Effects of surface alloying on microstructure and wear behavior of ductile iron

In this research, the effect of austenitic stainless steel cladding on improving the wear behavior of ductile iron was studied. Samples made of ductile iron were coated with steel electrodes (E309L) by manual shielded metal arc welding. The effect of coated layer thickness on microstructure, hardness, and wear resistance of the surface were investigated. Wear resistance of the samples was measured using the pin-on-plate technique. Optical microscopy and scanning electron microscopy were used to investigate microstructure and wear mechanisms. The phases in the interface of both the coating and the substrate were studied by X-ray diffraction. The results showed that a film of white chromium-enriched iron formed at the interface between the substrate and coating which contained iron–chromium complex carbides. It was, therefore, concluded that enhanced properties would be obtained if the coating thickness and the carbides deposited on the surface were reduced. In samples with a thin coating, surface hardness rose to above 1150 HV (five times higher than that of the substrate) and wear resistance increased significantly.