杨维宇, 何建中, 梁正伟, et al. Effect of Tempering Process on Microstructure and Properties of Hot rolled U20Mn2SiCrNiMo Bainitic Rail Steel[J]. Special Steel, 2021, 42(6): 68-71.
杨维宇, 何建中, 梁正伟, et al. Effect of Tempering Process on Microstructure and Properties of Hot rolled U20Mn2SiCrNiMo Bainitic Rail Steel[J]. Special Steel, 2021, 42(6): 68-71.DOI:
The flowsheet process of U20Mn2SiCrNiMo bainitic rail steel is 150 t BOF-LF-VD-280 mm×380 mm cast bloom-rolling
finishing at 930~980℃
air cooling -340℃ 4 h
air cooling
double tempeing.The microstructure of hotrolled(end rolling at 930~980℃ air cooling)and tempered(320 ℃once-and double-tempering)of U20Mn2SiCrNiMo steel is composed of bainite
martensite and retained austenite.Mechenical properties test results show that the optimum tempering process of U20Mn2SiCrNiMo steel rail is 320℃4 h air cooling+320℃4 hair cooling
double tempeing
its yield strength is 1242 MPa
tensile strength 1393 MPa
HBW hardness 417
elongation 15.0%
reduction of area 60%
impact absorption work K
u2
is 98 J
and longitudinal residual stress of rail bottom +180 MPa.