两种高等级管线钢的奥氏体热变形行为

Hot Deformation of Austenite for Two High Grade Pipeline Steels

利用MMS300热模拟试验机在温度为850~1 150℃,应变速率为5 s-1,道次间隔时间为1~400 s的条件下进行了X80及X100管线钢双道次压缩变形试验,测定了不同间隔时间、不同变形温度条件下的软化率。研究结果表明：当道次间隔时间相同时,随变形温度升高,X80及X100管线钢静态再结晶分数均增加,再结晶进程加快。X80及X100的静态再结晶激活能分别为308.7和341.8 kJ/mol。采用Avrami方程获得了X80及X100试验钢奥氏体静态再结晶动力学方程。

The hot deformation behaviors of X80 and X100 pipeline steels were investigated through double-hit compression experiments using MMS300 thermal-mechanical similar within the temperature range of 850-1 150 ℃,the strain rate of 5 s-1 and the pass interival range of 1-400 s,the softening fraction at different pass interval and deformation temperature was determined and analyzed.The results show that when pass intervals is the same,as deformation temperature increase,the volume fraction of static recrystallization of X80 and X100 pipeline steels increase and the recrystallization process is enhanced.Activation energy of austenite static recrystallization of X80 and X100 is 308.7 and 341.8 kJ/mol,respectively.The kinetic equation of static recrystallization of X80 and X100 pipeline steels by Avrami equation was obtained.