Effect of Residual Stress and Microcracks in Chrome Plating Layer to Fatigue Strength of Axle-Shaped Machine Parts

摘要

Chromium plating is used widely in industry to enhance wear, abrasion resistance and to restore the dimensions of undersized parts. However, tensile residual stress always exists in chrome layer because of hydrogen embrittlement so it affect to mechanical properties of the chromium plating machine element, especially in fatigue strength. In this paper, effect of residual stress together with microcracks in chrome plating layer to the fatigue strength was studied. The sample (AISI 1045 steel) was plated with 10 and 60 micrometers thicknesses and residual stress in chrome plating layer was determined by X-ray diffraction technique (Cu-Kα radiation). The results showed that as chromium layer thicknesses increased, tensile residual stress decreased and microcrack density increased. Consequently, the fatigue strength went down when chromium layer thicknesses increased.