Co(-30Ni)-7Al-7Mo新型钴基高温合金的热变形行为  

Hot deformation behavior of Co(-30Ni)-7Al-7Mo novel cobalt-based superalloy

作　　者：何宁 梁泽腾 任威[1] 王淼 孙鹏伟 李誉之 HE Ning;LIANG Ze-teng;REN Wei;WANG Miao;SUN Peng-wei;LI Yu-zhi(College of Mechanical and Electrical Engineering,Shaanxi University of Science&Technology,Xi′an 710021,China)

机构地区：[1]陕西科技大学机电工程学院,陕西西安710021

出　　处：《陕西科技大学学报》2024年第2期146-155,共10页Journal of Shaanxi University of Science & Technology

基　　金：中国博士后科学基金项目(2021M693856)。

摘　　要：利用Gleeble-3500热模拟试验机对真空电弧熔炼+固溶处理(1300℃)的Co-7Al-7Mo和Co-30Ni-7Al-7Mo进行热模拟压缩,研究变形温度在700℃~900℃、应变速率为0.001~0.1 s^(-1)时的热变形行为.分析真应力应变曲线,结果表明:Co-7Al-7Mo和Co-30Ni-7Al-7Mo在900℃,应变速率为0.001 s^(-1)时变形过程包括加工硬化+动态回复,分为4个阶段,即Ⅰ(加工硬化阶段)、Ⅱ(过渡阶段)、Ⅲ(软化阶段)和Ⅳ(稳定阶段).变形温度较低或应变速率较高时由于合金中γ′强化相阻碍再结晶,没有明显的回复软化阶段,硬化效应持续至发生断裂.在γ′相的固溶温度以下,加入30%原子百分比Ni元素后,由于γ′相体积分数的增加和固溶温度的提高,对比相同加载条件下的流变应力值明显增大.建立两种合金的Arrhenius本构方程,同时结合热加工图分析得出两种合金在变形温度为700℃~900℃,应变速率为0.001~0.01 s^(-1)时良好的加工区.Using a Gleeble-3500 thermal simulation testing machine,the thermal deformation behavior of Co-7Al-7Mo and Co-30Ni-7Al-7Mo subjected to vacuum arc melting and solid solution treatment(1300℃)was studied at deformation temperatures ranging from 700℃to 900℃and strain rates ranging from 0.001 to 0.1 s^(-1).Analyzing the true stress-strain curves,the results show that the deformation process of Co-7Al-7Mo and Co-30Ni-7Al-7Mo at 900℃with a strain rate of 0.001s^(-1)includes work hardening+dynamic recovery,which is divided into 4 stages,namelyⅠ(work hardening stage),Ⅱ(transition stage),Ⅲ(softening stage)andⅣ(stable stage).When the deformation temperature is low or the strain rate is high,because theγ′strengthening phase in the alloy hinders recrystallization,there is no obvious recovery softening stage,and the hardening effect continues until fracture occurs.When the solution temperature ofγ′phase is below,the flow stress under the same loading condition increases obviously with the increase of the volume fraction ofγ′phase and solution temperature with the addition of 30%atomic percentage Ni.The Arrhenius constitutive equations of the two alloys were established,and combined with the analysis of the thermal processing diagram,the good processing zones of the two alloys were obtained when the deformation temperature was 700℃to 900℃and the strain rate was 0.001 to 0.01 s^(-1).

关 键 词：钴基高温合金 热变形行为 本构模型 热加工图 

分 类 号：TG132.3[一般工业技术—材料科学与工程]