The Main Reasons For Breaking Wear-resistant Grinding Steel Balls

1. In the production process of wear-resistant Grinding Steel Balls, due to the lax management of scrap steel, inferior scraps are mixed, especially the content of low melting point metal materials such as lead and zinc exceeds the standard and is easily broken.

2. The gas content in the molten iron is high, the charge is wet, the moisture is decomposed into hydrogen and oxygen at high temperature, and the deoxidation is not performed before pouring, or the casting exhaust is not good, thereby generating pores in the casting ball and reducing the strength of the casting ball.

3. During the pouring process, molten iron and iron slag are not separated, resulting in slag holes in the casting ball and reducing the strength of the casting ball.

4. Heat treatment process The heat treatment process is incorrect or not strictly implemented, the stress of the casting ball is not eliminated, the metallographic structure of the high chromium ball is unreasonable, and the retained austenite is too high. At present, the retained austenite of high chromium balls in the air quenching process is generally 15%-30%. During use, austenite transforms into martensite, volume expands, and internal stress increases. Steel balls are peeled off during impact and wear. Generally, this phenomenon is more serious after 900-1000 hours of use in the mill.

5. The chemical composition is unqualified. There are many kinds of steel ball materials with unqualified chemical composition, including low chromium balls, medium chromium balls, high chromium balls and extra high chromium balls. In addition, there are austenitic ductile iron balls and martensitic ductile iron balls. Each ball has a different chemical composition standard. Qualified chemical composition is the most basic requirement for the quality of steel balls, and unqualified chemical composition will directly affect material properties.