热连轧带钢温度场有限元分析和平均流变应力的预测

Finite Analysis of Temperature Field and Prediction of Mean Flow Stress during Multi-Pass Hot Strip Rolling

通过热连轧带钢温度场的有限元分析以及带钢热连轧过程的再结晶动力学和应变累积的研究 ,建立了精轧过程平均流变应力模型 :静态再结晶平均流变应力σs=k1 exp{ 0 .12 6 - 1.75 [C]+0 .5 94 [C]2 +(2 85 1+2 96 8[C]- 112 0 [C]2 ) T}ε0 .2 1 ε· 0 .1 3,其中T 再结晶温度 K ,ε 应变 ,ε· 应变速率 s- 1 ,k1 系数 ;动态再结晶平均流变应力σD =9.8σs(1-Xdyn) +1.14σss Xdyn,其中Xdyn 动态再结晶率 ,σss 动态再结晶进入稳态时应力。X4 6级管线钢 (% :0 .0 7C 0 .97Mn 0 .33Si 0 .0 18Nb)

The mean flow stress model in finish rolling has been established by finite-element analysis of temperature field during multi-pass strip hot rolling and study on recrystallization dynamics and strain accumulation in strip continuous rolling. The mean flow stress for static recrystallization σs = k1 exp｛0.126-1.75[C]+0.594[C]2+(2 851+2 968[C]-1 120[C]/T｝ε0.21ε·0.13, where T- recrystallization temperature/K, ε- strain, ε·- strain rate/s-1, k1- coefficient and the mean flow stress for dynamic recrystallization σD = 9.8σs(1-Xdyn)+1.14σssXdyn, where Xdyn- dynamic recrystallization ratio, σss- stress for dynamic recrystallization at stable state. The predicted data of rolling force by the model conform with the measured data of X46 grade steel 0.07C-0.97Mn-0.33Si-0.018Nb for pipe line during commercial rolling of strip.