Research on joint property of twin wire submerged arc welding

The welding of 16Mn steel plate is conducted using twin wire submerged arc welding technology.The weldments are prepared under the condition of the different welding speeds.For the welded joints obtained by above-mentioned welding processes,the tensile tests of the welded joints are performed,the hardness of the joint metal is measured,and the welded joint microstructure is observed.Moreover,the metal deposition rate is calculated based on the basis of the experimental data.The results show that the excellent welding bead shape is easily obtained by twin wire submerged arc welding process.The metal deposition rate is inversely proportional to the welding travel speed.The decrease of welding speed results in the corresponding increase of the welding heat input,the longer existing time of welding pool at elevated temperature causes to the relatively coarse grain microstructure of both HAZ and weld metal.The tensile and the yield strength of the joints obtained by above-mentioned welding processes are distinctly different.The microhardness of weld metal is increased and the toughness of welded joints is decreased as the welding travel speed is increased.