CASE-HARDENED COMPONENT EXCELLENT IN WHOLE RANGE STRENGTH FROM STATIC STRENGTH TO HIGH CYCLE FATIGUE STRENGTH

摘要

PROBLEM TO BE SOLVED: To provide a case-hardened component which has improved strength in the whole range from a static strength to a high cycle fatigue strength.;SOLUTION: The case-hardened component 1 is formed by applying carburizing treatment to a steel containing, by mass%, 0.10-0.30% C, 0.50-1.50% Si, 0.30-1.00% Mn, ≤0.035% P, ≤0.035% S, 0.15-1.25% Cr, 0.30-0.80% Mo, 0.020-0.150% Al, 0.0030-0.0200% N, 0.0005-0.0050% B, 0.005-0.200% Ti, wherein Si(%)+Mo(%)+30B(%)≥1.10 is satisfied, and the balance Fe with inevitable impurities. The maximum depth (d) of an abnormal carburized case 12 in the surface of a carburized case 11, is ≤15 μm and the area ratio which is occupied by the abnormal carburized case 12 in the cross-sectional surface from the maximum depth position D to the surface 100, is ≥70%.;COPYRIGHT: (C)2010,JPO&INPIT