σ-Phase Precipitation Mechanism of 15Cr–15Ni Titanium-Modified Austenitic Stainless Steel During Long-Term Thermal Exposure
来源期刊：Acta Metallurgica Sinica2018年第3期
论文作者：Zhi-Nan Wang Tian Liang Wei-Wei Xing Ai-Bing Du Ming Gao Ying-Che Ma Kui Liu
文章页码：281 - 289
摘 要：The σ-Phase precipitation in 20% cold-worked 15Cr–15Ni titanium-modified austenitic stainless steel was studied during long-term aging treatment. During the isothermal aging stage, the amount of σ-Phase was significantly increased at beginning and gradually became constant. The aging time only slightly affected the size and morphology of the σ-Phase. Conversely, during the isochronal aging stage, the amount of σ-Phase grew rapidly with the increase in the aging temperature. The σ-Phase with a large amount of stacking faults was prone to nucleate around the（Ti, Mo）C particles or at the grain boundaries. The（Ti, Mo）C particles can act as effective nucleation sites, where the σ-Phase directly precipitates from the austenitic matrix. From this work, the growth of σ-Phase is found to be influenced by the aging temperature, and a new mechanism of σ-Phase precipitation from austenite has been proposed.
Zhi-Nan Wang1，Tian Liang1，Wei-Wei Xing1，Ai-Bing Du2，Ming Gao1，Ying-Che Ma1，Kui Liu1
1. Key Laboratory of Nuclear Materials and Safety Assessment,Institute of Metal Research, Chinese Academy of Sciences2. China Institute of Atomic Energy
摘 要：The σ-Phase precipitation in 20% cold-worked 15Cr–15Ni titanium-modified austenitic stainless steel was studied during long-term aging treatment. During the isothermal aging stage, the amount of σ-Phase was significantly increased at beginning and gradually became constant. The aging time only slightly affected the size and morphology of the σ-Phase. Conversely, during the isochronal aging stage, the amount of σ-Phase grew rapidly with the increase in the aging temperature. The σ-Phase with a large amount of stacking faults was prone to nucleate around the（Ti, Mo）C particles or at the grain boundaries. The（Ti, Mo）C particles can act as effective nucleation sites, where the σ-Phase directly precipitates from the austenitic matrix. From this work, the growth of σ-Phase is found to be influenced by the aging temperature, and a new mechanism of σ-Phase precipitation from austenite has been proposed.
关键词：
