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研究了球墨铸铁表面等离子束熔凝硬化区的组织和性能。结果表明:工作电流达50 A时可实现球墨铸铁表面的微熔硬化处理;工作电流增大,熔凝层和硬化层的深度、宽度增加,硬度值降低;熔凝硬化后,熔凝区石墨相消失,组织为细小的变态莱氏体+残余奥氏体,相变硬化区的组织为隐针马氏体+残余奥氏体+球状石墨+铁素体;过渡区出现包围石墨球的双壳组织,对提高耐磨性有利;沿硬化层深度方向显微硬度先降后升,达到最高值后又缓慢下降。
The microstructure and properties of the plasma hardened zone on the surface of ductile iron were studied. The results show that the micro-hardening of the surface of ductile iron can be achieved when the working current reaches 50 A; the working current increases, the depth and width of the fused layer and hardened layer increase, and the hardness decreases; Disappeared, the organization for the small metamorphic ledeburite + retained austenite, the transformation hardening zone of the organization hidden pin martensite + retained austenite + spherical graphite + ferrite; transition zone appears around the double Shell organization, to improve the wear resistance of the beneficial; along the depth of the hardened layer microhardness first down and then rise to reach the highest and then slowly decline.