化学成分对耐磨铸钢组织与性能的影响

Effect of Chemical Compositions on Microstructure and Properties of Wear-Resistant Casting Steels

为了克服高锰钢作为履带板材料具有的耐磨性能较差、力学性能较低的缺点,设计了能够作为高锰钢替代材料的一种新型双相(马氏体+贝氏体)耐磨铸钢.研究结果表明:试验钢在淬火回火态下为马氏体+贝氏体双相组织,另外还残存着极少量的残余奥氏体组织.含碳量的增加使试验钢的冲击韧性和延伸率趋向降低.随着铬含量的升高,冲击韧性在淬火回火态下升高.含质量分数为0.30%C,0.6%Cr合金的综合力学性能最优,组织为马氏体+贝氏体双相组织.经由400 h磨损试验后,在干态磨损条件下,其耐磨性能比高锰钢提高了56%,而在有腐蚀介质的湿态磨损条件下,耐磨性能比高锰钢提高了22.5%.

A novel dual-phase（martensite plus bainite） wear-resistant casting steel for caterpillar band was designed and tested to overcome the shortcomings of high-Mn steel,such as the low mechanical properties especially the wear-resistant properties.The results showed that the microstructure of the specimens consist of martensite and bainite with the least amount of residual austenite after quenching tempering.With the increasing carbon content in specimen,its elongation and impact toughness tend to decrease,while the impact toughness remained increasing after quenching and tempering with increasing Cr content.Comparatively,the best mechanical properties belong to those specimens in which the carbon and chromium contents are 0.30% and 0.60%,respectively,with the bainite dual-phase structure.After the grinding test for 400 h,the casting steel specimens show the wearability which is 56% higher than high-Mn steel under dry friction conditions and 22.5% higher than high-Mn steel under wet friction conditions involving corrosive medium.