Visualization and Analysis of Groove Residual Magnetism for Narrow Gap Arc Welding

Abstract

Residual magnetism obviously exists in welding groove of high strength steel and thus influences narrow gap arc welding quality. The present work investigates the characteristics of residual magnetism for U-shape welding groove, and reveals its formation mechanism by physically modeling the residual magnetism. An experimental data based visualization approach is then proposed to characterize dominant distributions of residual magnetism. It is shown that residual magnetism is much stronger in groove width and at groove bottom respectively than in groove length and at groove top, as well as of bar magnet features for each groove sidewall. Two-dimensional visualization of residual magnetism vector is realized by plane and curved surface cloud maps of equivalent color bars, while three-dimensional visualization is expressed by assembling six outermost plane cloud maps of residual magnetism in groove measuring space. The built models and digital visualizations well contribute to understand the phenomena of residual magnetism.

Three-dimensional distribution of B_x. (a) Groove U₁; (b) Groove U₂.