Microstructural evolution and hardness of a heat resistant alloy during long term aging at 700 °C

作者：Jiang, Senbao; Tian, Zhongliang; Liu, Wenbo; Chen, Hao; Yang, Zhigang; Liu, Zhengdong; Zhang, Chi^*; Weng, Yuqing

来源：Journal of Alloys and Compounds, 2018, 765: 1267-1274.

DOI：10.1016/j.jallcom.2018.05.263

• Nickel alloy
• Aging
• Microstructure evolution
• Precipitation
• Hardness

The microstructural evolution of a nickel-based heat resistant alloy during long term aging (10000 h) at 700 degrees C was systematically investigated. Experimental results showed that the main precipitates after pre-aging treatments were MC, M23C6 and homogeneous gamma'. The weight fraction of gamma' increased continuously with the aging time up to 5000 h, while an obvious coarsening was observed after aging for 100 h. The grain sizes of gamma' precipitates from all aged samples exhibited unimodal distributions, and their coarsening behavior showed good agreement with the LSW model. Compared to the MC carbides, the weight fraction of the M23C6 carbides increased significantly with the increase of the aging time. This could be attributed to their precipitation from the supersaturated matrix. Due to the precipitation and coarsening of gamma', the hardness of the aged samples increased sharply during the first 100 h of aging and then decreased with the increase of the aging time (up to 10000 h).

• 出版日期2018-10-15
• 单位清华大学; 钢铁研究总院; 西安交通大学; 武汉科技大学