Analysis of Nb segregation in continuous casting TP347H billet
CHEN Qi-wei1, BAO Han-sheng1, YANG Gang1, WU Ming-hua2, CAI Long3, YANG Li-xia4
1. Research Institute of Special Steels, Center Iron and Steel Research Institute, Beijing 100081, China; 2. Yongxing Spexial Materials Technology Co., Ltd., Huzhou 313099, Zhejiang, China; 3. Zhejiang Jiuli Hi-Tech Metals Co., Ltd., Huzhou 313028, Zhejiang, China; 4. NCS Testing Technology Co., Ltd., Beijing 100081, China
Abstract:Segregation of Nb is found in the TP347H billet produced by continuous casting process, inner wall cracking in cross rolling perforation is generated in the pipe after hot continuous rolling when the Nb segregation is serious, leading to the reduction of yield and low comprehensive performance of steel tube. In view of segregation phenomenon, the precipitation behavior of niobium containing precipitates was studied by means of thermodynamic calculation and experiment, the main factors affecting Nb segregation in continuous casting billet and the characteristics of primary MX phase (niobium carbonitride) precipitations were analyzed. The results show that composition optimization of TP347H steel produced by continuous casting process should focus on the content of C and Nb elements. And the segregation phenomenon of continuous casting TP347H billet exists in the central area of the billet, which leads to the difference in morphology and size of the primary MX phase precipitations between edge and central area of billet.
陈其为, 包汉生, 杨钢, 吴明华, 蔡珑, 杨丽霞. 连铸TP347H钢坯中Nb的偏析现象分析[J]. 中国冶金, 2022, 32(6): 61-70.
CHEN Qi-wei, BAO Han-sheng, YANG Gang, WU Ming-hua, CAI Long, YANG Li-xia. Analysis of Nb segregation in continuous casting TP347H billet[J]. China Metallurgy, 2022, 32(6): 61-70.
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