First, anti-wear high-chromium cast iron composition and role
1. Carbon and chromium
The main role of carbon and chromium is to ensure the number and shape of the carbide in the cast iron. As the content of C increased, the amount of carbides increased. With the increase of Cr / C ratio, the morphology of eutectic carbides changed from continuous network to flake to rod. The eutectic carbide The crystal type undergoes the change of M3C → M3C + M7C3 → M7C3. Data indicate that: when the eutectic carbide unchanged, and Cr / C is 6.6 ~ 7.1, high chromium cast iron crack resistance to expand the strongest. According to these principles, it is appropriate to measure C as 3.1% ~ 3.6% and the content of Cr as 20% ~ 25%. The matrix of Cr can also improve the material's hardenability.
Its role is to increase the hardenability of high chromium cast iron, inhibit the austenite matrix to pearlite transformation, and promote the formation of martensite matrix.
Its role is to refine the grain, improve hardness, increase wear resistance.