Leakage Reason Analysis in Cylinder of Tower D210

The leakage reason in cylinder of the tower D210 was analyzed by chemical composition analysis,metallographic examination and fracture analysis. The analysis result showed that the leakage was caused by stress corrosion cracking which resulted from existing chloride ion. Under the certain temperature,stress corrosion crack produced at the combined effect conditions of sensitive materials,stress corrosion circumstance and tensile stress. The crack,which initiating in fillet weld on outer cylinder,extended to the wall and eventually penetrated the tube wall. Then towers cylinder leaked on the fillet weld.