METHOD FOR QUENCHING OF STEEL MEMBER, QUENCHED STEEL MEMBER, AND AGENT FOR PROTECTING QUENCHED SURFACE

摘要

[PROBLEMS] To provide a technique for hardening of the surface of a member for a mechanical structure, which can provide superior mechanical strength including bearing strength, wear resistance and bending fatigue strength compared to a conventional technique. [MEANS FOR SOLVING PROBLEMS] A quenched steel member comprising a steel member, a hard nitride layer formed on the surface of the steel member, and an inorganic compound layer comprising at least one oxide of a metal selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, W, Mo and Al formed on the hard nitride layer.