| The properties of high-sulfur alloy steel (HS) were determined by the size, shape and distribution of sulfides in the steel. HS was cast by using different thickness of iron mold and sand mold, respectively. The influence of solidification rate of HS on the size, the shape and the distribution of sulfides were investigated by means of SEM. Some specimens were heat treated to analyze the sulfide and structure state of HS in different heat treated histories and the mechanical properties and wear resistance were tested.The size, shape and distribution of sulfides in the HS were quantitatively analyzed and the results showed that the sulfides in rapid solidification HS appeared as tiny spheroid dispersed in the matrix, but in slow solidification ones a large irregular ellipsiods were found in grain boundary. The matrix structure changed from martensite to pealile structure.Heated at 850℃, the matrix of HS cannot be fully austenited and were still pearlite structure after quenching, showing low hardness. Heated at 950℃and 1000℃, the austenite grain were significantly coarsen and quenched structure also showed a poor hardness because of coarse martensite. Quenched at 900℃, the average size of the sulfides in HS was the smallest and so was the volume percentage. When the heat treatment temperature was above 900℃, sulfides gathered with size increased.The wear amount of the HS is the least for the specimen quenched in 900℃, being significantly lower than that of GCr15. The tensile strength of the HS was 460MPa after thermal refining with brittle fracture.
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