Industrial Trials on Preparation of Cerium-Treated H13 Steel by Electroslag Remelting with Cerium-Oxide Containing Slag

To realize an industrial production of a cerium-treated electroslag remelted H13 steel, electroslag remelting (ESR) of H13 steel using a CaF2-CeO2-CaO-Al2O3 system slag combined with a Si-Ca reductant addition is studied. The influence of the Al2O3 content in the slag on the cerium treatment effect of cerium-oxide-containing slag is investigated to determine the appropriate slag. A 52.2 wt% CaF2-26.7 wt% CeO2-17.8 wt% CaO-3.3 wt% Al2O3 slag (RE-Slag) is employed for the industrial ESR production of H13 steel. An H13 steel remelted by a 70 wt% CaF2-30 wt% Al2O3 slag (CA-Slag) is used for comparison. Al2O3 can suppress the reduction of cerium oxide by changing the activities of slag components. ESR with RE-Slag achieves a cerium treatment of H13 steel. However, an uneven distribution of Ce is obtained due to the limitation of the reductant addition method. The H13 steel remelted with RE-Slag (RE-Slag-H13) has higher cleanliness, finer dendritic structures, and finer primary carbides than those of the steel remelted with CA-Slag (CA-Slag-H13). Compared to the forged CA-Slag-H13 steel, the banded segregation of the RE-Slag-H13 steel is suppressed, and the impact toughness is increased by 30%.