Abstract: With using Gleeble-3500 thermal simulator the single pass hot compression deformation and structure evolution of 20 mm hot-rolled plate of 700 MPa pipeline steel (/%: 0.07C, 0.90Si, 0.60Mn, 0.008P, 0.002S, 0.30Ni, 0.10Cr, 0.12Mo, 0.06V, 0.03Nb, 0.28Cu, 0.04Alt, 0.0060N) with strain rate 0.01~1s^-1 at 850~1250°C have been studied to get single pass real stress-strain curves, hot compression dynamic recrystallization diagram and relation between dynamic recrystallization initial time and deformation temperature (RTT) curves. Research results show that deformation temperature and strain rate make certain of initial recrystallization, the 700 MPa pipe line steel easily occurs dynamic recrystallization with strain rate 0.01~1s^-1 at 1100~1250°C.the recrystallization mechanism is hot compression causing the original grain crushing and the new grain boundary migrating to prompt formation of new crystal nucleus.

摘要： 利用 Gleeble-3500型热模拟机，研究700MPa 管线钢(/%：0.07C,0.90Si,0.60Mn,0.008P,0.002S, 0.30Ni,0.10Cr,0.12Mo,0.06V，0.03Nb,0.28Cu,0.04Alt,0.0060N) 20mm热轧板在850~1250℃ 和应变速率0.01~1s^-1下单道次热压缩变形及组织演变,得出单道次压缩变形真应力-真应变曲线，热压缩再结晶动态图和动态再结晶开始时间与变形温度关系(RTT)曲线。研究结果表明，发生再结晶由变形温度和应变速率共同决定，该700MPa管线钢在温度1100~1250℃和应变速率0.01~1s^-1下压缩变形时容易发生再结晶。再结晶发生机制是热压缩应变，使得原始晶粒破碎、新晶界产生迁移促使新晶核生成。

关键词: 700MPa管线钢, 20mm热轧板, 再结晶, 热压缩