Precipitation characteristics of the carbides for Mn13 high manganese steel slab during cooling
LIN Hong-liang1, SHANG Xiu-ling2, SHI Bin-qing3
1. Guangdong High end Stainless Steel Research Institute Co., Ltd., Yangjiang 529533, Guangdong, China; 2. GD Midea Air-Conditioning Equipment Co., Ltd., Foshan 528311, Guangdong, China; 3. School of Materials Science and Hydrogen Energy, Foshan University, Foshan 528300, Guangdong, China
Abstract:After Mn13 steel was produced by continuous casting process in some enterprise, a large number of layered cracks along the central plane appeared after hot rolling, and the cracking ratio was much higher than that of die cast billet. Initial testing results have confirmed that such issue was related to coarse carbide precipitation in the center of the billets. Therefore, it is necessary to focus on the carbide precipitation characteristics of Mn13 steel continuous casting billet during solidification and cooling. In this work, the precipitation behavior of carbides was investigated through Thermo-calc thermodynamic calculation and laboratory heat-treatment simulation. The calculation results show that under the condition of thermodynamic equilibrium, carbides begin to precipitate at 847 ℃, and all carbides precipitate at 557 ℃. The results of microstructure observation show that no visible carbides precipitate from the matrix above 650 ℃. When the temperature is cooled to 550 ℃, the carbide begins to precipitate obviously. The temperature range of 400-550 ℃ is a sensitive temperature range for carbide precipitation, therefore the continuous casting billet should be subjected to rapid cooling to avoid carbide precipitation in this temperature range. In addition, the process practice shows that the adoption of reasonable continuous casting processes (such as proper molten steel superheat, electromagnetic stirring and dynamic soft reduction processes) can also help to improve the central segregation of Mn13 steel billets and reduce the tendency of carbide precipitation in the core during the solidification process of billets.
林鸿亮, 尚秀玲, 施斌卿. Mn13高锰钢连铸坯冷却过程中碳化物的析出特征[J]. 连铸, 2023, 42(1): 66-73.
LIN Hong-liang, SHANG Xiu-ling, SHI Bin-qing. Precipitation characteristics of the carbides for Mn13 high manganese steel slab during cooling. CONTINUOUS CASTING, 2023, 42(1): 66-73.
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