Productive Practice of High Quality H13 Hot Work Die Steel under the Action of PMO

To develop high-quality H13 hot work die steel continuous-casting billets and address quality issues such as segregation and shrinkage cavities， a process involving converter + LF + RH + continuous casting + rolling was adopted. By employing dual-block slide gate in the converter， full-process diffusion deoxidation during refining， and controlling the basicity of refining slag， as well as utilizing full-process protective casting and pulse magnetic oscillation （PMO） solidification homogenization technology and other auxiliary methods during continuous casting， industrial production of H13 hot work die steel was successfully achieved on a ϕ 300 mm continuous casting machine. The results showed that the process test could achieve high purity， low segregation， and uniform microstructure production of H13 hot work die steel. The steel chemical composition was accurately controlled， and corresponding indicators such as macrostructure， element segregation， and inclusions all met the technical requirements. When the PMO voltage was 185 V and the power was 42 kW， the shrinkage cavity grade of H13 steel billets could be effectively reduced from grade 2.0 to below grade 1.0， improving the carbon segregation in the core of H13 steel billets， with the average carbon segregation index in the core decreasing from 1.2 to below 1.1.