Effect of weld metal strength and welding conditions - on reaction forces and stress distribution of restrained components

摘要

During the past decades, weldability studies have predominantly been concentrated on the material and the welding process. In order to achieve a closer insight into the structural effects, component weldability tests were performed by on-line monitoring of the reaction forces and moments. In particular, the effects of different values of the base material and weld metal strength on the reaction force and stress build up transverse to the welding direction were studied at a specific structural restraint. As a most relevant result for practical welding, it was demonstrated that the final reaction force and also the reaction stress level in the multi layer but welds decreases with overmatch of the weld metal. Tests were made on multilayer submerged-arc welds made of fine-grained structural steels S460ML and S890NL. Reaction forces and moments built up during welding and subsequent cooling were measured in a specifically designed large scale testing facility. Residual stresses were measured by the hole drilling technique after cooling of the specimens in the restrained as well as in the relieved condition.