C、Si、Mn、Cu对中锰球墨铸铁组织和性能的影响

Effect of C, Si, Mn and Cu on Microstructure and Mechanical Properties of Medium Manganese Nodular Cast Iron

应用湿砂铸型浇注中锰球墨铸铁,采用正交设计研究了C、Si、Mn、Cu对中锰球墨铸铁组织和力学性能的影响。结果表明,中锰球墨铸铁的铸态组织为奥氏体+碳化物+球状石墨,扫描照片中可见有大量细小均匀的韧窝。中碳、高硅、中锰和低铜有利于提高中锰球墨铸铁的硬度;低碳、高硅、中锰和中铜有利于提高其冲击韧度;低碳、中硅、低锰和低铜有利于提高其耐磨性。新开发的中锰球墨铸铁的硬度、冲击韧度和耐磨性远高于目前生产排沙潜水泵过流部件中所使用材料的各项性能,使用寿命是其2倍左右。

The medium manganese nodular cast iron was poured in the green sand mould and the effect of C, Si, Mn and Cu on the microstructure and mechanical properties of medium manganese nodular cast iron were studied by means of orthogonal test. The results show that the as-cast structure of medium manganese nodular cast iron consists of austenite, carbide and spherical graphite. TEM analyses show that there are a lot of tiny uniform dimples. The results also reveal that medium carbon, high silicon, medium manganese and low copper is helpful to increase the hardness of medium manganese nodular cast iron; and low carbon, high silicon, medium manganese and medium copper contribute to the improvement of its impact toughness, whereas high carbon, medium silicon, low manganese and low copper is useful to increase its wear resistance. The newlydeveloped medium manganese nodular cast irons has better hardness, impact toughness and wear resistance than those of the materials which are currently used in the production of overflowing components of scouring diving pump and the operating life can be improved by two times.