Radioactive Isotope S³⁵ applied in Weld Research (Report 2)

On the diffusion of sulphur from the parent-plate into the weld metals

Abstract

By using the mother plates containing Radioactive Isotope S the-authors investigated the phenomenon of diffusion of sulphur from the mother plates to the weld-metals under multi-pass electric arc-welding.
As the result of this experiment it was revealed that ;
1) The influence of sulphur of the parent plate extends clearly to the fifth pass of weld metals in the multi-pass welding.
2) Although the absolute mass of sulphur absorbed by slag from the weld metal increases with sulphur content of parent-metal, the Desulphurization Ratio" decreases according to the increases of sulphur content of parent plates or weld metal on which the next welding pass may be run in multi-pass welding.
3) It was found by counting test that there is a slightly more sulphur in the heat-affected zone under the weld metal than the other parts of parent-plate, and, it is guessed that this phenomenon will be caused by the thermal diffusion of sulphur which existed, at first, in the outside of the heataffected zone.