中文摘要：

采用Gleeble-1500热／力模拟压缩试验机研究了X70管线钢在管件制造热过程中的形变规律。结果表明：X70管线钢在管件制造热过程中存在动态回复型和动态再结晶型两种真应力-应变曲线。在高的形变温度和低的应变速率条件下，发生动态再结晶，其热变形方程式为ε=4×10^-8σp^10.27exp（-Q/RT）；峰值应力σp、峰值应变εp与Zener-Hollomon因子Z的关系分别为lnσp=1．869＋0．093lnZ、lnZ、lnεp=-1.291＋0．021lnZ；动态再结晶体积分数Xd=1-exp[-1．51（ε／εp-0．83）^1.22]。

英文摘要：

The deformation law in fitting-manufacture thermal process of an X70 grade pipeline steel was investigated using a Gleeble-1500 tester. There were two kinds of stress-strain curves of both dynamic recovery and dynamic recrystallization in thermal deformation process. Under the condition of high temperature and low strain rate, dynamic recrystallization occurred. The thermal deformation equation was ε= 4 × 10^-8σp^10.27 exp（-Q/RT） and relations between σp of εp and Z were In σp = 1. 869＋0. 093lnZ and ln εp = - 1. 291＋0. 021 lnZ respectively. The volume fraction of dynamic recrystallization was Xd = 1 - exp[- 1.51 （ε/εp - 0. 83）^ 1. 22 ].