Coating effect on the fatigue strength of a free cutting steel

Abstract

This paper deals with the effect of electrodeposited zinc and nickel coatings on the fatigue strength of a free cutting steel. This class of materials is frequently used in the mass production, due to their good machinability, in order to reduce the production costs. Moreover, free cutting steels often operate under high wear conditions, for instance in sliding components. Therefore, suitable coatings are usually applied to improve their tribological response. In addition, in many industrial applications, free cutting steels must withstand significantly high fatigue loads, even in corrosive environment. In order to assess the fatigue response, S–N curves and endurance limits at run-out of specimen sets with different features were determined. The tests involved samples with different coatings and plain geometry for comparison purposes. The experimental results, properly set up by tools of Design of Experiment, were statistically processed and compared. The outcome was that no significant difference in terms of fatigue strength between the three specimens set was encountered. It implies that coatings can be suitable to enhance wear resistance without detrimental effects on fatigue.