PURPOSE: To improve the rolling fatigue service life properties in the bearing steel by specifying the content of C, Si, Mn, Cr, W, etc., in a steel.
CONSTITUTION: The compsn. of a bearing steel is formed from, by weight, 0.6 to 1.2% C, 0.50 to 2.00% Si, 0.15 to 2.50% Mn, 0.50 to 3.00% Cr, 0.005 to 1.00% W, ≤0.0020% O and the balance Fe with inevitable impurities. If required, one or more kinds of 0.05 to 0.50% V and 0.05 to 0.50% Nb or moreover one or more kinds of 0.1 to 1.0% Ni and 0.05 to 0.50% Cu are incorporated thereto. The heat treatment to the steel can be executed in the same way as that to a usual bearing steel, and its quench-and-temper hardness is not inferior to that of a usual bearing steel. Since the steel has high content of carbides and they are stable even at a high temp., its wear resistance is made excellent and its application can be expected even to a rolling bearing with high bearing pressure.
AMANO KENICHI
TABATA NOBUHISA
NAKANO SHOZABURO
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