Effect of a Shot Peening Pre Treatment on the Fatigue Behaviour of Hard Chromium on Electroless Nickel Interlayer Coated AISI 4340 Aeronautical Steel

Abstract

Multiple layer systems of coatings are considered to have larger resistance to crack propagation in comparison to coatings with simple layer. With regard to fatigue, it is possible to improve the resistance of a component with the application of shot peening treatment, whose compressive residual stresses delay or eliminate the initiation and propagation of fatigue cracks. The aim of this study is to analyse the effects on rotating bending fatigue behaviour of hard chromiumelectroless nickel multilayer system coated AISI 4340 high strength steel submitted to shot peening pre treatment. Results indicated that the interaction between the shot peening process with the multilayer system was not satisfactory, resulting in intense delamination. Fracture surface analysis by SEM was performed toward to identify the fatigue crack origin, as well as the coatingsubstrate delamination process.

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

“…Many researches has investigated the effect of chromium plating on fatigue life of high strength steel. The tensile residual stress in chrome plating layers are relieved by local microcrack during electroplating [2]. According to Hammond and Williams, the magnitude of tensile stress varies depending upon the plating solution and operating conditions [3].…”

Fatigue strength improvement of a hard chromium plated AISI 4140 steel using a plasma nitriding pre‐treatment

“…This micrograph indicates that cracks may grow from the free surface of the coating layer into the interface and then into the substrate. According to Nascimento et al 24 , it is likely that the fatigue crack may propagate through interface inside the substrate if the coating layer is brittle and the substrate ductile. Similar findings concerning crack growth from the micro-crack to the interior region have also been reported by others.…”

Salt-Fog Corrosion Behavior of GCr15 Steels Treated by Ultrasonic Strengthening Grinding Process

“…As an alternative, mechanical strengthening has emerged as a promising solution to obtain a good corrosion resistance for metals, mainly due to the chilled layer and compressive residual stress microstructures formed on metal surfaces after surface treatment [26][27][28], which results in the improvement of fatigue life. So far, mechanical strengthening techniques, such as shot peening (SP) [29,30] and rolling finishing [31,32] have been proposed extensively for corrosion resistance investigation of metals.…”