Steel for cold forging/nitriding, steel material for cold forging/nitriding, and cold-forged/nitrided component

摘要

A steel for cold forging/nitriding has, by mass percent, C: 0.01 to 0.15%, Si≤0.35%, Mn: 0.10 to 0.90%, P≤0.030%, S≤0.030%, Cr: 0.50 to 2.0%, V: 0.10 to 0.50%, Al: 0.01 to 0.10%, N≤0.0080%, and O≤0.0030%, further according to need a specific amount of one or more elements selected from Mo, Cu, Ni, Ti, Nb, Zr, Pb, Ca, Bi, Te, Se and Sb, with the balance being Fe and impurities, and further satisfying the conditions of [399×C+26×Si+123×Mn+30×Cr+32×Mo+19×V≤160], [20≤(669.3×log_eC−1959.6×log_eN−6983.3)×(0.067×Mo+0.147×V)≤80], [140×Cr+125×Al+235×V≥160] and [90≤511×C+33×Mn+56×Cu+15×Ni+36×Cr+5×Mo+134×V≤170] are excellent in cold forgeability and machinability after cold forging.