Fatigue of nodular cast iron at high frequency loading

Abstract

The paper deals with the influence of charge composition on microstructure of nodular cast iron and its fatigue properties at high frequency loading. The basic charge of experimental melts was formed by a different ratio of pig iron and steel scrap. Chemical composition of individual melts was regulated alternatively by metallurgical silicon carbide (SiC) or ferrosilicon (FeSi) and carburizer. Fatigue tests were realised at high frequency sinusoidal cyclic push‐pull loading (stress ratio R = –1) at ambient temperature (T = 20 ± 5 °C). High frequency fatigue tests were carried out with using of the ultrasonic fatigue testing device KAUP‐ZU (frequency f ≈ 20 kHz).The results show differences in mechanical and fatigue properties, which are connected with the microstructure. SiC additive positively influences microstructure and consequently, mechanical and fatigue properties of nodular cast iron are improved.