Influence of heat treatment on the microstructure of synthetic nodular cast irons

Abstract

The article deals with the influence of charge composition on the microstructure and mechanical properties of synthetic nodular cast irons after casting and after heat treatment (ferritizing annealing and isothermal heat treatment). The paper shows a comparison of the microstructure of nodular cast irons with the graded amount of steel scrap in a charge. The chemical composition of individual meltages was regulated alternatively by ferrosilicon (FeSi) and carburizer or metallurgical silicon carbide (SiC). The results of the experiments show that the SiC additive positively influences the microstructure as well as the mechanical properties of nodular cast iron, especially in specimens from the meltages with a higher ratio of steel scrap in the charge. Moreover, the production of synthetic nodular cast irons with a SiC additive is economically advantageous.