: HEAT TREATMENT OF STEEL
: 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.