A Study on Bead Height Control of GMAW by Short Circuit Time Ratio

J. Ocean Eng. Technol. 2002;16(2):53-59.

단락시간비를 이용한 GMAW의 비드 높이 제어에 관한 연구

감병오,조상명,김상봉

부경대학교 대학원 학연기계공학,부경부경대학교 재료공학부,부경부경대학교 기계공학부

Keywords: GMAW, Gas Metal Arc Welding, Short Circuit Time Ratio, Short Circuit Frequency, Backing Stripe, Burn Through, Moving Average

핵심용어: 가스금속 아크용접, 단락시간비, 단락주파수, 이면받침, 용락, 이동평균, 표준편차

Abstract

This paper shows the experimental results controlling the height of surface and back bead in GMAW by analyzing the unexpected gaps between base metals produced in welding and by controlling welding velocity due to the variation of the gap between base metals in thin-plate welding. The back bead behavior and burn-through in I-type butt joint $CO_2$ welding of thin mild steel are analyzed in the views of short circuit time ratio and short circuit frequency. It is shown through experimental consideration that the short circuit time ratio method is more reasonable than the short circuit frequency method in analyzing the formulation of back bead under changing the gap between base metals. Based on the these results, welding manipulator is designed so as to satisfy the bead height control in real time by measuring the short circuit time ratio. To show the effectiveness of the developed bead formulation control system, the experiment is implemented under two welding conditions such as increasing gap from 0mm to 0.8mm and gradually increasing gap from 0mm to 1.2mm. The experimental results show that the bead formulation can be controlled uniformly in spite of the variation of the gap between base metals.