Research on gas nitriding process of 25Cr2MoVA steel

25Cr2MoVA steel treated by gas nitriding and the nitrided layer was characterized by optical microscope,microhardness test,X-ray diffraction and wear test.The results showed that the γ' single-phase compound layer could be obtained via gas nitriding method.At the same time,the surface hardness of the nitriding layer was enhanced and the microhardness gradient across the interface was flattened.Wear test demonstrated that the sample nitrided at 540 ℃ exhibited excellent wear resistance.