Formation of welding burrs on deep-sea oil pipe based on electromagnetic heating

Abstract

High-frequency resistance welding relates to electromagnetic-thermal coupling, causing the formation of welding burrs under the action of an extrusion force, and the morphology of the welding burrs is influenced by the welding temperature field. The welding burr model of solid-liquid two-phase deformation in a high-frequency electromagnetic heating process established in this paper discloses how the temperature and velocity fields vary in the welded zone under the action of an extrusion force and the mechanism of action of temperature on burr morphology. This is the core basis for establishing artificial intelligence (AI) for burr morphology based on machine vision. With the increase in extruded length, the high-temperature zone gathers toward the internal and external welding burrs. At the weld seam, the resultant velocity is relatively high on both internal and external surfaces and is lowest in the middle. On this basis, the influences of different process parameters on burr morphology and the welding quality are analyzed. As the welding temperature rises, the ratio of weld reinforcement to burr width decreases gradually. The correlations between the process parameters for electromagnetic heating and burr morphology are disclosed quantitatively by expounding the extrusion welding process for welded pipes under electromagnetic heating for the purpose of exploring the welding quality characterized by burr morphology under different process parameters and to promote the development of AI for electromagnetic extrusion processes.