Tribological Characterization of Electrolytic Hard Chrome Coatings

Abstract

Electrochemical chromium plating is one of the most widely used surface treatments for metallic materials. This treatment results in a surface layer highly resistant to mechanical wear, temperature and corrosion. In this paper, the experimental material is in the form of a tube made of AISI 304 stainless steel, on the surface of which chromium layers have been deposited by three different companies dealing with electrochemical plating. Tribological tests were performed on a UMT Tribolab device with dry friction of balls made of AISI 52100 steel and ZrO 2 ceramics, both with a diameter of 4.762 mm. Measurements were performed at different loads. In the experiments, the courses of friction coefficients were evaluated, and after the measurement, the amount of material removed during friction was determined from the cross-sections of the formed grooves. Furthermore, the influence of the hardness of individual chromium layers and counterparts on tribological behaviour was investigated. The hardness of the counterpart proved to be important, since in the case where the counterpart is softer than the surface layer, the wear was greater than in the opposite situation.