The high humidity of marine atmosphere and the existence of corrosive chloride ions lead to the premature corrosion failure of aluminum alloy components. The development of surface-strengthening technology provides an opportunity to prolong their service life spans. As a mature surface-strengthening technology, the shot peening process is widely used, owing to its advantages over other strengthening technologies, including its easy operation and high production rate. The shot-peened surface integrity depends on shot peening variables that introduces the thermomechanical effect to the deformed surface layer. When the inappropriate shot peening parameters are adopted, the shot-peened surface integrity could be deteriorated, which further weakens the corrosion performance of the surface. Therefore, it is essential to optimize shot peening process variables with the consideration of the material and its application. In this paper, the strengthening mechanism of the shot peening process was firstly elaborated, and then the effects of process parameters on the surface integrity of aluminum alloy were reviewed. The relationship between the surface integrity and corrosion resistance was also revealed. Two directions, including the application of the surface temperature rise during the shot peening process and the shot-peened surface roughening, are proposed.

2024 aluminum alloy is an engineering equipment material with broad application prospects, which can be used in space flight and shipbuilding industry. However, the lack of corrosion resistance hinders its further application. The effects of milling and further shot peening processes on the surface integrity of 2024 aluminum alloy were investigated. Electrochemical polarization measurements were performed in 3.5wt% NaCl solution to characterize the corrosion resistance of milling alone surfaces and the further shot-peening process surfaces after milling. Experimental results reveal that the surface residual stress and microhardness of the shot-peened surfaces are much higher than those of the only milling surfaces owing to the severer plastic deformation induced by further shot peening process. While the shot-peened surfaces are roughened with the higher surface roughness. Under the synergic effects of three terms mentioned above, the corrosion potential of shot-peened surfaces is much positive than that of milled ones, meaning the corrosion resistance after shot peening is better. The comparison test gives a way to enhance the corrosion behavior of 2024 aluminum alloy milled surfaces.