SUBMERGED ARC PRESS WELDING METHOD FOR STEEL BARS HAVING LARGE DIAMETER

摘要

PROBLEM TO BE SOLVED: To improve weld quality by preventing the fluctuation of a welding voltage and a defective arc start when starting welding, which are caused by the fluctuation of a heat input during the welding and a short circuit between molten metal at the tip of a steel bar and a molten pool on a steel plate in a welding method for the steel bar having a large diameter in a submerged arc press welding method.;SOLUTION: By calculating the heat input based on a welding current and the welding voltage during the welding, and making a welding heat input constant by finishing the welding when the heat input has reached a prescribed welding heat input controlling the heights of the steel bars so that the welding voltage during the welding becomes a prescribed value and controlling the heights of the steel bars so that the welding voltage becomes a prescribed value even when fails to start the welding, an arc is made to start again.;COPYRIGHT: (C)2001,JPO