摘要
利用Gleeble-3500D型热模拟实验机进行等温压缩实验,系统研究一种新型热挤压态Ni-Co-Cr基粉末高温合金在变形温度为1020~1110℃、应变速率为10-3~1 s-1条件下的热压缩变形行为,对获得的流变应力曲线进行摩擦修正,利用摩擦修正后的数据分别建立合金的热压缩本构关系方程和考虑应变补偿的流变应力模型;同时,构建热加工图,并结合显微组织分析,优化合金的热变形工艺参数。结果表明:合金在热压缩过程中发生了明显的动态再结晶现象,流变应力随应变速率的降低或变形温度的升高而降低。利用所建立的考虑应变补偿的合金流变应力模型进行流变应力的预测,其预测值与实验摩擦修正值吻合良好。根据构建的热加工图并结合微观组织分析,提出了合金较合理的热加工参数:变形温度约为1076~1103℃、应变速率约为10-3~10-2.77 s-1。
Isothermal compression tests were carried out on a Gleeble-3500D thermal simulation machine.The hot compression deformation behavior of a new hot-extruded Ni-Co-Cr-based powder metallurgy(P/M)superalloy at the temperatures from 1020℃to 1110℃with the strain rates from 10-3 s-1 to 1 s-1 was systematically investigated.The flow stress curves were corrected by friction.Using the friction-corrected data,the constitutive equation for hot compression of the alloy and the flow stress model considering the strain compensation were established,respectively.At the same time,the hot processing map was built,and the hot deformation parameters of the alloy were optimized by combining with the analysis of the microstructure.The results show that apparently dynamic recrystallization occurs in the process of hot compression of the alloy,and the flow stress decreases with the decrease of strain rate or the increase of deformation temperature.The predicted values obtained from the developed flow stress model considering the strain compensation agree well with the experimentally friction-corrected data.According to the hot processing map and microstructural analysis,the reasonable hot working parameters of the alloy were suggested to be at the deformation temperatures of about 1076-1103℃and the strain rates of about 10-3-10-2.77 s-1.
作者
李慧中
杨雷
王岩
谭钢
黄钲钦
刘敏学
LI Hui-zhong;YANG Lei;WANG Yan;TAN Gang;HUANG Zheng-qin;LIU Min-xue(School of Materials Science and Engineering,Central South University,Changsha 410083,China;School of Aeronautics and Astronautics,Central South University,Changsha 410083,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2020年第9期115-123,共9页
Journal of Materials Engineering
基金
国家重点研发计划资助项目(2016YFB0700300)
国家自然科学基金资助项目(51774335)。
关键词
镍基粉末高温合金
热压缩变形
本构方程
应变补偿
热加工图
nickel-based P/M superalloy
hot compression deformation
constitutive equation
strain com-pensation
hot processing map
作者简介
通讯作者: 王岩(1973-),女,教授,博士,从事航空航天材料的制备工艺优化、微观结构分析及性能评价等研究工作,联系地址:湖南省长沙市中南大学航空航天学院(410083),E-mail:wangyan@csu.edu.cn。
