Production manner null of cold malleability and the steel and the cold hammering component which for cold hammering are superior in fatigue

摘要

PROBLEM TO BE SOLVED: To inexpensively provide a machine structural member having an excellent cold forgeability and high-grade surface by means of cold working such as cold forging. ;SOLUTION: The cold forging steel, excellent in cold forgeability and fatigue strength, has a composition consisting of, by weight, 0.05-0.25% C, 0.35-0.60% Si, 0.20-1.30% Mn, 0.15-0.60% Cr, further one or more kinds among 0.030-0.100% S, 0.005-0.040% Te, 0.03-0.30% Pb, 0.03-0.20% Bi, and 0.0005-0.0050% Ca, and the balance essentially Fe and satisfying, by wt.%, 19≤85(C)+9(Si)+3(Mn)+5(Cr)≤25 and 100(C)+3(Si)+3(Mn)-9(Cr)+100(S)-20(Te)≤23.;COPYRIGHT: (C)1998,JPO