喷射成形GH738合金热变形特性及微观组织演变  

Deformation Characteristic and Microstructure Evolution of Spray Formed GH738 Alloy

作　　者：王悦 许文勇[1] 刘娜[1] 郑亮[1] 袁华[1] 李周[1] 张国庆[1] Wang Yue, Xu Wenyong, Liu Na, Zheng Liang, Yuan Hua, Li Zhou, Zhang Guoqing(Science and Technology on Advanced High Temperature Structural Materials Laboratory, Beijing Institute of Aeronautical Materials, Beijing 100095, Chin)

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《稀有金属材料与工程》2018年第3期878-883,共6页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展计划("973"计划)(2010CB631205);国家自然科学基金(51304177);国家科技支撑计划资助(2015BAE03B01)

摘　　要：在温度950~1200℃、应变速率0.13~6.5 s^(-1)及工程应变50%的条件下,利用Gleeble-3500^(TM)热模拟试验机对喷射成形GH738合金进行热压缩试验,研究了合金的热流变行为并建立了流变本构关系,结合显微组织分析及统计技术研究了合金的组织演变情况。结果表明,流变应力随温度的升高和应变速率的减小而降低。合金热变形激活能为580.81kJ·mol^(-1)。随着形变温度的升高,高位错密度处晶界弓出形核使晶界"锯齿"化并形成项链组织,在1100℃获得完全动态再结晶组织,随温度继续升高及应变速率的降低组织明显长大。The hot flow behaviors and deformation model of the spray formed superalloy GH738 were investigated using Gleeble-3500TM simulator in a temperature range of 950～1200 ℃ and a strain rate range of 0.13～6.5 s^（-1） with reduction of 50%. The evolution of microstructure was studied by microscope and image analysis system. The results show that the flow stress decreases with increasing the deformation temperature or decreasing the strain rate. The hot deformation activation energy Q is 580.81 kJ·mol^（-1）. As the temperature increases, the necklace structures are obtained along the boundaries which are protuberated by the newly recrystallized grains in the high dislocation-density serrated grain boundary zones. The structures exhibit fully dynamic recrystallization characteristic at 1100℃ while the high temperature and the low strain rate make the structure grow.

关 键 词：GH738高温合金 喷射成形 热变形本构方程 动态再结晶 

分 类 号：TG132.3[一般工业技术—材料科学与工程]