Abstract
The effect of Y-Ce complex modification on the thermal fatigue (TF) behavior of cast hot working die steels was investigated and the mechanism of Y-Ce action was discussed. The experimental result showed that TF behavior of the steel modified by Y-Ce complex modification under thermal cycling temperatures of 650-25°C was over 1.5 times than that of the unmodified, which is likely due to the enhancing of the resistance to oxidation. At the same time, after the Y-Ce complex modification, impact toughness was also increased by nearly 200%, which is mainly attributed to the great improvement of the morphology and distribution of inclusions and the reduction of their amount.
