Explanation

Also known as modified cast iron. Hypoeutectic high strength grey cast iron whose microstructure and mechanical properties have been improved by inoculation of iron liquid. Since the flaky graphite in ordinary cast iron has a splitting effect on the matrix of cast iron, and causes stress concentration at the tip of graphite flake, which greatly reduces the strength of cast iron, it is required to refine graphite as much as possible and reduce graphite precipitation. The addition of inoculant can promote the formation of a large number of crystal nuclei during the eutectic solidification process, thus refining the eutectic cluster and graphite, making graphite spheroidize appropriately (generally in the form of floccules), and generally making the matrix structure easy to transformation into pearlite. The commonly used inoculant is granular ferrosilicon. The tensile strength is generally 200-400MPa, the bending strength is 450-600MPa, and the compressive strength is 1000-1300MPa. It is widely used in high-strength castings such as cast iron pipes, pump bodies, etc.

Classification