C、Cr、Si、Mn对低铬白口铸铁组织和力学性能的影响

Effect of C、Cr、Si、Mn on the Structure and Mechanical Properties of Low Chromium White Cast Iron

应用湿砂铸型浇注低铬白口铸铁,采用正交试验研究了C、Cr、Si、Mn对低铬白口铸铁组织和力学性能的影响。结果表明:含碳量2.4%和2.7%时碳化物基本上是呈网状分布的,形成了离异共晶的网状碳化物组织;而含碳量3.0%时,离异共晶组织不再出现。高碳、低硅、高铬和低锰有利于提高硬度;低碳、低硅、中铬和高锰有利于提高冲击韧度;高碳、低硅、低铬和高锰有利提高耐磨性。新开发的低铬白口铸铁的硬度、冲击韧度和耐磨性远高于目前在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5倍左右。

The low chromium white cast irons were casted in the green mould and the effect of C, Cr, Si and Mn on the structure and mechanical properties of low chromium white cast iron was studied by orthogonal test. The results show that the carbides are basically distributed in a netlike form with 2.4wt% Cand 2.7wt% C and the divorced eutectic carbide with netlike structure is formed. When the carbon content is 3.0wt%, the divorced eutectic netlike carbides disappear. The results also reveal that high carbon, low silicon, high chromium and low manganese are beneficial for increasing hardness, and low carbon, low silicon, medium chromium and high manganese contribute to improving impacting toughness, whereas high carbon, low silicon, low chromium and high manganese contribute to increasing wear resistance. The new developed !ow chromium white cast iron has better hardness, impacting toughness and wear resistance than those of the materials used in overflowing components of scouring diving pump, and the operating life can be improved by around five times.