Influence of Surface Integrality on Corrosion Resistance of 40Cr Steel
The changes of surface integrality caused by electrical discharge strengthening and shot peening were investigated and their influences on corrosion resistance of 40Cr steel were determined.Corrosion resistance of specimens was evaluated by 500 h salt spray testing on normal atmospheric temperature and by electrochemical performance.The results show that the microscopic structure of the specimens' surface improves;the residual stress and microscopic crack are created after electrical discharge strengthening and shot peening on 40Cr steel.The corrosion resistance of the shot-peened specimens is lower than the corresponding corrosion resistance of the unstrengthened specimens and the corrosion resistance of the electrical discharge strengthened specimens is obviously higher than that of the unstrengthened specimens and the shot-peened specimens.