Investigation of swelling during seal‐welding of tubing and technology for its prevention: Study of welding of zirconium alloy tubing (1st report)

Summary Swelling is liable to occur during welding of tubing which has some internal gas volume. The present study aims to clarify this phenomenon experimentally and to develop a technology for its prevention during seal‐welding of Zircaloy‐2 tubing. Swelling occurs inside the weld metal when the pressure differential inside and outside reaches a critical value as the internal pressure increases. Swelling then develops towards the outside as the pressure increases.