The Manufacture Of Twin-wire Submerged Arc Welding EMS Magnetic Power And Design Of The Coil

Submerged arc welding has been widely used in the manufacturing of large-sized workpieces. In order to continuously improve the efficiency of submerged arc welding, double wire submerged arc welding becomes widely used. With the development of the engineering technology, magnetic field is adopted in the processing of submerged arc welding, which successfully improve the crystallization of molten pool, refine the grains and thus improve the welding quality.The influence of magnetic field in the process of submerged arc welding was studied for the first time in the paper. We designed an electromagnetic stirring device which used the dual inverter structure as the main circuit plus the corresponding guard circuit and driving circuit, which adopted SG3525A and SG3526 as the core components. It also included the corresponding feedback circuit and peak detective circuit inside. DC waveforms and the intermittent alternating square-wave are available from the device under the premise of the its continuous stability output, which is completely adequate for the experiments. We also worked out a special magnetic head for the submerged arc welding. The structure of the head is solenoid which has many advantages such as good thermal conduction, simple processing of manufacturing and the magnetic field it produced was able to act on the molten pool effectively. The emulational results of Ansys showed the influence of the magnetic head and the metal base on the distribution of magnetic field. It demonstrated that the magnetic field of the device have an effective influence on the molten pool.Serious measures have been taken to install and adjust the device. Using the developed electromagnetic stirring device, corresponding magnetic field was applied in the submerged arc welding of the D136 steel. The experimental results shows the patterns of influence on the fusion-width, the macrocosm appearance and the metallographic structure of welding beam under different magnetic parameters. The experiments shows that the applied magnetic field has a great influence on the appearance of the welding beam. According to the experiments, the fusion-width decreases from 28 mm to 22 mm under certain magnetic field with the penetration decreases and the weld reinforcement increases in the same time. All of above shows that the electromagnetic stirring is able to improved the weld microstructures by transforming the pearlite to the sorbite under the influence of magnetic field and thus decreases the grain size from 39.8μm to 27.2μm in the welding beam which eventually improves the toughness and strength of the welding beam.