Precipitation and Evolutionary Behavior of Eutectic Carbides in Electroslag Remelted 7Cr13N Steel

The precipitation and evolutionary behavior of eutectic carbides in 7Cr13N steel were investigated and compared with 8Cr13MoV steel. The results showed that the eutectic carbide precipitation at the center and edge of 7Cr13N ingot was reduced by 26.8% and 67.0% compared with 8Cr13MoV ingot. The decrease in carbon content and the increase in solid mass fraction at the start of carbide precipitation are the main reasons for the decrease in eutectic carbide precipitation in 7Cr13N steel. Eutectic carbide will be broken during the cogging process to increase its volume fraction. Then, the eutectic carbides will be dissolved during the diffusion annealing process, and the undissolved eutectic carbides will be further broken and dispersed during the hot rolling process. The eutectic carbide will not change basically after the end of hot rolling. The size of the eutectic carbide that remains in the final tool is between 3-5 mu m.