Abstract: S35VN high carbon martensitic stainless steel prepared by powder metallurgy method is widely used as tool materials, and the type of its matrix microstructure and the carbides distributed in the matrix directly affect the comprehensive properties of the steel. The changes of microstructure and mechanical properties of the S35VN steel under different final rolling temperatures during hot rolling were studied by thermal dilatometer, Vickers hardness tester, X-ray diffractometer and scanning electron microscopy. The results show that at the final rolling temperature of 850 ℃, the microstructure is fine carbides dispersed in the ferrite matrix, and the material has good comprehensive mechanical properties, with the tensile strength and the elongation being 1003.5 MPa and 2.78%, respectively. With the increase of the final rolling temperature, the matrix structure of the material changes from ferrite to martensite, and the carbides become larger in size and less in quantity, and the strength of the material increases significantly but the plasticity deteriorates. When the final rolling temperature is further raised to 950 ℃, the material strength is further improved but the plasticity is poor.

Key words: high carbon stainless steel, final rolling temperature, microstructure, mechanical properties