Study Of Erosion Resistance Of Cast Hot-working Die Steels In Molten Aluminum

The cast die steels and H13 steels samples with different compositions and surface conditions were immerged into the molten aluminum liquid at different temperatures and kept for different hours. We also investigated the microstmctures of the interface between the steel matrix and aluminum with EDS,SEM .Through above methods to analysis the effects of different technical factors to the erosion resistance ability of die steels, hereby designed new cast die steel of high erosion resistance ability and compared that with H13 steel.The results showed that during immersing die steels in molten aluminum liquid three different layers were formed. The surface layer was consisted of Al-Si alloy which had similar compositions with the Al alloy used in the experiment; The transition layer was consist of different Fe-Al-Si intermetallic phases; The matrix was the steel used in the experiment. From the experiment results showed that the melting-loss of the samples increased with the immersion time and immersion temperature. The die steels of higher chromium and lower vanadium contents showed better erosion resistance ability under 750℃.The element Si in aluminum alloy reduced the interaction between die steels and aluminum alloy melt and reduced the soldering tendency of aluminum die casting which lead less melting-loss. We also studied the surface conditions of the die steels, from the results it showed that the samples with oxidation surface had the most erosion resistance ability and the samples with crude surface got the worst erosion resistance ability. The new cast die steels designed from the experiment analysis had better erosion resistance ability than H13 steel widely used in industrial.