WC颗粒增强钢基表层复合材料中增强相和组织的演化

Evolution of Reinforcing Phase and Microstructure in WC Particle Reinforced Steel Matrix Composites

运用“复合剂技术”制备了WC颗粒增强钢基表层复合材料,系统研究了颗粒尺寸对WC颗粒在复合材料组织中的存在形态及复合材料组织变化的影响规律.结果表明:WC颗粒溶解于高温钢液,微区内W、C元素的含量显著提高,存在合金元素的相互扩散和迁移;当加入的WC颗粒直径小于100μm时,WC颗粒不再以原有的形态发挥硬质相的作用,而是形成新相(W,Fe)7C3型碳化物来发挥硬质相的作用,最终在铸钢基体的表面形成高碳高钨的白口铸铁组织.

The WC particle reinforced steel matrix composites were fabricated with the promoter technique. The state of WC particles in WC particle reinforced steel matrix composites and the effect of WC particle size on microstructure were investigated. The results show that the WC particles partially dissolve in the liquid of steel, and the C and W contents substantially increase in the matrix close to the bonding surface, indicating that the alloy element diffusion and transformation occur. For the WC particle size smaller than 100 μm, the WC particles do not remain their original state in the composite but become free cementite（W, Fe）7 C3 to reinforce the steel matrix. The microstructure consists of pearlite and free cementite （W,Fe）7 C3, and a layer of white cast iron forms on the surface of steel finally.