34CrNiMo6钢的高温流变行为及热加工图  

High temperature rheological behavior and thermal processing diagram for 34CrNiMo6 steel

作　　者：苟春梅[1] 董静[1] 崔丹丹 Gou Chunmei;Dong Jing;Cui Dandan(Institute of Automotive Engineering,Xinjiang Vocational and Technical College of Communications,Urumqi 831401,China)

机构地区：[1]新疆交通职业技术学院汽车工程学院,新疆乌鲁木齐831401

出　　处：《锻压技术》2023年第2期233-240,共8页Forging & Stamping Technology

基　　金：全国交通运输职业教育科研项目(2019B57)。

摘　　要：研究了34CrNiMo6钢的高温流变特性,并获得了其最佳热加工工艺窗口。首先,使用Gleeble-3500热模拟实验机对34CrNiMo6钢在变形温度为1173~1473 K、应变速率为0.001~1 s^(-1)条件下进行等温热压缩实验,得到了不同应变速率和变形温度下的真实应力-真实应变曲线,并用Arrhenius模型对材料本构关系进行多元非线性回归,结果表明其回归精度较高。其次,使用流变数据构建了34CrNiMo6钢的热加工图并进行分析,考虑到所有应变情况,34CrNiMo6钢热加工工艺窗口应避开变形温度低于1300 K、应变速率高于0.05 s^(-1)和变形温度高于1400 K、应变速率高于0.14 s^(-1)的区域。最后,金相分析表明:34CrNiMo6钢在应变速率敏感系数、能量耗散率及失稳判据较小的区域具有晶粒不均匀、晶界不规则的特点,这是由于此时动态再结晶不完全;而在应变速率敏感系数、能量耗散率及失稳判据较大的区域发生完全动态回复和动态再结晶,组织比较均匀。The high temperature rheological properties of 34CrNiMo6 steel was studied and the best thermal processing window was obtained.Firstly,the isothermal thermal compression test of 34CrNiMo6 steel was carried out by Gleeble-3500 thermal simulated test machine under the deformation temperature of 1173-1473 K and the strain rate of 0.001-1 s^(-1),and the true stress-true strain curves under different strain rates and deformation temperatures were obtained.Then,the Arrhenius model was used to conduct multiple nonlinear regression on the constitutive relationship of the material,and the results show that the regression accuracy is high.Secondly,the thermal processing diagram of 34CrNiMo6 steel was constructed and analyzed by using the rheological data,and considering all strain conditions,the thermal processing window of 34CrNiMo6 steel should avoid the regions where the deformation temperature is lower than 1300 K and the strain rate is higher than 0.05 s^(-1),and the deformation temperature is higher than 1400 K and the strain rate is higher than 0.14 s^(-1).Finally,the metallographic analysis shows that 34CrNiMo6 steel has the characteristics of inhomogeneous grains and irregular grain boundaries in the region where the strain rate sensitivity coefficient,energy dissipation rate and instability criterion are small,which is due to incomplete dynamic recrystallization.However,complete dynamic recovery and dynamic recrystallization occur in the region where the strain rate sensitivity coefficient,energy dissipation rate and instability criterion are relatively large,and the microstructure is relatively uniform.

关 键 词：34CrNiMo6钢 高温流变行为 Arrhenius模型 热加工图 动态再结晶 

分 类 号：TG142[一般工业技术—材料科学与工程]