含Ni高强度灰铸铁的生产工艺

Production Process of High-strength Gray Iron Containing Ni

详细阐述了含Ni高强度灰铸铁的试验方法,生产结果显示:试样的石墨形态为A型,石墨大小为4级,珠光体体积分数为95%;φ20 mm的试样的抗拉强度平均值为324 MPa,硬度平均值为216 HBW;50%存活率时其拉压疲劳极限约为95 MPa,满足技术要求。总结了提高灰铸铁性能的主要措施:(1)在炉料熔炼时,增加Si C进行熔炼,促进铁液凝固时的形核生成;(2)增加孕育量和改变二次孕育处理方式,有利于细化石墨,增加石墨数量,提高材料性能;(3)优化铁液中的C、Si、Cu、Mo、Sn元素,同时在铁液中加入Ni,可提高材料的力学性能。

The test method for high-strength gray iron containing Ni was described in detail. The production results showed that the graphite state of the sample was type A,the size of graphite was grade 4 and the volume fraction of pearlite was 95%. The tensile strength of the specimen with 620 mm was 324 MPa on average and the average hardness was 216 HBW. The tensile fatigue limit was about 95 MPa under 50% survival rate ,which satisfies the technical requirements. The main measures fbr improving the perfbn31ance of gray iron were summarized as fbllows： （1）When smelting,the amount of SiC was increase fbr smelting to promote nucleation during solidification of molten iron. （2）Increase inoculation amount and change of secondary inoculation treatment. They were beneficial to refine the graphite ,increase the amount of graphite and improve the properties of the material. （3）Optimize the C,Si, Cu, Mo,Sn elements in the molten iron and add Ni in the molten iron to improve the mechanical properties of the material.