汽车发动机缸体灰铸铁等离子相变硬化组织及性能分析

Analysis of Structure and Properties of Plasma Phase-change Hardening for Automobile Engine Body

采用等离子相变硬化设备对汽车发动机缸体灰铸铁进行了表面相变硬化处理,分析了处理后铸铁的显微组织和硬度特征。结果表明,相变硬化处理后的灰铸铁分三个区,即熔化区、固态相变区和热影响区,熔凝层的组织是细小的莱氏体。处理后的表面硬度有显著提高,并明显提高了发动机缸体的耐磨性和使用寿命。

Grey cast iron of automobile engine body is treated （phase-change hardening） by plasma surface heat treatment.The microstructure and microhardness of grey cast iron was analyzed.The experiment results show that the microstructure consists of melting zone,phase-change hardening zone and thermal-effect zone.The microstructure with ledeburite is formed in the melt-solidified hardening layer. The microhardness treated by plasma heat treatment is notably improved, and the wear resistance and operating life increase obviously.