RESISTANCE WELDING CONTROL METHOD FOR PLATED STEEL PLATE

PROBLEM TO BE SOLVED: To obtain good welding quality regardless of the progress state of electrode abrasion in resistance welding of a plated steel plate.SOLUTION: In a resistance welding control method to perform welding while performing constant power control so that an instantaneous power value equals an electric power set value Pr, it is assumed that the electric power set value Pr is a value varying along with a welding elapsed time t according to a previously decided electric power target pattern. The electric power target pattern takes an initial value Ps at a welding start time, gradually ascends to take a first peak value Pp1 at a first welding elapsed time T1, and then, gradually descends to take zero at a second welding elapsed time T2. During a cooling time Tc from the second welding elapsed time T2 to a third welding elapsed time T3, the pattern continuously takes zero, and then gradually ascends to take a second peak value Pp2 at a welding end time Te. A plated layer is removed with the first peak value Pp1, and excessive heat input is restrained by the cooling time Tc, and consequently good welding quality is obtained.