Abrasion-Resistant White Cast Iron ASTM A532_A532M

5.3 Rational selection of matrix structure of high chromium white cast iron

First of all many manufacturers prefer to choose the tempered martensite when choosing the matrix structure of high chromium white cast iron. No matter the working condition and the stressful state of the castings. Even the less the retained austenite in the matrix is better. The retained austenite can be regarded as a defect of the structure. And even as the standard of the product’s disqualification.

The research results show that the wear behavior of the matrix is different in different wear systems. As a result, we can select the matrix according to the wear characteristics and the stress state of the parts. That is so as to maximize the potential of the material.

The test results show that the martensitic matrix displays the best abrasion resistance under low-stress abrasive wear conditions. No matter it is high chromium white cast iron or medium chromium white cast iron. Followed by martensite + bainite + austenite complex matrix. Then it is bainite + austenite. And probably the worst is austenite.

The results of the field assessment confirmed this conclusion. Martensite + bainite + austenite complex matrix of medium chromium white cast iron grinding ball shows the best wear resistance on the gold ball mill. And also shows the minimum crushing rate. Analysis of wear morphology shows that grinding ball wear belongs to abrasive wear which is mainly fatigue peeling mechanism. In conclusion, improving the anti-fatigue ability to grind balls is the best way to improve wear resistance and reduce the crushing rate of grinding balls.

The results of the wear surface analysis show that in the martensite + bainite + austenite matrix. Maybe the impact fatigue exfoliation is obviously smaller than the martensite matrix. Furthermore, the microcrack is smaller than the martensite. Which is related to the distribution of martensite + bainite + austenite basic tissue. It seems like it is easy to produce the crack initiation of carbide.