Analysis of welds on helium-containing restraint test plates

摘要

Over the last several years, Savannah River has had the goal of developing a repair process and the technical understanding necessary to make weld repairs on stainless steel containing helium. This report documents the results of a series of test welds made with varying amounts of mechanical restraint on type 304 stainless steel containing helium from tritium decay. This change in restraint produced different states of stress on the weld area during welding. The test welds were either overlay welds or weave beads. The amount of heat affected zone cracking observed in the welds provided the primary, analysis tool for evaluating the tests. Generally, higher restraint produced greater cracking of the welds. These results, along with previous Savannah River data, indicate that in a practical application of a repair method for helium-containing stainless steel, the effect of part configuration must be considered, as well as the type of weld, to reduce stresses that can cause helium embrittlement cracking.