Synchronous Magnetic Field On Short Circuit Arc Drop Transfer Mechanism Research

CO₂gas shielded arc welding is a low-cost, high-efficiency welding method, so it iswidely used in the welding of mild steel and low alloy steel and other ferrous materials.However, CO₂gas shielded arc welding has the shortcomings of big spatter and badformation, the two major drawbacks become the problems of CO₂gas welding in industrialapplications. My topic by joining synchronous magnetic field method can effectively solvethis problem, deal with the fundamental contradiction of liquid bridge contraction requireslarge current and reduce spatter needs small current, in addition distinguished fromunordered applied, it has important value of researching to improve weld formation.This article describes the development of joining synchronous magnetic fieldequipment and CO₂gas shielded arc welding short-circuit test. Independently developed adevice for synchronous magnetic field is applied to short-circuit the transition, includingmagnetic field generating device, the synchronization device of detecting the short circuittransfer information as well as the design of the head structure, the equipment has theadvantages of small size, easy operation and controlling well. As experiments, introducevertical synchronization magnetic field to the CO₂welding short-circuit transition process,Q235low carbon steel as the research object, shooting additional magnetic field drop andarc form, contrast the magnetic field on the influence of the weld formability and spatterrate changes after additional magnetic field etc, study the impact of the transitionmechanism of magnetic field on the short-circuit. The test results show that the dropletafter the external magnetic field by the magnetic field change from spherical to ellipsoidal;The morphological changes of the arc from tapered into a bell-shaped, and the arc length isshortened with the increase of the excitation current, the arc rotates under the biasing forceof the magnetic field, the weld pool has been agitated; Applied magnetic field on a markedimprovement in the weld forming, welding current is150A, the excitation current is5A,the frequency is100Hz, this moment has the biggest rate of Weld width increase,21.7%;The spatter rate measurements show that spatter rate in the external magnetic field is significantly reduced and there is a optimization of the magnetic domain in a certainwelding under standard, welding current is150A, the excitation current is3.5A, thefrequency is80Hz, there has the lowest spatter rate2.66%.