GUO Longxin, WANG Chenyang, GAO Xinliang, WANG Zhicong, GUAN Xiuge, ZHENG Bing, XU Dong
The wear-resistant steel is characterized by its high hardness, toughness, and wear-resistance. It is primarily used in construction and agricultural machinery. The wear and brittle fracture failures observed in wear-resistant steel during service are closely related to solute segregation within the steel. To elucidate the solute microsegregation behavior during the solidification process of wear-resistant steel, a microsegregation model, which takes the eutectoid transformation, inclusion precipitation, and dendrite coarsening during the solidification into consideration, was established. The model's accuracy was verified, and then the effects of C, Mn and S content, precipitation of MnS inclusions and cooling rate on the solute microsegregation behavior, zero ductility temperature (ZDT), and zero strength temperature (ZST) were analyzed. The results indicate that S and P exhibit significant microsegregation during the solidification process of wear-resistant steel, and MnS precipitation reduces the segregation degree of Mn and S. The C content has a pronounced impact on the microsegregation of solute elements, while Mn and S contents exert minimal influence on the microsegregation of solute elements. Additionally, it is observed that the effect of cooling rate on solute microsegregation varies with different solid phase fraction. The content of C, Mn and S, as well as the cooling rate, all influence the precipitation amount of MnS inclusion. Increasing C content and Mn content result in a decrease in both ZDT and ZST. With the increase of S content and cooling rate, ZDT decreases, while the variation of ZST remains minimal. The findings have important implications for the continuous casting production of wear-resistant steel.