Hydrogen Embrittlement of Dissimilar Steel Welding Joints

Aiming at the problem of hydrogen embrittlement in dissimilar steel welded joints, the hydrogen permeation behavior and stress corrosion sensitivity of the material in sea water were studied by hydrogen permeation test, electrochemical test and slow strain rate tensile test (SSRT), and the fracture morphology was observed with SEM. The results show that the corrosion resistance and hydrogen permeation characteristics of dissimilar steel welded joints are obviously different. The corrosion resistance of the weld zone is between two parent materials. The corrosion resistance of A side HAZ is the worst, and hydrogen evolution reaction is easy. Under the condition of different polarization potential, the material gradually changes from ductile fracture to brittleness with the negative shift of the polarization potential. When the cathodic polarization potential is negative to -950 mV, the welding joints have obvious characteristics of hydrogen embrittlement. (paper)