热挤压态FGH96合金热变形行为及变形机制研究  

Hot Deformation Behavior and Deformation Mechanism of Hot Extruded FGH96 Superalloy

作　　者：刘晓燕[1] 张习祎 陈秀全 孙靖石 张博言 杨艳慧[2] Liu Xiaoyan;Zhang Xiyi;Chen Xiuquan;Sun Jingshi;Zhang Boyan;Yang Yanhui(School of Metallurgy Engineering,Xi'an University of Architecture and Technology,Xi’an 710055,China;School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]西北工业大学材料学院,陕西西安710072

出　　处：《稀有金属》2024年第8期1108-1119,共12页Chinese Journal of Rare Metals

基　　金：装备预研重点实验室基金项目(6142903200304);陕西省教育厅重点实验室项目(20JS075)资助。

摘　　要：采用Gleeble-3500热模拟试验机,通过热压缩实验对热挤压态FGH96合金进行研究,得到了变形温度为1020~1090℃,应变速率为0.001~1 s^(-1),变形量为60%(最大真应变为0.9)下合金的热变形行为;通过热压缩实验得到真应力-应变曲线和金相等表征微观组织,得到了不同变形条件下的应变速率敏感性指数m值、变形激活能Q值和晶粒指数p值,构建了材料的热加工图及R-W-S型变形机制图。结果表明,热挤压态FGH96合金的流变应力随变形温度的升高和应变速率的降低而降低,合金的m值随温度增高呈现先增加后降低的趋势,m值的取值范围为0.212~0.243。变形激活能呈现先减小后增大的趋势,Q值的变化范围为200~360 kJ·mol^(-1)。p值随着温度增加呈现先增加再减小的趋势,呈现与m值变化规律相同的趋势变化,p值的取值范围为1.89~2.76。当变形温度为1070℃时,m值为0.243, p值为2.76, Q达到最小值,为201.185 kJ·mol^(-1),此时该合金的成形性能较好。失稳区域较小且位置相对集中,一般位于高应变速率区域,其他位置均为安全区域,当应变为0.9时,FGH96合金失稳区位于:1038~1055℃,0.05~0.1 s^(-1),最优的热加工参数为1035~1055℃,0.001~0.005 s^(-1)。其中,变形温度为1070℃时,低应变速率下(0.001~0.005 s^(-1)),挤压态FGH96合金变形机制为晶格扩散控制的位错滑移;较高应变速率下(0.01~1 s^(-1)),为位错管扩散控制的位错管晶界滑移。FGH96 is the second generation of damage tolerance powder metallurgy superalloy in China,with a maximum service temperature of 700℃.Due to its excellent comprehensive mechanical properties,corrosion resistance and high temperature oxidation resistance,FGH96 superalloy has become the first choice for the preparation of high thrust ratio advanced aero-engine turbine disc,ring and other hot end parts in China.However,due to its high alloying degree,its thermal processing performance is poor,and its thermal deformation behavior has a great influence on its micro-structure evolution and properties.Therefore,researching the hot deformation behavior of this superalloy and its hot working window has great significance,and for FGH96 superalloy research focused on based on the hot compression experimental data,build the constitutive equation,to set up the hot processing maps,and for FGH96 superalloy energy dissipation,dislocation movement and deformation mechanism of content less reported.Therefore,the hot deformation behavior of hot extruded FGH96 superalloy was studied by hot compression experiment,and the change law of hot deformation activation energy and strain rate sensitive index was analyzed in this paper.Based on dynamic materials model(DMM),the hot processing maps including the safety region and instability region was established.By introducing the material parameters of FGH96 superalloy into Ruano-Wadsworth-Sherby(R-W-S)mechanism diagram,the deformation mechanism diagram of FGH96 superalloy at different temperatures was constructed,and the quantitative relationship between the flow stress value and the grain size during the high temperature deformation was given.The micro-structure was observed by optical microscopy(OM)and transmission electron microscopy(TEM).The original micro-structure of FGH96 superalloy used in this paper was relatively uniform,and the average grain size was about 9μm.The hot compression experiments of hot extruded FGH96 superalloy were carried out by Gleeble-3500 thermal simulation mach

关 键 词：FGH96合金 应变速率敏感性指数m 晶粒指数p 热加工图 变形机制图 

分 类 号：TG132.3[一般工业技术—材料科学与工程]