基于等温压缩试验的20Cr2Ni4A钢Johnson-Cook本构模型及热加工图  

Johnson-Cook Constitutive Model and Hot Processing Map of 20Cr2Ni4A Steel Based on Isothermal Compression Tests

作　　者：王伟 王波[1] 闫华军[1,2,3] 马世博 张双杰 WANG Wei;WANG Bo;YAN Huajun;MA Shibo;ZHANG Shuangjie(School of Materials Science and Engineering,Hebei University of Science and Technology,Shijiazhuang 050018,China;Hebei Key Laboratory of Material Near-net Forming Technology,Shijiazhuang 050018,China;Hebei Engineering Laboratory of Aviation Lightweight Composite Materials and Processing Technology,Shijjazhuang 050018,China)

机构地区：[1]河北科技大学材料科学与工程学院,河北石家庄050018 [2]河北省材料近净成形技术重点实验室,河北石家庄050018 [3]航空轻质复合材料与加工技术河北省工程实验室,河北石家庄050018

出　　处：《热加工工艺》2020年第13期103-108,119,共7页Hot Working Technology

基　　金：河北省重点研发计划项目(19251019D);河北省高等学校科学技术研究项目(QN2019112);石家庄市科学技术研究与发展计划项目(191080071A)。

摘　　要：采用Gleeble-3500热模拟试验机在变形温度700~1000℃、应变速率0.001~1 s^-1条件下进行了20Cr2Ni4A钢的等温压缩试验。结果表明,20Cr2Ni4A钢的流动应力随变形温度的降低或应变速率的增加而增加,其在700℃变形条件下的真实应力-应变曲线的变化规律异于其它变形温度,真实应力达到峰值后,以软化机制为主,但并未出现先强化后软化的单峰型应力-应变曲线。构建了20Cr2Ni4A钢的Johnson-Cook本构模型,并对应变速率敏感系数进行了修正,修正后的本构模型的适用范围为变形温度700~1000℃、应变速率0.001~0.1 s^-1。通过对热加工图的分析,确定的20Cr2Ni4A钢合理的热加工参数范围为:变形温度925~1000℃、应变速率0.001~0.05 s^-1。本研究可为20Cr2Ni4A钢热加工工艺参数的选择提供理论依据。The isothermal compression tests of 20Cr2Ni4A steel were implemented on a Gleeble-3500 thermal simulated test machine under deformation temperature of 700-1000℃ and strain rate of 0.001-1s^-1. The results show that with the decrease of deformation temperature or the increase of strain rate, the flow stress of 20Cr2Ni4A steel increases. The change rule of true stress-strain curves at 700℃ are different from that at other deformation temperatures, when the flow stress reaches its peak, the softening mechanism is dominant, but there is no unipeak stress-strain curve strengthened first and then softened.A Johnson-Cook constitutive model of 20Cr2Ni4A steel was constructed and the strain rate sensitivity coefficient was modified. The modified constitutive model is applicable to deformation temperature of 700-1000℃ and strain rate of 0.001-0.1 s^-1. Through the analysis of hot processing map, the reasonable range of hot working parameters of 20Cr2Ni4A steel is determined as follows: deformation temperature of 925-1000℃ and strain rate of 0.001-0.05 s^-1. This study can provide a theoretical basis for the selection of hot working parameters of 20Cr2Ni4A steel.

关 键 词：20CR2NI4A钢 等温压缩 Johnson-Cook本构模型 热加工图 

分 类 号：TG301[金属学及工艺—金属压力加工] TG142[一般工业技术—材料科学与工程]