling Cutters, Gear Cutters, Taps, Reamers, Special Dies, etc.
+
+
+HEAT TREATMENT.
+
+Heat slowly in pre-heater to 1700 degrees Fahrenheit. Then rapidly in
+superheater to 2300 degrees Fahrenheit, taking care not to burn or
+fuse delicate projections on special tools. Harden either in air blast,
+or in good clean oil; keeping tool in motion. In all cases merely the
+_end_ of the tool to white heat. Draw in oil from 400 degrees
+Fahrenheit to 600 degrees Fahrenheit.
+
+
+TYPICAL ANALYSIS OF DIE
+STEEL FOR HOT WORK.
+
+  Carbon                   .39 %
+  Tungsten                8.41 %
+  Chromium                2.10 %
+  Phosphorus               .019%
+  Sulphur                  .017%
+  Manganese                .315%
+  Silicon                  .234%
+  Iron (by deduction)    88.515%
+
+
+USES.
+
+Hot shear blades, hot punches, header and gripper dies; used in bolt
+and rivet making. Also excellent for compression sets and in general
+for all hot work.
+
+
+HEAT TREATMENT.
+
+Will stand high hardening heats, similar to high speed steel, 1700
+degrees Fahrenheit and then 2300 degrees Fahrenheit. Harden either in
+air or oil. Keep away from water. Draw to 500 degrees Fahrenheit.
+
+
+TYPICAL ANALYSIS OF SPECIAL
+ALLOY STEEL.
+
+  Carbon                   .78 %
+  Vanadium                 .29 %
+  Phosphorus               .014%
+  Sulphur                  .016%
+  Manganese                .324%
+  Silicon                  .296%
+  Iron (by deduction)    98.28 %
+
+
+USES.
+
+Specially useful in tools subject to shock, such as hand and pneumatic
+chisels, boilermakers caulking tools and rivet sets. Also for cold
+upsetting dies, cold punches, shear blades and stamping dies. A special
+grade of this steel makes excellent taps.
+
+
+HEAT TREATMENT.
+
+Heat slowly to a low red, about 1400 degrees Fahrenheit, or if low
+carbon content to 1500 degrees Fahrenheit; being very careful not to
+over-heat. Quench in good clean tempered water; keeping tool constantly
+in motion. Draw from 250 degrees Fahrenheit to 400 degrees Fahrenheit.
+
+
+TYPICAL ANALYSIS OF FAST FINISHING
+SEMI-HIGH SPEED.
+
+  Carbon                  1.28 %
+  Tungsten                3.56 %
+  Phosphorus               .021%
+  Sulphur                  .019%
+  Manganese                .316%
+  Silicon                  .271%
+  Iron (by deduction)    94.533%
+
+
+USES.
+
+Do not confuse the High Speed, although excellent for turning chilled
+cast iron, clean finishing cuts. Especially adapted for taps and
+reamers, as well as for tools for brass, bronze, aluminum, copper and
+chilled roll turning.
+
+
+HEAT TREATMENT.
+
+Heat slowly to full bright red, 1425 degrees Fahrenheit to 1500 degrees
+Fahrenheit. Quench in luke warm water. Keep tool constantly in motion.
+Draw to not over 300 degrees Fahrenheit.
+
+
+TYPICAL ANALYSIS OF SIMPLE
+CARBON TOOL STEEL.
+
+  Carbon                  1.12 %
+  Phosphorus               .009%
+  Sulphur                  .011%
+  Manganese                .254%
+  Silicon                  .213%
+  Iron (by deduction)    98.393%
+
+
+USES.
+
+General tool room usage _with moderate cutting speeds_. Excellent
+lathe, planer, and shaper tools, drills, shear blades (for cold work
+only) punches, chisels, files and mining tools.
+
+
+HEAT TREATMENT.
+
+Heat slowly to Low Red heat, approximately 1375 degrees Fahrenheit (the
+higher the carbon the lower the heat). Care not to over-heat. Quench in
+good clean luke warm water. Draw to not over 350 degrees Fahrenheit.
+
+
+TYPICAL ANALYSIS OF NON-SHRINKING
+OIL HARDENING
+STEEL.
+
+  Carbon                   .91 %
+  Phosphorus               .016%
+  Sulphur                  .019%
+  Manganese               1.62 %
+  Silicon                  .31 %
+  Iron (by deduction)    97.125%
+
+
+USES.
+
+Threading dies, chasers, taps, reamers, and all master tools. For
+gauges, plugs, etc. Especially adapted for stamping, punching, trimming
+dies and many other uses where it is necessary to overcome shrinking,
+warping or change of shape.
+
+
+HEAT TREATMENT.
+
+Heat very slowly to pre-heating temperature of 1200 degrees Fahrenheit,
+then to hardening temperature from 1360 degrees Fahrenheit to 1425
+degrees Fahrenheit, depending upon size of piece being treated.
+
+Harden in lard, linseed or cottonseed oil; preferably fish oil. Do not
+quench in water.
+
+Draw cutting tools, taps and reamers at 250 degrees to 300 degrees
+Fahrenheit. Large tools such as blanking and stamping dies at 400
+degrees to 450 degrees Fahrenheit.
+
+
+TYPICAL ANALYSIS OF SPECIAL
+HOT WORK ALLOY STEEL.
+
+  Carbon                   .86 %
+  Chromium                3.71 %
+  Phosphorus               .023%
+  Sulphur                  .019%
+  Manganese                .381%
+  Silicon                  .267%
+  Iron (by deduction)    94.740%
+
+
+USES.
+
+An excellent composition for hot work in service for grippers, headers,
+hot punches, hot shear blades and similar tools. Especially valuable in
+structural steel and boiler shop work. Rivet sets and bull dies made
+from a steel of this composition ought to resist breaking and
+battering.
+
+
+HEAT TREATMENT.
+
+Very flexible hardening in air, oil or water. If air is used heat to
+1675 degrees to 1750 degrees Fahrenheit and place under dry air blast,
+or stand in cool place. To harden in oil, heat to 1500 degrees to 1550
+degrees Fahrenheit and quench in thin oil. To harden in water, heat to
+1475 degrees Fahrenheit to 1525 degrees Fahrenheit and quench in cool
+water. Draw from 250 degrees to 300 degrees Fahrenheit.
+
+
+
+*** END OF THE PROJECT GUTENBERG EBOOK 75326 ***