Effects of contents of Nb and C on hot deformation behaviors of
high Nb X80 pipeline steels
(1. School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, China;
2. College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004, China;
3. Shagang Group Corpoation, Zhangjiagang 215625, China)
2. College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004, China;
3. Shagang Group Corpoation, Zhangjiagang 215625, China)
Abstract: The behavior of the flow deformation and the effects of contents of Nb and C on deformation behaviors of high Nb X80 pipeline steels during hot compression deformation were studied by thermal simulation test. The content of solid solution Nb was quantificationally studied during the reheating and hot deformation process, and the effects of change of solid solution Nb in steels on hot deformation behaviors were discussed. The results show that the contents of Nb and C have great effects on the flow stress behaviors of high Nb X80 pipeline steels. When the C content in steels is constant, the recrystallization activation energy increases from 387 to 481 kJ/mol with increasing the Nb from 0.082% to 0.13% (mass fraction). However, the effect of Nb is correlative to the C content, i.e. w(Nb)/w(C). When w(Nb)/w(C) decreases from 3.61 to 2.18, the recrystallization activation energy decreases from 481 to 434 kJ/mol.
Key words: X80 pipeline steel; hot deformation; solid solution Nb; deformation activation energy