Properties of laser-cladded stellite coatings prepared on preheated chromium steel

A clear dependence of the micro-cracking susceptibility on the base preheating temperature is observed for stellite coatings prepared by direct laser melting of metal-powder on the preheated chromium steel. The number of cracks decreases with the preheating temperature and for preheating above 650 °C no cracks are observed. This behaviour is consistent with numerical calculations. The observed deterioration of the corrosion and wear resistances of the coating with increase of the base preheating temperature is ascribed to the temperature dependent migration of Fe from the substrate into the coating.