| 摘要 |
The purpose of the present invention is to provide a technique for producing a thicker compound layer composed primarily of a γ' phase, even when the customary duration of gas nitriding treatment is employed; the fatigue strength can be improved by carrying out film thickening; and a nitriding-treated member having improved wear resistance while being endowed with higher fatigue strength than in the prior art is possible. Provided are a nitride steel member having an iron nitride compound layer formed on the surface of a steel member comprising a steel component that gives rise to a primarily γ' phase compound layer, wherein the primarily γ' phase-based compound layer in which the proportion in which the γ' phase is present, when this value is expressed as a ratio defined by Vγ'/(Vγ' + Vε), where Vγ' and Vε denote the volume proportions of the γ' phase and the ε phase present in the iron nitride compound layer, is 0.5 or greater has a thickness of 13 μm-30 μm; and the value of the thickness of the compound layer following gas nitriding treatment, represented by the CLT of the iron nitride compound layer, satisfies the relationship CLT ÷ DLT ≥ 0.04. where DLT represents the value of the practical hardening depth of the nitrided diffusion layer subsequent to gas nitriding treatment; and a method for manufacturing the same. |
