9Cr-2W耐热合金高温变形机制研究  

Hot Deformation Mechanism of 9Cr-2W Heat-Resistant Alloy

作　　者：孙述利[1] 何文武[1] 张敏刚[1] 柴跃生[1] 

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《稀有金属》2013年第4期557-563,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金(51275332);山西省科技攻关项目(20090322007);太原科技大学博士启动基金项目(20122012;20122013);山西省研究生优秀创新项目(20081083;20081084)资助

摘　　要：对9Cr-2W耐热合金进行了热变形温度900～1300℃和应变速率0.005～5.000 s-1条件下热压缩模拟实验,分析该合金热变形应力应变曲线、热变形组织演变,并测试1150和1300℃下的热变形织构。结果表明,9Cr-2W耐热合金热变形软化方式主要与温度有关,在应变速率0.500 s-1时,900～1050℃出现明显加工硬化,为动态回复型;1100～1200℃动态再结晶新晶粒沿原晶界分布,为不连续动态再结晶型;1250～1300℃沿原晶界出现锯齿形,为几何动态再结晶型。同时,应变速率对热变形软化方式也有一定的影响,随着应变速率的提高,发生不连续动态再结晶温度范围变宽,细化晶粒效果明显。结合9Cr-2W耐热合金变形织构特征,1150℃热变形组织以动态回复为主,织构相对集中,晶粒择优取向强一些;而1300℃热变形组织基本为等轴晶粒,发生了完全动态再结晶,相对应织构漫散,择优取向相对弱一些。Abstract： The hot compression simulation experiment of 9Cr-2W heat-resistant alloy was carried out with hot deformation temperature of 900 - 1300 ℃ and strain rates of 0.005 - 5. 000 s -1. Hot deformation characteristics of stress-strain curves, hot deformation micro- structure evolution, and hot deformation textures at 1150 and 1300 ℃ of the alloy were measured and analyzed. The results indicated that the softening ways of hot deformation microstrueture for 9Cr-2W heat-resistant alloy was mainly related to temperature. When the strain rate was 0.500 s- 1, the stress strain curves exhibited strain hardening behavior and the microstructure evolution mechanism was dynamic recovery type from 900 to 1050 ℃ ; the curves exhibited flow softening behavior. Recrystallized, equiaxed and uniform grains of dynamic reerystallization distributed along prior grain boundaries and the mechanism was discontinuous dynamic reerystallization from 1100 to 1200℃ ; prior grain boundaries became serrated and the mechanism was geometric dynamic reerystallization from 1250 to 1300 ℃. At the same time, strain rate had certain effect on hot deformation softening ways, the temperature range appearing discontinuous dynamic recrystallization became larger with the increase of strain rate, grain sizes were dramatically refined. The hot deformation tex- tures characteristics of 9Cr-2W heat-resistant alloy implied that hot deformation mierostructure was mainly dynamic recovery type at 1150℃, the corresponding texture was centralized and it had stronger preferred orientation; but hot deformation micrestructure was ba- sically equiaxed grains at 1300 ℃, the corresponding texture was diffused and it had weaker preferred orientation.

关 键 词：9Cr-2W耐热合金 动态回复 几何动态再结晶 变形织构 

分 类 号：TG146.2[一般工业技术—材料科学与工程]