Li Bin, Shi Xiao, Guo Hanjie, Guo Jing
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials, Beijing 100083, China.
Materials (Basel). 2019 May 6;12(9):1463. doi: 10.3390/ma12091463.
In this paper, the precipitation thermodynamics and growth kinetics of TiN inclusions in GCr15 bearing steel during solidification were calculated in more detail. A more reasonable formula for calculating the segregation of the solute elements was adopted and the stability diagram of TiN precipitation considering solidification segregation was given. By solving equations, the change of the solute element content before and after TiN inclusion precipitation was calculated, and the results were substituted into the kinetic formula of the inclusion growth, which made the kinetic calculation more accurate. Results showed that the most effective way to reduce the precipitation of TiN is to increase the cooling rate and decrease the contents of Ti and N in steel. The effect of Ti content on the size of TiN inclusions is greater than that of N content.
本文更详细地计算了GCr15轴承钢凝固过程中TiN夹杂物的析出热力学和生长动力学。采用了更合理的溶质元素偏析计算公式，给出了考虑凝固偏析的TiN析出稳定性图。通过求解方程，计算了TiN夹杂物析出前后溶质元素含量的变化，并将结果代入夹杂物生长动力学公式，使动力学计算更加准确。结果表明，降低TiN析出的最有效方法是提高冷却速度和降低钢中Ti和N的含量。Ti含量对TiN夹杂物尺寸的影响大于N含量。
