Thermal fatigue analysis of stellite coated P20 tool steel

Thermal fatigue failure is one of the main reasons for the mechanical failure in Die casting die materials. To improve the fatigue strength of the material, one of the most used method is surface treatment of the materials in which hardness and die life is improved. This paper reports an investigation of the performance of AISI P20 tool steel, coated with Stellite 6 alloy with varying coolant positions and coating thickness. Results on thermal fatigue behaviour of P20 tool steel studied in a newly designed specimen. The bottom surface of a test sample was heated in molten aluminium bath at constant temperature 600°C and coolant flow positioned inside the specimen. The fatigue analysis was evaluated on above specimens made of P20 material and heat cracks and thermal fatigue behaviour were studied. By varying the coolant locations and coating thickness, results were evaluated and optimizes the parameters. The main objective is to prolong the formation of thermal cracks on die, so that increased die life shall be expected. Based on fatigue failure theories of stress-life theories such as; Goodman and Gerber, this paper predicts the fatigue life, damage and alternating stress of a designed component with varying coolant position with different level of coating thickness were studied.