The delayed excellent long life steel and manufacturing method thereof for bearing on fracture properties

摘要

PROBLEM TO BE SOLVED: To produce steel for a bearing having a long service life and excellent in delayed fracture resistance and to provide a method for producing it. ;SOLUTION: This steel for a bearing having a long service life is the one having a compsn. contg., by weight, 0.65 to 1.2% C, 0.05 to 0.50% Si, 0.2 to 2.0% Mn, 0.05 to 0.20% Ti, 0.005 to 0.050% Al, ≤0.0120% N, ≤10 ppm O, and the balance Fe with inevitable impurities, furthermore contg. one or ≥ two kinds among 0.1 to 2.0% Ni, 0.20 to 2.0% Cr and 0.05 to 1.0% Mo, in which Ti carbides and Ti carbonitricles of ≤70 nm size are finely dispersed into the steel, and having excellent delayed fracture resistance by a thrust life test machine shown by the fig.;COPYRIGHT: (C)1999,JPO