球墨铸铁QT800-6的热压缩变形行为及应变补偿本构模型  

Hot compression deformation behavior and strain compensated constitutive model of QT800-6 ductile iron

作　　者：周珊 孙有平[1] 付静[1] 何江美[1] Zhou Shan;Sun Youping;Fu Jing;He Jiangmei(College of Mechanical Engineering,Guangxi University of Science and Technology,Liuzhou Guangxi 545006,Chin)

机构地区：[1]广西科技大学机械工程学院

出　　处：《金属热处理》2018年第7期49-53,共5页Heat Treatment of Metals

基　　金：广西重点研发计划(桂科AC16380032);柳州市科学研究与技术开发计划(2016C050202,2017BD20301);广西科技大学研究生教育创新计划(GKYC201604)

摘　　要：在RDL05型电子蠕变疲劳试验机上对球墨铸铁QT800-6在变形温度600-750℃、应变速率0.0001-0.01 s-（-1）条件下进行压缩试验,研究QT800-6流变应力变化规律。结果表明：随着温度的升高或应变速率的降低,流变应力逐渐减小。当温度为750℃、应变速率为0.0001 s-（-1）时,峰值应力达到最小值。获得了本构方程中材料常数和激活能随应变的变化规律,并建立了应变补偿的Arrhenius模型,模型预测值和试验值吻合较好,最大平均误差仅为4.38%,能够准确描述QT800-6的热压缩流变应力行为。Hot compressive test of QT800-6 ductile iron was carried out at temperatures from 600℃to 750℃and strain rates from 0.0001 s-（-1）to0.01 s-（-1）on a RDL05 electronic creep fatigue testing machine.The regularity of flow stress for the QT800-6 was studied.The results show that the stress level decreases with increasing deformation temperature and decreasing strain rate.The peak stress reaches the minimum at 750℃and0.0001 s-（-1）.The variation law of the material constant and the activation energy with strain in the constitutive equation is obtained.The Arrhenius constitutive relation model by using strain compensation is established.The flow stress of ductile iron predicted by model well agrees with experimental results,and the average relative error is only 4.38%,it can accurate description hot compression flow stress of QT800-6.

关 键 词：QT800-6球墨铸铁 应变补偿 热压缩 流变应力 

分 类 号：TG255[金属学及工艺—铸造]