| This worthy and learned prelate, the bishop of St. David's in Wales, having in the former reign, as well as since the accession of Mary, been remarkably zealous to promoting the reformed doctrines, and exploding the errors of popish idolatry, w... Read more of Dr Robert Farrar at Martyrs.ca |  Informational.caPrivacy |
Steel MakingPickling The ForgingsThe forgings were then pickled in a hot solution of either ni... Hardness Testing The word hardness is used to express various properties of me... Mushet And Bessemer That Mushet was "used" by Ebbw Vale against Bessemer is, perh... High-chromium Or Rust-proof Steel High-chromium, or what is called stainless steel containing f... Sulphur SULPHUR is another element (symbol S) which is always found i... Lathe And Planer Tools FORGING.--Gently warm the steel to remove any chill, is parti... Heat Treatment Of Milling Cutters Drills Reamers Etc THE FIRE.--Gas and electric furnaces designed for high heats ... Temperatures To Use As soon as the temperature of the steel reaches 100 deg.C. (... Hardening Steel is hardened by quenching from above the upper critical.... Phosphorus Phosphorus is one of the impurities in steel, and it has been... Alloying Elements Commercial steels of even the simplest types are therefore p... Hardening Carbon Steel For Tools For years the toolmaker had full sway in regard to make of st... Case-hardening Treatments For Various Steels Plain water, salt water and linseed oil are the three most co... Composition And Properties Of Steel It is a remarkable fact that one can look through a dozen tex... Steel Can Be Worked Cold As noted above, steel can be worked cold, as in the case of ... Process Of Carburizing Carburizing imparts a shell of high-carbon content to a low-... Correction For Cold-junction Errors The voltage generated by a thermo-couple of an electric pyrom... Leeds And Northrup Optical Pyrometer The principles of this very popular method of measuring tempe... Manganese Manganese adds considerably to the tensile strength of steel,... William Kelly's Air-boiling Process An account of Bessemer's address to the British Association w... |
Annealing WorkCategory: HEAT TREATMENT OF STEEL With the exception of several of the higher types of alloy steels, where the percentages of special elements run quite high, which causes a slight air-hardening action, the carburizing steels are soft enough for machining when air cooled from any temperature, including the finishing temperature at the hammer. This condition has led many drop-forge and manufacturing concerns to consider annealing as an unnecessary operation and expense. In many cases the drop forging has only been heated to a low temperature, often just until the piece showed color, to relieve the so-called hammer strains. While this has been only a compromise it has been better than no reheating at all, although it has not properly refined the grain, which is necessary for good machining conditions. Annealing is heating to a temperature slightly above the highest critical point and cooling slowly either in the air or in the furnace. Annealing is done to accomplish two purposes: (1) to relieve mechanical strains and (2) to soften and produce a maximum refinement of grain. Next: Process Of Carburizing Previous: Heat Treatment Of Gear Blanks
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