Stainless steel surface composite infiltrated layer and preparation method and application thereof

The invention discloses a stainless steel surface composite infiltrated layer and a preparation method and application thereof. The stainless steel surface composite infiltrated layer comprises a surface CrN + Cr2N layer and a nitrided austenite diffusion layer. According to the method, gradient ion nitriding treatment is combined with chromizing treatment, a novel stainless steel surface composite nitriding layer is obtained, compared with a traditional nitriding and chromizing method, the composite nitriding layer is of a complete and compact CrN + Cr2N layer and nitrided austenite diffusion layer gradient nitriding layer structure, the corrosion resistance and wear resistance of the nitriding layer are more excellent, and the service life of the composite nitriding layer is prolonged. And the infiltrated layer and the matrix are high in bonding strength and good in toughness. Meanwhile, the preparation method of the composite infiltrated layer is easy to operate and high in infiltrating speed, a large-thic