Study On The Processing And Properties Of Twin Deposition Basic Electrode Arc Welding

Twin deposition basic electrode arc welding is a newly developed welding method which uses the heat carried by the droplets and generated by the arc to melt the base metal and form the weld. During this procedure, workpiece is separated from the power supply while the arc formed at the end of the paralleled twin deposition electrodes. This welding method is characterized by easy adjusting of heat input, low dilution, high depositing coefficient and electric efficiency, low distortion and stress. Consequently, it is promising welding method with high quality, energy saving. In this paper, the processing and properties of twin deposition basic electrode arc welding was investigated.Results show that arc voltage is determined mainly by the space between twin electrodes while the distance between workpiece and electrode has little effect on it. For electrode with diameter of 4mm, fine performance of welding can be obtained under following processing parameters: space between twin electrodes is 0.65mm-0.8mm; welding current is 160A-200A; distance between the end of electrode and workpiece is 4mm- 9mm.For twin deposition basic electrode with a definite space between twin electrodes, the welding voltage increases linearly with the increase of welding current, and the width of bead, penetration and dilution all increase. However, the reinforcement changes slightly and the penetration ratio decreases with increase of welding current.In the microstructure of the welding bead of the twin deposition basic electrode the welding bead contains dendrite made up of ferrite and little pearlite. The fusion area and over-heated zone composed of coarse ferrite and pearlite, and widmanstaten structure even appears. Fine crystalline area is composed of fine ferrite and pearlite. With the increase of welding current, grain of weld , melting zone and over-heated...