PRODUCTION OF CARBURIZED AND CASE HARDENED STEEL MATERIAL HAVING DELAYED FRACTURE RESISTANCE

摘要

PURPOSE: To easily produce a carburized and case hardened steel material showing superior delayed fracture resistance and having sufficiently satisfactory mechanical properties. ;CONSTITUTION: A steel stock which has a composition consisting of 0.30-0.45% C, ≤1.00% Si, ≤2.00% Mn, ≤3.50% Ni, ≤3.00% Cr, ≤3.00% Mo, and the balance Fe with inevitable impurities or further containing one or more kinds among ≤0.0050% Nb, ≤0.30% V, ≤0.30% Pb, ≤0.0100% Ca, and 0.0005-0.0050% B is carburized and quenched and is then subjected to tempering treatment at 400-600°C and to induction hardening, by which the hardness of the carburized layer softened by tempering can be restored.;COPYRIGHT: (C)1993,JPO&Japio