Dependance Between Charge Composition and Fatigue Properties of Nodular Cast Irons

Abstract

The contribution deals with comparison of microstructure and fatigue properties of synthetic nodular cast irons. The basic charge of experimental meltages was formed by the different ratio of pig iron and steel scrap. The chemical composition of individual meltages was regulated alternatively by carburizer and ferrosilicon (FeSi) or metallurgical silicon carbide (SiC). The fatigue tests were run at high-frequency sinusoidal cyclic push-pull loading (frequency f » 20 kHz, load ratio R = –1, temperature T = 20 ± 5 °C) using the ultrasonic testing equipment KAUP-ZU. The paper shows the influence of charge composition on microstructure, fatigue properties and micromechanisms of failure.