Liu Hui, Hu Delin, Fu Jianxun
Center for Advanced Solidification Technology (CAST), School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China.
Materials (Basel). 2019 Jun 24;12(12):2028. doi: 10.3390/ma12122028.
Controlling the formation of MnS inclusions during solidification influences the mechanical properties and machinability of the resulfurized steel. A coupled segregation-nucleation-growth model was developed by the finite-difference method involving solute redistribution, heterogeneous nucleation and growth kinetics. Laboratory solidification experiments were performed under various cooling rates in resulphurised 49MnVS steel. In this work, the influence of cooling rate on solute redistribution and growth size of MnS inclusions were simulated using the current coupled model, and the calculated results can provide a valuable reference for MnS formation. Increasing of the cooling rate led to early precipitation and refinement of formed MnS inclusions. Based on the simulation results and experimental data, mathematical relationships between the growing size of MnS with the cooling rate in the low ductility temperature region and in the whole solidification were obtained.
控制凝固过程中MnS夹杂物的形成会影响再硫化钢的力学性能和可加工性。通过有限差分法建立了一个耦合偏析-形核-生长模型，该模型涉及溶质再分配、异质形核和生长动力学。在不同冷却速率下对49MnVS再硫化钢进行了实验室凝固实验。在这项工作中，利用当前的耦合模型模拟了冷却速率对MnS夹杂物溶质再分配和生长尺寸的影响，计算结果可为MnS的形成提供有价值的参考。冷却速率的增加导致已形成的MnS夹杂物提前析出并细化。基于模拟结果和实验数据，得到了低延性温度区域和整个凝固过程中MnS生长尺寸与冷却速率之间的数学关系。
