特大型支承辊用Cr4合金钢的热变形行为及热加工图  

Hot deformation behavior and processing map of Cr4 steel for heavy back-up roll

作　　者：陈学文[1] 张亚东[1] 陈天安 王纳纳[1] 

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]江铃控股有限公司,江西南昌330000

出　　处：《金属热处理》2017年第12期29-34,共6页Heat Treatment of Metals

基　　金：国家自然科学基金(51575162)

摘　　要：采用Gleeble-1500热模拟实验机在温度为700~1200℃,应变速率为0.002~5 s^(-1)、最大变形量为55%条件下对特大型支承辊Cr4合金钢进行热压缩试验,研究了该合金的热变形行为及热加工特征,建立了Cr4合金钢在试验条件下的热加工图。结果表明:在其他变形参数恒定时,Cr4合金钢的热变形真应力随应变速率的升高而逐渐变大,随变形温度的提高而急剧降低;在变形温度为750~900℃,应变速率为0.002~0.01 s^(-1),变形温度为750~800℃,应变速率为0.049~2.718 s^(-1)和变形温度为800~1050℃、应变速率为0.1~4.482 s^(-1)的3个区域内易产生流变失稳现象;动态再结晶是触发材料流变软化及稳态流变的主要原因,Cr4合金钢的安全热加工区域的变形温度在950~1150℃之间、应变速率在0.018~0.223 s^(-1)之间。The hot deformation behavior and hot forming process characteristic of Cr4 steel were investigated via hot compression experiment under the temperature range of 750-1200 ℃ and strain rate of 0. 002-5 s^-1 on a Gleeble-1500D thermo-simulation machine, the maximum deformation degree is 55%. The processing map for Cr4 steel was constructed. The results show that the flow stress of Cr4 steel decreases rapidly with the increase of temperature, while increases gradually with the raise of strain rate. The flow instability regions appear at three different deformation parameter regions： at 750-900 ℃ and 0.002-0.01 s- 1, at 750-800 ℃ and 0.049-2. 718 s-1, as well as at 800-1050 ~C and O. 1-4. 482 s - 1. The dynamic recrystallization is the main reason for flow softening and stable flow. The hot deformation of Cr4 steel can be carried out safely in the region of 950-1150 ℃and 0. 018-0. 223 s- 1

关 键 词：特大型支承辊 Cr4合金钢 热变形行为 热加工图 动态再结晶 

分 类 号：TG317[金属学及工艺—金属压力加工]