Production manner null of the material for the bearing which is superior in convolution fatigue

摘要

PURPOSE:To manufacture a raw material for bearing having excellent service life to rolling fatigue by continuously casting molten steel containing the specific wt.% of C, Si, Mn, Cr and Mo and executing the specific draft of squeezing work near crater end, which solidification in inner part of a cast billet is completed, and hot-working. CONSTITUTION:The molten steel containing wt.% of 0.60-1.50% C, 0.15-2.00% Si, 0.15-2.50% Mn, 0.05-1.00% Cr, 0.50-1.50% Mo and the balance of Fe and inevitable impurities, is continuously cast. The squeezing work is executed near the crater end, where the solidification in the inner part of cast billet is completed, at =5% draft and successively, the hot-rolling is executed. In the molten steel, further, one or more kinds among 0.05-0.50% V, 0.05-0.50% Nb, 0.05-0.50% W, 0.10-2.00% Ni and 0.05-1.00% Cu, are incorporated. By this method, necessity for executing homogenized annealing at high temp. for long time, can be eliminated.