关键词: Nb-V微合金化, Si-Mn-Cr-Mo贝氏体钢轨钢, 硅, 组织, 力学性能,

Abstract: The effects of silicon content on microstructure and mechanical properties of the test 1 250 MPa grade Nb- V microaUoyed Si-Mn-Cr-Mo bainite rail steel (/% ：0.25 C,0.38～1.56 Si,1.69～1.76 Mn,1.34～1.37 Cr,0.32～0. 33 Mo,0.034 ～0.036 Nb,0. 11 ～0. 12 V) are studied. The test results show that by test steel air cooling after hot-rolling, with the increase of silicon content, the ferrite + pearlite phase transformation test steel is suppressed, and the content of bainite and martensite in the room temperature structure increases to afiect the strength and hardness of steel. With silicon content increasing from 0.38% to 1.56% , the test steel % yield strength increases from 846 MPa to 903 MPa, the tensile strength increases from 1 280 MPa to 1 355 MPa, and the HBW hardness value increases from 353 to 411.