抄録
The effects of the weld heat input and the pipe wall thickness on the intergranular stress corrosion cracking (IGSCC) behavior of 304 stainless steel pipe welds were studied by means of the CBB test in simulated boiling water reactor environment. Results are summarized as follows. (1) As the weld heat input becomes higher, the IGSCC susceptible region in the weld heat affected zone (HAZ) becomes more distant from the weld fusion line. However, the IGSCC susceptibility itself is not uniformly related to the weld heat input in such a manner that the IGSCC susceptibility at a weld heat input of 1, 000J/mm is rather higher than that at 2, 000J/mm. (2) As the pipe size (pipe wall thickness) becomes larger, the IGSCC susceptible region in HAZ becomes closer to the weld fusion line, and also the IGSCC susceptibility itself becomes higher. (3) These behavior are described from the viewpoints of the chromium depletion theory based on analytical results of the weld heat cycle.
