低合金球墨铸铁活塞材料的显微组织及其摩擦磨损性能研究

Study on Friction Properties of Low Alloyed Nodular Cast Iron Piston Materials

采用铸造成形方法,以QT600-3成分为基础,通过添加元素Cr/Ni/Mo制备了含有少量合金元素的马氏体球墨铸铁活塞材料,并与传统合金灰铸铁和QT600-3材料微观组织进行对比分析,同时采用环-块式摩擦磨损试验机进行室温干磨试验。结果表明:研发的两种球墨铸铁材料的耐磨性分别较传统合金灰铁、QT600-3材料分别提高了6.5%、51.7%和17.0%、57.1%,且具有较低摩擦系数;材料的磨损失效机理主要为黏着磨损,研发的球铁材料由于添加了少量的合金元素,能在基体组织中析出大量碳化物,大幅提升材料的耐磨性,并且减轻了磨损表面的氧化程度,满足了低成本、高性能的应用要求。

Martensitic nodular cast iron piston material containing a small amount of alloy elements was prepared by casting method based on QT600-3 composition and adding Cr/Ni/Mo.The microstructure was compared with that of traditional alloy gray cast iron and QT600-3 material.At the same time,the dry grinding test at room temperature was carried out by ring block friction and wear tester.The results show that the wear resistance of the two nodular cast iron materials is 6.5%,51.7%and 17.0%,57.1%higher than that of traditional alloy gray cast iron and QT600-3 respectively,and have lower friction coefficient.The wear failure mechanism of the material is mainly adhesive wear.Due to the addition of a small amount of alloy elements,the developed ductile iron material can precipitate a large amount of carbides in the matrix structure,greatly improve the wear resistance of the material,reduce the oxidation degree of the wear surface,and meet the application requirements of low cost and high performance.