摘要
Effects of lanthanum（La） as micro-alloying element on the hot deformation behaviour of the high strength Mn-Cr-Mo bainitic rail steel were investigated under a range of deformation conditions. The results indicate that La increases the flow stress by 10-30 MPa through strengthening nanoscale strain induced precipitation（SIP） θ-（Fe,La）3 C during hot deformation. The hot deformation activation energy increases by 10-40 kJ/mol due to the ＂Zener effect＂ of SIP and the dynamic recrystallization（DRX） is retarded due to the competitive behaviour between SIP and DRX. Bainite plates in the DRX domain can be refined by adding La, resulting in the improvement of hot workability. The DRX domain with peak power dissipation efficiency of 52% is determined to be the optimal processing region for Mn-Cr-Mo-La bainitic rail steel.
Effects of lanthanum（La） as micro-alloying element on the hot deformation behaviour of the high strength Mn-Cr-Mo bainitic rail steel were investigated under a range of deformation conditions. The results indicate that La increases the flow stress by 10-30 MPa through strengthening nanoscale strain induced precipitation（SIP） θ-（Fe,La）3 C during hot deformation. The hot deformation activation energy increases by 10-40 kJ/mol due to the ＂Zener effect＂ of SIP and the dynamic recrystallization（DRX） is retarded due to the competitive behaviour between SIP and DRX. Bainite plates in the DRX domain can be refined by adding La, resulting in the improvement of hot workability. The DRX domain with peak power dissipation efficiency of 52% is determined to be the optimal processing region for Mn-Cr-Mo-La bainitic rail steel.
基金
supported by the National Natural Science Foundation of China(51461034)
