Optimization of process parameters for deposition of Stellite on X45CrSi93 steel by plasma transferred arc technique

The characteristics of Stellite F coatings, deposited on automobile engine valves made of X45CrSi93 steel, with reference to the defect level, dilution, microstructure and hardness as a function of operating parameters viz., plasma gas flow rate, powder flow rate, pre-heat and current intensity are addressed in this work. Higher current levels has resulted in higher dilution levels and also melting/burning of the substrate. The use of pre-heat was helpful in accomplishing crack-free deposits, especially in continuous production runs. The optimized parameters could successfully be employed in the production line for the manufacture of Stellite coated engine valves for automotive applications.