Heat Treatment of Metals ›› 2024, Vol. 49 ›› Issue (8): 178-182.DOI: 10.13251/j.issn.0254-6051.2024.08.031

• PROCESS RESEARCH • Previous Articles     Next Articles

Second phase precipitation of high nitrogen austenitic stainless steel for retaining ring

Zhang Ronghua1, Song Wenzhi1, Zhao Fuqiang2, Zhang Shizhe2, Liu Qian1   

  1. 1. Key Laboratory of the Ministry of Education for Modern Metallurgy Technology, College of Metallurgy and Energy, North China University of Science and Technology, Tangshan Hebei 063210, China;
    2. MCC Qinhuangdao Engineering Design and Research Institute Co., Ltd., Qinhuangdao Hebei 066000, China
  • Received:2024-02-16 Revised:2024-05-31 Online:2024-08-25 Published:2024-09-27

Abstract: Second phase precipitation process of high nitrogen austenitic stainless steel was studied by XRD, OM, SEM and TEM. The morphology and the type of precipitated phases were analyzed and determined. The experimental results show that the microstructure of the solution treated specimen is composed of single-phase austenite grains and partial twins. After aging at 800-1040 ℃ for 2 h, Cr2N precipitates in the steel, and the number of Cr2N increases first and then decreases, which reaches the peak at 860 ℃. The precipitated phases of the tested steel are mainly carbide, nitride and intermetallic compound σ phase. Aged at 800 ℃, the intermetallic compound σ phase is precipitated, and M23C6 carbide is precipitated at 860 ℃. Only Cr2N is precipitated after aging at 920 ℃, and MX phase is precipitated at 1040 ℃.

Key words: high nitrogen austenitic stainless steel, precipitated phase, aging, microstructure

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