GH4698合金热加工图及微观组织演化  

Hot processing maps and microstructure evolution of GH4698 alloy

作　　者：李中豪 黄亮[1] 班宜杰 温东旭 李建军[1,2] 蒋乔 杨晓利 张健 张志成 LI Zhong-hao;HUANG Liang;BAN Yi-jie;WEN Dong-xu;LI Jian-jun;JIANG Qiao;YANG Xiao-li;ZHANG Jian;ZHANG Zhi-cheng(State Key Laboratory of Materials Processing and Die&Mould Technology,School of Material Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Hubei Huangshi Mold Industrial Technology Research Institute,Huangshi 435001,China;Daye Special Steel Co.,Ltd.,Huangshi 435001,China;Hubei Key Laboratory of High Quality Special Steel,Huangshi 435001,China)

机构地区：[1]华中科技大学材料科学与工程学院材料成形与模具技术全国重点实验室,湖北武汉430074 [2]湖北黄石模具产业技术研究院,湖北黄石435001 [3]大冶特殊钢有限公司,湖北黄石435001 [4]高品质特殊钢湖北省重点实验室,湖北黄石435001

出　　处：《塑性工程学报》2024年第1期71-82,共12页Journal of Plasticity Engineering

基　　金：国家重点研发计划(2022YFB3706901,2022YFB3706903);湖北省重点研发计划(2022BAA024)。

摘　　要：针对GH4698合金进行了热变形行为研究,分析了其在变形温度为960~1160℃、应变速率为0.001~10 s^(-1)下的微观组织演化规律和热加工性能。绘制了GH4698合金的动态再结晶(DRX)图来分析微观组织演化机制。此外,构建了DRX晶粒的平均晶粒尺寸图,分析了DRX对微观组织的影响,构建了3D失稳图和3D功率耗散图来评估热加工性能,获得了最优的热加工区间。结合DRX程度以及DRX晶粒平均尺寸进一步优化了热加工区间,优化后的变形温度为1017~1065℃、应变速率0.001~0.005 s^(-1),以及热变形温度为1087~1160℃、应变速率0.017~0.115 s^(-1)。同时,利用电子背散射衍射技术表征了材料的微观结构。结果表明:材料的组织对应变速率较为敏感,DRX体积分数与应变速率成反比。不连续动态再结晶(DDRX)是GH4698合金的主要变形机制。具体为:低应变速率下主要是DDRX,中应变速率下主要是连续动态再结晶(CDRX),高应变速率下是CDRX+DDRX;低温时DRX的机制为CDRX+DDRX,高温时DRX的机制主要为DDRX。The hot deformation behaviors of GH4698 superalloy were studied.The microstructure evolution laws and hot working performance were analyzed under the conditions with deformation temperature of 960~1160℃,and strain rate of 0.001~10 s^(-1).The dynamic recrystallization(DRX)diagrams of GH4698 alloy were constructed to analyze the microstructure evolution mechanism.In addition,the average grain size diagrams of DRX grains were constructed to analyze the infulence of DRX on microstructure,the 3D instability diagram and 3D power dissipation diagram were constructed to evaluate the hot working performance,and the optimum hot working interval was obtained.According to the DRX degree and the average grain size of DRX,the hot working interval was further optimized and the optimized deformation temperature is 1017-1065℃,the strain rate is 0.001-0.005 s^(-1),and the deformation temperature is 1087-1160℃,the strain rate is 0.017-0.115 s^(-1).At the same time,the microstructure of the material was characterized using electron backscattered diffraction(EBSD)technology.The results show that the microstructure of the material is sensitive to strain rate,and the volume fraction of DRX is inversely proportional to strain rate.Continuous dynamic recrystallization(DDRX)is the main deformation mechanism of GH4698 alloy.It is mainly show that DDRX predominating at low strain rates,CDRX predominating at medium strain rates,and CDRX+DDRX predominating at high strain rates;the mechanism of DRX is CDRX+DDRX at low temperatures,while the main DRX mechanism is DDRX at high temperatures.

关 键 词：GH4698 热加工图 微观组织 动态再结晶 

分 类 号：TG132.3[一般工业技术—材料科学与工程]