Comparison of submerged arc welding process modification influence on thermal strain by in-situ neutron diffraction

In this paper the application of neutron diffraction for measuring the thermal strain field in the vicinity of the weld pool during submerged arc welding is described. The aim of the research was to determine the influence of a welding process modification on the thermal strain within a sample rod. The welding experiment was carried out on the instrument STRESS-SPEC at the MLZ FRMII facility in Garching, Germany. Submerged arc welding equipment with additional cold wire feeding was adapted to the diffractometer and thereon single layer bead-on-plate welds were carried out. Sample rods made of the nickel base alloy 625 were used. The measured strain values are presented and discussed with respect to the resulting weld bead geometry and the thermal profile within the sample. (author)