Abstract: The test steel 305B (/%: 0. 048C, 3. 32Si, 1. 34Mn, 19. 46Cr, 13. 32Ni, 0. 46Nb), steel 304 (/%: 0.050C, 0. 30Si, 0.90Mn, 18. 05Cr, 9. 23Ni) and steel 310S (/%: 0. 051C, 0.44Si, 1. 17Mn, 25. 36Cr, 21.32Ni) are melted by a 200 kg vacuum induction furnace. The high-temperature mechanical properties at 500 ~ 1 000 °C of test steels, and quenched structure of steel 305B are studied by using Gleeble-3800 thermo-simulation machine, optical microscope and transmission electron microscope, and the equilibrium phase diagram with 15% -25% Cr for steel 305B is obtained by using Thermo-calc software. Results show that at 500 ~ 1 000 °C the yield strength of steel 305 B (261 MPa at 500℃，45 MPa at 1 000 ℃) is high than that of steel 304 and steel 310S, and the tensile strength of steel 305 B ( 536 MPa at 500 °C , 75 MPa at 1 000 ℃ ) is close to that of steel 310S and far more higher than that of steel 304, the NbC precipitate phase in steel 305 B leads to it has higher strength at elevated temperature ； the reduction of area of steel 305 B at elevated temperature is higher than that of steel 310S and lower than that of steel 304.

摘要： 试验305B钢(/%:0.048C、3.32Si、1.34Mn、19.46Cr、13.32Ni、0.46Nb),304钢(/%:0,050C、0.30Si、0.90Mn、18.05Cr、9.23Ni)和310S钢(/%:0.051C、0.44Si、1.17Mn、25.36Cr、21.32Ni)由200 kg真空感应炉熔炼。通过Gleeble-3800热模拟试验机、光学显微镜和透射电子显微镜研究了试验钢的500～1 000℃的高温力学性能和水冷后的组织,以及利用Thermo-calc软件得出305B钢在15%～25%Cr内的平衡相图。结果表明,在500～1 000℃305B钢屈服强度(500℃-261 MPa,1 000℃-45 MPa)高于304钢和310S钢,305B钢抗拉强度(500℃-536MPa,1 000℃-76 MPa)接近310S钢,但远高于304钢,305B钢NbC析出相使该钢具有高的高温强度;305B钢的高温断面收缩率高于310S钢,低于304钢。