热压缩变形参数对海底用X70管线钢再结晶行为的影响

Effects of Hot Compression Deformation Parameters on Recrystallization Behavior of X70 Pipeline Steel Used in Submarine

采用热模拟试验机研究了应变速率为1s-1时变形温度、变形量和变形后保温时间对海底用X70管线钢再结晶行为的影响。结果表明:在变形量为25%的条件下,试验钢发生动态再结晶的变形温度为1 0001 020℃,奥氏体晶粒可细化到33μm左右;在变形温度为980℃的条件下,发生动态再结晶的变形量为25%30%,当变形量达到30%时,再结晶基本完成,晶粒尺寸随变形量增大而减小;在变形温度为980℃、变形量为25%的条件下变形完成保温5s后,试验钢开始发生静态再结晶,保温30s后静态再结晶基本完成,此时晶粒尺寸最小,为41μm。

Effects of deformation temperature,deformation and holding time after deformation on recrystallization behavior of X70 pipeline steel used in submarine were studied by thermal simulator.The results show that when deformation was 25%,dynamic recrystallization temperature of the tested steel was 1 000-1 020 ℃,austenite grain size could be refined to 33μm.Under the condition of deformation temperatue of 980 ℃,dynamic recrystallization happened at deformation range of 25%-30%,dynamic recrystallization completed basically when deformation was 30%.Grain size decreased with the increase of deformation.When deformation temperature was980 ℃,deformation was 25% and holding time was 5s,tested steels started to static recrystallization,the static recrystallization completed basically after holding 30 s.At the moment,austenite grain size was minimum and up to41μm.