Evaluation of Flashing in the Short Period before Upsetting for Monitoring of Weld Quality and Process Control

Welding Phenomena and Process Control in the Flash Welding of Steel Sheets (report 4)

Abstract

Influence of flashing on weld quality was investigated by analyzing the welding current in the short period before upsetting. Regression analysis proved that the integration of the flash current with an weight function could be related with the initial upset displacement and the weld interface quality. The time constant of the exponential weight function was discussed in connection with the period, flashing during which was effective to improve the weld interfece quality, and also in connection with the temperature neccessary to attain satisfactory interface quality. Process control system was proposed based upon the flash current evaluation to improve interface quality of joints.