The Effect

: The Working Of Steel

The heating at 1,600 deg.F. gives the first heat treatment

which refines the core, which under the former high heat (1,700 deg.F.)

was rendered coarsely crystalline. All the gears, including the

scrap gears, are quenched direct from the pot in this manner.

The gears then go to the reheating furnaces, situated in front of

a battery of Gleason quenching machines. These furnaces accommodate

from 12 to 16 crown gears. The carbon-steel gears are heated in a

reducing atmosphere to about 1,425 deg.F. (depending on the carbon

content) placed in the dies in the Gleason quenching machine, and

quenched between dies in mineral oil at less than 100 deg.F. The test

gear receives exactly the same treatment as the others and is then

broken, giving a record of the condition of both case and core.