Surface Treatment Effects on Aermet 100 Steel: Part 1. Shot Peening Effect onCorrosion and Fatigue of Aermet 100 Steel

摘要

This study was conducted to identify the effect of shot peening on the corrosionand fatigue behavior of AerMet 100 steel. The specimens were shot-peened with hard cast steel shot, and the induced residual stress profile was determined with the aid of X-ray diffraction. Subsequently, the specimens were undergone to direct tension stress corrosion and immersion corrosion in an aqueous 3.5% NaC1 solution, salt spray corrosion in two separate fog chambers for atomized aqueous 5% NaC1 solution with and without SO2 gas, and fatigue test in a laboratory environment. The shot peening induced a residual compressive stress 1,130 MPa at 0.03 mm depth in the specimen. The shot peening did not change the susceptibility of AerMet 100 steel to stress corrosion, but reduced the resistance to immersion corrosion and salt spray corrosion. This unfavorable effect is associated with the surface cold work and greater exposure area generated by the shot peening process. On the other hand, the shot peening extended the fatigue life of AerMet 100 steel.