Dominant parameter of weld angular distortion in structural materials based on theory of inherent strain (Development of accuracy management system for high quality construction in welded structures on the basis of advanced theory of inherent strain)

Abstract

In this paper, a dominant parameter of weld angular distortion is discussed based on the identically-distributed inherent strain within mechanical melting zone, which is customized for quantifying and coordinately managing the weld angular distortion generated in structural materials, such as structural steel, austenitic stainless steel and aluminum alloy. The parameters dominating the dimensions of mechanical melting zone, which corresponds approximately to the generation area of inherent strain controlling the weld angular distortion, and the value of identically-distributed inherent strain within mechanical melting zone were derived from thermo-mechanical process in welding on the basis of material properties, welding heat input conditions and dimensions of weld specimens. TIG bead-on-plate welding of structural materials was performed under the various welding conditions to investigate systematically the effect on weld angular distortion. All of experimentally-obtained weld angular distortions were arranged by the conventional thermal elastic-plastic parameter and the newly-developed parameter of mechanical melting zone, respectively. As the results, the weld angular distortions can be arranged more coordinately by the developed parameter. It was thus concluded that the developed parameter became useful for coordinately managing the weld angular distortion generated in structural materials. The expected benefit from the developed parameter is assembling a welding condition-dependent database of inherent strain applied for simplified weld distortion analysis of large structures.

Keywords

• angular distortion
• inherent strain
• dominant parameter
• material properties
• welding heat input conditions
• dimensions of weld specimen