Study On One-side Welding With Back Formation Technique Of Robot MAG Welding

According to the recent butt welding of shipbuilding pipes, it needs manual backing welding, filling in and cover welding by robotization, the welding process involved of two series of welding power, it is not only waste time but also manpower; on the other, the deposition efficiency of traditional backing welding of welding rod arc welding and manual CO2 welding is poor, the human factors have large effect on welding, the welding quality is not stable,it's difficult to meet the needs of industry robotization. Thus proposed one-side welding with back formation of robot, backing welding is the key procedures of the entire welding process. The robot backing welding is suit for the simple structure parts, the high precision of workpiece groove machining and assembling, the production scale is producing in mass, welding in a flat direction, but the pipes have big size bias and ellipticity, it needs study the welding technology of pipes with different sizes under different groove gap. In this paper ,study the robot up back welding of flat board firstly, ascertain the favorable tilt angle range for better back formation, then match it on pipe welding, make the right arc starting position and establish the welding parameters of each groove gap.The groove gap range which this paper studied is 0～3mm, the workpiece tilt angle is 10°～60°, under this condations, studied the flat board welding technology, with orthogonal experimental method by changing welding current, arc voltage, welding speed and wave parameters, according to the request of welding techology make the robot backing welding parameters, compared the size of workpiece tilt angle of the best back formation with different gaps, take it as guide for arc starting position of backing welding.Studied the relationship among welding parameters, the effect of each parameters on the back reinforcement. According to the datum analysis get the relations between welding current and groove gap, the blunt side; analyzed the effect of welding current, arc voltage and welding speed varieties on the back reinforcement, then ascertain the direct proportion relation between welding heat import and the back reinforcement, thus it can get the heat import needed under the definite back reinforcement;When other welding parameters is definite, studied effect of groove size on weld back formation; on the basis of constant groove gap and other parameters, change the size of tilt angle, analyze the relations between variety of tilt angle and back reinforcementAccording to experiment studied the groove gap range of 0.5～2.5mm, pipe-pipe backing welding technology on the type ofΦ425×10 pipe, for the flat board, with good back reinforcement of different gaps under the best tilt angle, from the experiment result, when the tilt angle is 40°, that is the best arc start position with different gap at the direction of 1:30, then according to parameters optimization made the pipe back welding parameters with different gaps, such as when the gap is 1.5～2mm,welding current is 110～140A,welding voltage is 20.4～21.1V, and welding speed is 0.08～0.12m/min will get the good face and back formation.Analyzed the stability and limits of robot backing welding, to assimilate the experience for the robot welding in future; Adopted the robot backing welding compared with manual backing welding, the weld formation is beautiful, and the welding quality is stable, simultaneously, improved the labour productivity greatly, it has large societal and economical benefits.