Transactions of the American Society for Steel Treating, Volume 4

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American Society for Steel Treating., 1923

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Page 400 - The quenching temperatures given are at the lowest temperature range consistent with highest quality tools; deviations from it are not recommended, but may be practical for diverse reasons. Quenching. — Water is the universal quenching medium, and by varying its temperature and manner of application for the abstraction of heat, almost any degree of variation of structural conditions of the tool steel can be obtained. There are, however, special cases where oil may be a more suitable quenching medium.
Page 22 - Full information and application blanks may be obtained from the United States Civil Service Commission, Washington, DC, or the secretary of the board of US civil-service examiners at the post office or customhouse in any city.
Page 399 - ... highest quality performance of tools for general purposes only. For specific applications where special structural requirements seem to be necessary, deviation from the recommended practice must be left to the judgment of the individual heat treater or metallurgist. 2. Normalizing. — A normalizing treatment for all tool steels is recommended to obtain a uniform and refined grain structure, which enables the operator to predict the behavior and performance of the steel tool during heating and...
Page 264 - It would seem as if the methods used to date for the elucidation of this complex problem have yielded all they are capable of yielding and that further straining of these methods will only serve to confuse the issue, a point having been reached when this juggling, no matter how skillfully done, with allotropy, solid solution, and strains, is causing weariness without advancing the solution of the problem.
Page 404 - Cooling in air should not be permitted, since air cooling from the annealing temperature is apt to result in partial hardening of the tool. Heating for Hardening. — It is the customary practice to always preheat for hardening in an open furnace, since preheating in a salt bath causes the salt to adhere to the tool, and the subsequent high temperature treatment causes unusual corroding from the adhering salt. Even preheating in lead is objectionable from small quantities of adhering lead. There...
Page 270 - ... the weaker constituent. Just as slip is opposed at the grain boundaries of a pure metal by the change in orientation, it may be opposed to a still greater extent if the material at the grain boundary possesses in addition to its different orientation a specifically greater hardness. The most familiar example of this is the reinforcing effect of the pearlite constituent in hypoeutectoid steels.
Page 468 - Carbon not over 0.06 of one per cent Manganese not over 0.15 of one per cent Phosphorus not over 0.04 of one per cent...
Page 401 - Carbon Content 0.81 to 0.95 Per Cent. — Hot and cold sets, chisels, dies, shear blades, mining drills, smiths' tools, set hammers, swages, flatteners. Carbon Content 0.96 to 1.10 Per Cent. — Small cold chisels, hot sets, small shear blades, large pinchers, large taps, granite drills, trimming dies, turning tools, planer tools, drills, cutters, slotting and milling tools, mill picks, circular cutters, small shear blades, threading dies. Carbon Content 1.11 to 1.25 Per Cent. — Small cutters,...
Page 401 - ... brass and copper alloys. Scraper and cutting tools for soft metals and micarta. Drawing mandrels, drawing dies, bone-cutting tools, hammer-faces, steel engraving tools, wood-carving tools, cutting tools for iron and steel, hand tools, threading dies for brass. Temperature, 400 to 500° F.
Page 280 - FORMATION OF CEMENTITE FROM MARTENSITE As mentioned above, no substantial diffusion of atoms is necessary in the transformation of face-centered iron to the bodycentered lattice. Since carbon is very much less soluble in Alpha than in Gamma iron, there is a strong force toward precipitation of carbide as soon as the iron transformation has taken place. In order for cementite to form, however, the carbon atoms must diffuse. Carbon can diffuse slowly at room temperature in the iron lattice and does...

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