Coarsening behavior of MX carbonitrides in type 347H heat-resistant austenitic steel during thermal aging
来源期刊：International Journal of Minerals Metallurgy and Materials2016年第3期
论文作者：Ying-hui Zhou Chen-xi Liu Yong-chang Liu Qian-ying Guo Hui-jun Li
文章页码：283 - 293
摘 要：In this work, the growth kinetics of MX（M = metal, X = C/N） nanoprecipitates in type 347 H austenitic steel was systematically studied. To investigate the coarsening behavior and the growth mechanism of MX carbonitrides during long-term aging, experiments were performed at 700, 800, 850, and 900°C for different periods（1, 24, 70, and 100 h）. The precipitation behavior of carbonitrides in specimens subjected to various aging conditions was explored using carbon replicas and transmission electron microscopy（TEM） observations. The corresponding sizes of MX carbonitrides were measured. The results demonstrates that MX carbonitrides precipitate in type 347 H austenitic steel as Nb（C,N）. The coarsening rate constant is time-independent; however, an increase in aging temperature results in an increase in coarsening rate of Nb（C,N）. The coarsening process was analyzed according to the calculated diffusion activation energy of Nb（C,N）. When the aging temperature was 800–900°C, the mean activation energy was 294 kJ ·mol-1, and the coarsening behavior was controlled primarily by the diffusion of Nb atoms.
Ying-hui Zhou，Chen-xi Liu，Yong-chang Liu，Qian-ying Guo，Hui-jun Li
State Key Lab of Hydraulic Engineering Simulation and Safety, School of Materials Science and Engineering, Tianjin University
摘 要：In this work, the growth kinetics of MX（M = metal, X = C/N） nanoprecipitates in type 347 H austenitic steel was systematically studied. To investigate the coarsening behavior and the growth mechanism of MX carbonitrides during long-term aging, experiments were performed at 700, 800, 850, and 900°C for different periods（1, 24, 70, and 100 h）. The precipitation behavior of carbonitrides in specimens subjected to various aging conditions was explored using carbon replicas and transmission electron microscopy（TEM） observations. The corresponding sizes of MX carbonitrides were measured. The results demonstrates that MX carbonitrides precipitate in type 347 H austenitic steel as Nb（C,N）. The coarsening rate constant is time-independent; however, an increase in aging temperature results in an increase in coarsening rate of Nb（C,N）. The coarsening process was analyzed according to the calculated diffusion activation energy of Nb（C,N）. When the aging temperature was 800–900°C, the mean activation energy was 294 kJ ·mol-1, and the coarsening behavior was controlled primarily by the diffusion of Nb atoms.
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