A high-performance and low cost nitrogen-containing gray cast iron

Abstract

To meet the demand for high-strength gray iron castings while lowering casting production costs, nitrogen micro alloyed gray cast iron with manganese nitride inoculant was developed, and the effects of manganese nitride addition on its microstructure, mechanical properties, and casting cost were investigated. The test results show that with different manganese nitride additions, the graphite flakes have round and blunt ends and short, thick, and slightly curved shapes; as the nitrogen content in the iron increases, the graphite forms become shorter and curved, and the pearlite content increases, which is conducive to improving the strength and hardness of gray cast iron. Excess nitrogen content in castings causes nitrogen porosity defects, which significantly degrades the material properties. The addition of alloying elements such as Cu and Sn can be reduced by adding an appropriate amount of manganese nitride to the process, and the casting cost can be reduced by 180 RMB/ton to realize low-cost production of high-performance gray cast iron.