Fine Microstructure of Novel Microdistortion Gear Steel

In order to reduce quench deformed of car gear, a new kind of microdistortion gear steel is developed and its fine microstructure is discussed by SEM. The results show that the tested steel can obtain carbide free bainitic ferritic laths with fine microstructure under air-cooling condition. The bainitic ferritic laths, sublaths and subunits are surrounded by retained austenite, which can insure the gear steel possesses high strength and toughness, the impact toughness has increased remarkably. The good mechanical performance of the steel can meet the service demands of the gear.     

农机耙片用新型铸态贝氏体钢的组织与耐磨性

为改进耙片的材质和工艺，研制出一种新型铸态贝氏体钢，采用液态挤压铸造使耙片一次成形，以代替原65Mn钢及传统生产工艺。该铸态贝氏体钢通过合金化和控制冷却速度的方法，不需热处理而在铸态下直接得到贝氏体组织和所需性能。试验结果表明，新型铸态贝氏体钢的耐磨性明显优于热处理后65Mn钢。其洛氏硬度为46～50HRC，冲击韧性αk≥26J／cm^2，对65Mn钢的相对耐磨系数为1．29。     

高硅固溶强化铁素体球墨铸铁在汽车铸件上的应用实践

本文通过高硅固溶强化铁素体球墨铸铁的方法,获得了高强度、高韧性、硬度更均匀的汽车球铁铸件,降低了合金化球铁件的成本。实践证明,批量产品加工后得到加工厂家好评。