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通过Gleeble-1500D型热模拟机对REⅡ稀土重轨钢进行应变速率为5 s-1、变形量均为25%的双道次热压缩模拟试验,分别测定820,850,880,1000℃下的真应力-真应变曲线,采用后插法计算奥氏体等温变形后道次间隙时间1～1200 s内的软化率,研究REⅡ稀土重轨钢的静态再结晶规律。结果显示:当变形温度为>1000℃时,REⅡ重轨钢完成静态再结晶弛豫时间<90 s;当变形温度<820℃时,静态再结晶很难进行,即使弛豫时间延长至1000 s,再结晶百分数也只有38.8%;当变形温度为850和880℃时,再结晶过程会出现析出现象,对抑制静态再结晶的进行有影响,导致软化率曲线上出现了平台。
Through the Gleeble-1500D thermal simulator, REⅡ rare earth heavy rail steel was subjected to two-pass thermo-compression simulations with a strain rate of 5 s-1 and a deformation of 25% respectively. The true stress at 820, 850, Strain curve, the post-interpolation method is used to calculate the softening ratio within 1 ~ 1200 s after austenite deformation during isotropic deformation, and the static recrystallization rule of REⅡ RE rail is studied. The results show that the static recrystallization relaxation time of REⅡ heavy rail steel is less than 90 s when the deformation temperature is> 1000 ℃. When the deformation temperature is less than 820 ℃, static recrystallization is very difficult. Even when the relaxation time is extended to 1000 s , And the percentage of recrystallization is only 38.8%. When the deformation temperature is 850 and 880 ℃, precipitation will occur during the recrystallization process, which has an impact on the suppression of static recrystallization, resulting in a platform on the softening rate curve.