Effect Of Heat Treatment On Microstructure And Properties Of High Chromium White Cast Iron

High chromium white cast iron is the third-generation white cast iron after the ordinary white cast iron and Ni-hard cast iron.Due to high hardness M7C3 eutectic carbides and high chromium content,it has higher toughness, heat resistance and wear resistance than ordinary cast iron. At present, high chromium white cast iron has been widely used in mining, cement, electricity and other industrial fields.Chemical composition of high chromium white cast iron material have been identified on the basis of the actual use condition requirements and failure mode of the grinding ball in this article.The effect of heat treatment on microstructure and properties of high chromium white cast iron has been researched by destabilization treatment,and the heat treatment process optimization has been studied in the light of these conclusions to improve the anti-wear properties of high chromium white cast iron by solution and aging treatment.The results show that:the microstructure of high chromium white cast iron (1.97C%,18.12%Cr) by destabilization treatment (950~1050℃) can occurs martensite transformation,and has higher hardness.The sample heating 1010℃for 4h has highest hardness(HRC59).Impact toughness of the material increases with temperature increase.The impact toughness of material can be improved by tempering,but lower hardness.During in load 50N,for 4h sliding wear,The sliding wear mechanism of as-cast high chromium white cast iron is adhesive wear and abrasive wear, when the material have higher hardness(﹥56HRC)and lower toughness(﹤4.96 J/cm2),the wear mechanism is mainly fatigue wear,when the material have good co-ordination between hardness(55HRC or so) and toughness(﹥5.12 J/cm2),the wear mechanism is mainly abrasive wear.High chromium white cast iron materials has good anti-wear properties by grading heat treatment.The wear weight loss of the high chromium white cast iron material by grading heat treatment (1050℃+950℃) and tempering treatment (400℃) was 0.5 times of cast,0.76 times of 1010℃+400℃,0.66 times of high chromium white cast iron(2.84C%,27.12Cr).