Influence of casting skin on the fatigue lifetime of ferritic ductile cast iron

Abstract The fatigue behavior of cast iron is usually investigated on machined specimens. Components of cast iron, however, have a casting skin. Therefore, the investigation of the influence of the casting skin on the lifetime is of interest. To study this influence, isothermal fatigue tests were carried out on heat resisting spheroidal graphite cast iron EN GJS SiMo 4.05 in 4-point bending setup at 400 °C. Specimens with and without casting skin were investigated comparatively. The number of cycles to failure was significantly lower for specimens with casting skin. Metallographic investigations underline the reduction of lifetime caused by casting skin.