镍基合金740H的组织结构与析出相分析  

Microstructure and Precipitates of Alloy 740H

作　　者：郭岩[1] 周荣灿[1] 张红军[1] 张周博 侯淑芳[1] 王博涵[1] 

机构地区：[1]西安热工研究院有限公司,陕西省西安市710032

出　　处：《中国电机工程学报》2015年第17期4439-4444,共6页Proceedings of the CSEE

基　　金：国家高技术研究发展计划(863计划)(2012AA050501);国家能源应用技术研究及工程示范项目(NY20110102);2010年度中国电机工程学会电力青年科技创新项目(003)~~

摘　　要：分析了镍基合金740 H在不同状态下的组织结构和析出相的种类及其对室温硬度和冲击韧性的影响。供货态镍基合金740 H晶内含TiN和（Nb,Ti）C颗粒，晶界分布一些M23C6颗粒；经800℃×16 h标准热处理后，晶内析出细小γ＇颗粒，晶界析出少量碳化物；硬度明显提高，冲击韧性显著降低，分别为304 HB和37.5 J/cm2。时效后，γ＇相尺寸呈逐步增大趋势且与基体保持共格关系，晶界碳化物数量明显增多。750℃下时效300~3000 h 过程中硬度和韧性的变化范围分别为323~331 HB和25~35 J/cm2，时效态740 H韧性的稳定性高于740合金。Microstructure and precipitates and their effects on the room-temperature hardness and impact toughness of alloy 740H with different conditions were investigated. The as-received alloy contains （Nb,Ti） C and TiN particles inside grains and some discontinuous M23C6 carbide particles along grain boundaries. After an aging treatment at 800℃ for 16h and cooled in air （standard heat-treated condition）, a large number of extreme fineγ＇ particles precipitated within grains and small carbide particles are located along grain boundaries. The hardness is increased to 304HB and impact toughness is remarkably decreased to 37.5J/cm2 after standard heat treatment, respectively. At 750℃, aging results in an increase of M23C6 particles at grain boundaries and coarsening ofγ＇ phase. In the period of 300~3000h aging, the coherency betweenγ＇ and matrix is maintained and the hardness and toughness are 323~331HB and 25~35J/cm2, respectively. The stability of toughness of the aged alloy 740H is greater than those of the aged alloy 740.

关 键 词：镍基高温合金 740 740H 时效 组织结构 析出相 

分 类 号：TG113[金属学及工艺—物理冶金]