Heat Treatment Of Steel
: HEAT TREATMENT OF STEEL: The Working Of Steel
Heat treatment consists in heating and cooling metal at definite
rates in order to change its physical condition. Many objects may
be attained by correct heat treatment, but nothing much can be
expected unless the man who directs the operations knows what is
the essential difference in a piece of steel at room temperature
and at a red heat, other than the obvious fact that it is hot. The
science of metallography has been developed in the past 25 years,
and aided by precise methods of measuring temperature, has done
much to systematize the information which we possess on metallic
alloys, and steel in particular.
More
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For Milling Cutters And Formed Tools
FORGING.--Forge as before.--ANNEALING.--Place the steel in a pipe, box or muffle. Arrange the steel so as to allow at least 1 in. of packing, consisting of dry powder ashes, powdered charcoal, mica, etc., between the pieces and the walls of the box ... Forging High-speed Steel
Heat very slowly and carefully to from 1,800 to 2,000 deg.F. and forge thoroughly and uniformly. If the forging operation is prolonged do not continue forging the tool when the steel begins to stiffen under the hammer. Do not forge below 1,700 deg.F... Furnace Data
In order to give definite information concerning furnaces, fuels etc., the following data is quoted from a paper by Seth A. Moulton and W. H. Lyman before the Steel Heat Treaters Society in September, 1920. This considers a factory producing 30,0... Gas Consumption For Carburizing
Although the advantages offered by the gas-fired furnace for carburizing have been generally recognized in the past from points of view as close temperature regulation, decreased attendance, and greater convenience, very little information has been ... Gears
The material used for all gears on the Liberty engine was selected at the option of the manufacturer from the following standard S. A. E. steels, the composition of which are given in Table 12, TABLE 12.--COMPOSITION OF STEELS NOS. X-3,340 AND 6,1... Hardening
The forgings can be hardened by cooling in still air or quenching in oil or water from a temperature between 1,650 and 1,750 deg.F. The physical properties do not vary greatly when the carbon is within the range of composition given, or when the ... Hardening
Steel is hardened by quenching from above the upper critical. Apparently the quick cooling prevents the normal change back to definite and sizeable crystals of ferrite and cementite. Hardness is associated with this suppressed change. If the change ... Hardening Carbon Steel For Tools
For years the toolmaker had full sway in regard to make of steel wanted for shop tools, he generally made his own designs, hardened, tempered, ground and usually set up the machine where it was to be used and tested it. Most of us remember the to... Hardening High-speed Steel
In forging use coke for fuel in the forge. Heat steel slowly and thoroughly to a lemon heat. Do not forge at a lower heat. Do not let the steel cool below a bright cherry red while forging. After the tool is dressed, reheat to forging heat to remove... Hardening High-speed Steels
We will now take up the matter of hardening high-speed steels. The most ordinary tools used are for lathes and planers. The forging should be done at carbon-steel heat. Rough-grind while still hot and preheat to about carbon-steel hardening heat, th... Hardening Operation
Hardening a gear is accomplished as follows: The gear is taken from the furnace by the furnaceman and placed in the lower die, surrounding the centering jaws, as shown at H in Fig. 62 and C in Fig. 63. Air is then turned into the cylinder D, and th... Hardness Testing
The word hardness is used to express various properties of metals, and is measured in as many different ways. Scratch hardness is used by the geologist, who has constructed Moh's scale as follows: Talc has a hardness of 1 Rock Salt h... Heat Treatment Of Axles
Parts of this general type should be heat-treated to show the following minimum physical properties: Elastic limit, 115,000 lb. per square inch; elongation in 2 in., 16 per cent; reduction of area, 50 per cent; Brinell hardness, 277 to 321. The h... Heat Treatment Of Gear Blanks
This section is based on a paper read before the American Gear Manufacturers' Association at White Sulphur Springs, W. Va., Apr. 18, 1918. Great advancement has been made in the heat treating and hardening of gears. In this advancement the chemic... Heat Treatment Of Lathe Planer And Similar Tools
FIRE.--For these tools a good fire is one made of hard foundry coke, broken in small pieces, in an ordinary blacksmith forge with a few bricks laid over the top to form a hollow fire. The bricks should be thoroughly heated before tools are heated. H... Heat Treatment Of Milling Cutters Drills Reamers Etc
THE FIRE.--Gas and electric furnaces designed for high heats are now made for treating high-speed steels. We recommend them for treating all kinds of Blue Chip tools and particularly the above class. After tools reach a yellow heat in the forge fire... Heat Treatment Of Punches And Dies Shears Taps Etc
HEATING.--The degree to which tools of the above classes should be heated depends upon the shape, size and use for which they are intended. Generally, they should not be heated to quite as high a heat as lathe tools or milling cutters. They should h... Heat Treatment Of Steel
Heat treatment consists in heating and cooling metal at definite rates in order to change its physical condition. Many objects may be attained by correct heat treatment, but nothing much can be expected unless the man who directs the operations know... Heat-treating Department
The heat-treating department occupies an L-shaped building. The design is very practical, with the furnace and the floor on the same level so that there is no lifting of heavy pots. Fuel oil is used in all the furnaces and gives highly satisfactory... Heat-treating Equipment And Methods For Mass Production
The heat-treating department of the Brown-Lipe-Chapin Company, Syracuse, N. Y., runs day and night, and besides handling all the hardening of tools, parts of jigs, fixtures, special machines and appliances, carburizes and heat-treats every month bet... Heating
Although it is possible to work steels cold, to an extent depending upon their ductility, and although such operations are commonly performed, forging usually means working heated steel. Heating is therefore a vital part of the process. Heating s... Heating Of Manganese Steel
Another form of heat-treating furnace is that which is used for the heating of manganese and other alloy steels, which after having been brought to the proper heat are drawn from the furnace into an immediate quenching tank. With manganese steel in... Heavy Forging Practice
In heavy forging practice where the metal is being worked at a welding heat, the amount of flame that will issue from an open-front furnace is so great that a plain, sheet-steel front will neither afford sufficient protection nor stand up in servic... High Speed Steel
For centuries the secret art of making tool steel was handed down from father to son. The manufacture of tool steel is still an art which, by the aid of science, has lost much of its secrecy; yet tool steel is today made by practical men skilled as ... High-carbon Machinery Steel
The carbon content of this steel is above 30 points and is hardly ever above 60 points or 0.60 per cent. Annealing such steel is generally in quantity production and does not require the care that the other steels need because it is very largely a m... High-chromium Or Rust-proof Steel
High-chromium, or what is called stainless steel containing from 11 to 14 per cent chromium, was originally developed for cutlery purposes, but has in the past few years been used to a considerable extent for exhaust valves in airplane engines becau... Highly Stressed Parts
The highly stressed parts on the Liberty engine consisted of the connecting-rod bolt, the main-bearing bolt, the propeller-hub key, etc. The material used for parts of this type was selected at the option of the manufacturer from standard S. A. E. s... Hints For Tool Steel Users
Do not hesitate to ask for information from the maker as to the best steel to use for a given purpose, mentioning in as much detail as possible the use for which it is intended. Do not heat the steel to a higher degree than that fixed in the desc... Impact Tests
Impact tests are of considerable importance as an indication of how a metal will perform under shock. Some engineers think that the tensile test, which is one made under slow loading, should therefore be supplemented by another showing what will hap... Instructions For Working High-speed Steel
Owing to the wide variations in the composition of high-speed steels by various makers, it is always advisable to follow the directions of each when using his brand of steel. In the absence of specific directions the following general suggestions fr... Introduction Of Carbon
The matter to which these notes are primarily directed is the introduction of carbon into the case of the article to be hardened. In the first place the chances of success are increased by selecting as few brands of steel as practicable to cover the... Judging The Heat Of Steel
While the use of a pyrometer is of course the only way to have accurate knowledge as to the heat being used in either forging or hardening steels, a color chart will be of considerable assistance if carefully studied. These have been prepared by sev... Knowing What Takes Place
How are we to know if we have given a piece of steel the very best possible treatment? The best method is by microscopic examination of polished and etched sections, but this requires a certain expense for laboratory equipment and upkeep, which m... Lathe And Planer Tools
FORGING.--Gently warm the steel to remove any chill, is particularly desirable in the winter, then heat slowly and carefully to a scaling heat, that is a lemon heat (1,800 to 2,000 deg.F.), and forge uniformly. Reheat the tool for further forging di...