Finding the existence of a tendency for stress corrosion
The level of residual stress in the weld seam
The presence of residual stress will strengthen the tensile stress environment, stress corrosion cracks generally appear in welds with high welding residual stress. Post-weld heat treatment can significantly reduce the tendency to stress corrosion. The residual stress in the weld can be measured by the residual stress test, and the heat treatment status of the weld can also be judged by the weld hardness test. To detect stress corrosion cracks, an effective way is to carry out the fluorescent magnetic particle inspection of the inner surface of the tank, which has been proved to have a high crack detection rate, and can also be used in conjunction with the metallographic examination to determine the nature of cracks and determine whether there is stress corrosion microcracks.
