Comparative research on the elevated-temperature wear resistance of a cast hot-working die steel

The wear tests under the atmospheric conditions at 400 °C were performed for the cast die steel, commercial H13 and H21 steels. The wear behavior of the cast die steel as a function of load was studied compared with those of H13 and H21 steels. The wear mechanism and the alloying design of the cast die steel with a high wear resistance were also discussed. The XRD patterns identified that the oxidation wear was a predominated wear mechanism for these steels under the atmospheric conditions at 400 °C. With increasing load, the transition of mild oxidation wear to severe wear occurred in H13 and H21 steels, but did not appear in the cast steel. The cast steel presented a substantially lower wear loss than H13 and H21 steels. The transition was obviously delayed in the cast steel. The high wear resistance of the cast die steel was attributed to the tempered troostite with a dispersed, fine VC that inhibited the plastic deformation and crack initiation in the matrix underneath the oxides, thus postponing the variation of the delamination patterns.