摘要
采用光学显微镜和扫描电子显微镜研究一种可用于先进超超临界机组的新型镍基合金TG700A在时效期间的析出行为,并讨论时效对该合金硬度和冲击性能的影响,同时,采用应力松弛方法对其高温蠕变行为进行了研究。结果表明:M_(23)C_6碳化物在晶界上析出并迅速长大,充满晶界后其长大速度逐渐放缓;主要强化相γ′在时效期间发生粗化,形态由球形逐渐向立方形转变。时效后,该合金的冲击韧性显著下降;合金的硬度和蠕变激活能随着时效时间的延长呈现出先增加后降低的趋势,分析认为这与γ′粒子强化机制的转变有关。
The precipitation behavior of a newly developed Ni-base superalloy TG700 A was investigated by OM and SEM during aging at 770 ℃. And the effects of aging treatment on the room temperature hardness and impact toughness of TG700 A were discussed, meanwhile, the stress relaxation test was used to analyze the creep behavior of this alloy. The results show that M（23）C6 carbides rapidly precipitate and grow at grain boundaries until they are covered the grain boundaries. Subsequently, the growth rate of M（23）C6 carbides slow gradually. As a primary strengthening phase, γ′ precipitates become coarse during aging. And the morphology of γ′ particles transforms from the approximately spherical to rounded cubic. The room temperature impact toughness decreases obviously after aging. Also, the hardness and creep activation energy of the alloy increase first, and then continuously decrease with the increase of aging time, as a result of the transition of γ′ precipitates strengthening mechanisms.
作者
许庆爽
曹铁山
徐芳泓
方旭东
程从前
赵杰
XU Qing-shuang;CAO Tie-shan;XU Fang-hong;FANG Xu-dong;CHENG Cong-qianl;ZHAO Jie(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;Taiyuan Iron and Steel Group Co.,Ltd.,Taiyuan 030003,China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2018年第8期1559-1567,共9页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(U1610256)
国家高技术研究发展计划资助项目(2015AA034402)~~
关键词
镍基合金
析出相
力学性能
应力松弛
Ni-base superalloy
precipitate
mechanical property
stress relaxation
