Direct laser cladding of stellite coatings and selection of process parameters

The direct laser cladding technique is applied for preparation of Co-based stellite SF6 protective coatings on the chromium steel base of a composition designed for the steam turbine blades. The cw 1.5 kW CO2 laser stand equipped with the multi-stream nozzle characterized by a powder feeding coaxial with the laser beam is used. It is observed that the increase of the base preheating temperature and the average temperature of the coating reduces the cracking susceptibility of the laser clads. This is accompanied by the decrease of the corrosion and wear resistances.Peer Reviewe