Optimization of Welding Materials and Conditions for High Speed Submerged Arc Welding of Spiral Pipe

Spiral pipe mill in which submerged arc welding is made immediately after pipe forming limits the productivity by the welding speed. The higher welding speed is restrained by occurrence of inner bead defects such as undercutting and concave shape.The high speed spiral welding techniques including development of new flux and determination of proper welding parameters were established by laboratory simulation tests.By applying these techniques to actual spiral pipe mill, it became possible to obtain 4m/min in welding speed.