Annealing Work

: The Working 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 opera
ion 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


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.