Nitrided or soft nitrided part with excellent wear resistance and pitting resistance, and nitriding and soft nitriding method

摘要

A nitrided part and soft nitrided part with excellent wear resistance and pitting resistance and a nitriding method and soft nitriding method are provided, specifically, a nitrided part or soft nitrided part made by a steel material comprising, by mass %, C: 0.05 to 0.3%, Si: 0.05 to 1.5%, Mn: 0.2 to 1.5%, P: 0.025% or less, S: 0.003 to 0.05%, Cr: 0.5 to 2.0%, Al: 0.01 to 0.05%, and N: 0.003 to 0.025% and having a balance of Fe and impurities, wherein, the surface layer comprises a compound layer containing iron, nitrogen, and carbon and a nitrogen diffusion layer positioned below the compound layer, the compound layer comprises an ε single phase, the ε single phase has a thickness of 8 to 30 μm and a Vicker's hardness of 680 HV or more, and the ε single phase has a volume ratio of pores of less than 10%.