Passive probe-coil magnetic field test of stress-strain state for welded joints

Abstract

The most common destruction places of welded metal structures are the welded seam and the heat-affected zone. These zones are stress concentrators, even if there are no defects. Equally important is the goal of preventing corrosion damage while improving the reliability and safety of welded metal structures. The most promising is the passive probe-coil magnetic field test method, which allows a complete examination of the alleged places of corrosion damage without surface preparation. The study is dedicated to identifying the most dangerous zones and places of the welded joint, and which of them must be controlled in the first place. The aim of the paper is to develop a methodology for assessing the stress-strain state of welded joints, taking into account the structural and mechanical heterogeneity of the metal. Correlations between the values of magnetic parameter Hp and the acting stresses σ in the controlled zones under uniaxial elastic tension of the samples are determined. A metallographic analysis of welded joints of structural steels was carried out. It was revealed that the most dangerous area of the welded joint in metal structure is the fusion zone of the weld and the base metal with the overheating area.