材料复合视角下的高铬铸铁组织结构

高铬铸铁可以看成是由增强相和基体相组成的颗粒增强复合材料,从材料复合的角度对高铬铸铁磨料磨损进行了分析。结果表明:高铬铸铁中碳化物保护基体减少受磨料冲击和磨损,基体固定和支撑碳化物以免碳化物失稳或被拔出;碳化物尺寸太小容易被冲断或被连根挖出,尺寸太大脆断倾向大;碳化物间距过大,磨料落在基体上的机率增大,间距过小时又使得基体难于固定和支撑;碳化物体积分数过小不耐磨,过大会使基体过于弱化;不同组织类型的基体性能差异很大,其中马氏体基体最耐磨但韧性差。结合分析结果,综述了高铬铸铁中碳化物和基体的主要控制方法。

Microstructure of High Chromium Cast Iron Under the Perspective of Composite Material

High chromium cast iron may be considered as a particulate reinforced composite which consists of matrix materials and reinforced phase. Abrasive wear of high chromium cast iron was analyzed from the perspective of materials composition. The results show that the carbides in high chromium cast iron protect the matrix from abrasive impact and wear, and the matrix fixes and supports the carbides to prevent the carbides from instability or being pulled out. The size of carbide is too small and it is easy to be cut off or dug out by connecting roots. If the carbide spacing is too large, the probability of abrasive falling on the matrix increases, and if the carbide spacing is too small, the matrix is difficult to be fixed and supported. Carbide volume fraction is too small to wear, too large to make the matrix too weak;The matrix properties of different structure types vary greatly, among which martensite matrix is the most wear-resistant but has poor toughness.