조선용 아연코팅강판의 CO2 레이저 겹치기 용접시 인프로세스 측정신호와 용접결함과의 관련성

The Relationship between In-process Signals and Weld Defect in CO2 Laser Lap Welding of Zn-coated Steel for Shipbuilding

The in-process monitoring of CO2 welding of Zn-coated steel plates has been studied and compared with that of conventional thin plates. Relationships between weld defects and plasma emission signals were evaluated in laser lap joint of thick Zn-coated steel. According to the study, weld defects were found to increase with Zn content. As a result, measured plasma emission signals also decreased. In case of plate with 15μm-thick Zn-coated layer, defects caused by evaporation of Zn could, therfore, controled by gap of 0.1mm, resulting in a stable emission signals. However, the amplitude of signals fluctuated very widely. Variation of amplitude sould be limited in 3-8V by FFT smoothing.