共晶碳化物形貌与分布对白口铸铁抗冲击磨料磨损性能的影响

Effect of Morphology and Distribution of Eutectic Carbide on Impact Abrasive Wear Resistance of White Cast Iron

通过变质控制共晶碳化物的形貌与分布，采用圆度面积分数定量地描述共晶碳化物的形貌组成，研究了共晶碳化物形貌与分布对白口铸铁抗冲击磨料磨损性能的影响。结果表明，磨损面上的共晶碳化物网状结构由于直接经受磨粒冲击而易被冲断。磨损面脆断现象的发生与网状共晶碳化物的比例数密切相关。团块状共晶碳化物有易脱落倾向。断网状共晶碳化物表现出良好的抗磨性。讨论了不同形貌的共晶碳化物的作用机制。

The morphology and distribution of the eutectic carbide in white cast iron are controlled by modification treatment in this paper,and a parameter which is defined as roundness area fraction is used to quantitatively describe the morphology and the distribution of the carbide. This makes it possible to investigate the effect of the morphology and distribution of the eutectic carbide on impact abrasive wear resistance of white cast iron. It is shown that under the experimental conditions (the real impact work is about 13. 29 J/cm2),fracture of the wear surface of the specimen is closely related to the proportion of the networked eutectic carbide in the microstructure. Blocky eutectic carbides are found to readily fall off from the matrix during the wear process. Controlling the proportion of the networked eutectic carbide can lead to a safe and reliable microstructure with high impact abrasive wear resistance