Abstract: Effect of post-weld heat treatment (PWHT) on microstructure, intergranular corrosion resistance and stress corrosion resistance of the weld joint of S30408/Q345R stainless steel clad plates was studied. The results show that after the PWHT (580 ℃ for 2 h), the alloying element diffusion occurs near the fusion line between transition layer weld and base layer weld of the weld joint, and the range of decarburization layer decreases. After the PWHT, the intergranular corrosion resistance of the weld joint decreases, and the corrosion crack is located near the weld fusion line. The PWHT has little influence on the stress corrosion resistance of weld joints. No secondary fracture is found at the tensile fracture of the weld joint, and the stress-corrosion cracking sensitivity ratio of the S30408 stainless steel clad layer is low, showing the stress corrosion sensitivity is small.

Key words: post-weld heat treatment, stainless steel clad plate, microstructure, intergranular corrosion, stress corrosion