一种新型高淬透性Ni-Cr-Mo-B钢的热变形本构分析

Hot Deformation Constitutive Analysis of a Novel Ni-Cr-Mo-B Steel with High Hardenability

基于Gleeble单道次热压缩实验并结合OM表征手段及回归方法,研究了一种新型高淬透性Ni-Cr-Mo-B特厚板钢在850～1 150℃和0. 01～10 s-1热变形参数下的热变形行为。结果表明,Ni-Cr-Mo-B钢在热变形过程中流变应力随变形温度的升高而减小,随应变速率的增加而增大。建立的典型应变补偿Arrhenius型本构方程可用于粗略预测Ni-Cr-Mo-B钢的流变行为。考虑到应变速率、变形热对变形过程的影响,提出修正应变补偿Arrhenius型本构方程,其统计学参量Rc=0. 994 68、AARE=3. 69%、RMSE=6. 44 MPa、NMBE=1. 25%,相对误差大部分(94. 87%)在±10%之内,表明该方程具有极高的流变应力预测精度。

Hot deformation behavior of a novel Ni-Cr-Mo-B ultra-heavy plate steel with high hardenability at 850-1 150 ℃ and the strain rates of 0.01 to 10s^-1 was studied by means of single pass Gleeble hot compression tests,optical microscopy and regression method.The results revealed that the rheological stress of Ni-Cr-Mo-B steel decreased with the increasing deformation temperature and increased with the rising strain rate du-ring hot compression.The classic strain-compensation Arrhenius-type constitutive equation established in this study could roughly predict the rheological behavior of Ni-Cr-Mo-B steel.Furthermore,a revised strain-compensation Arrhenius-type constitutive equation was proposed by taking the influence of strain rate and deformation heat on the deformation process into consideration.The statistical parameters of the revised equation were as follow,R c=0.994 68,AARE =3.69%,RMSE =6.44 MPa,NMBE =1.25%,-10%≤δ≤10%,which means that the revised equation could predict the rheological stress more accurately.