Study on the arc pressure of TIG welding under the condition of Ar-Ar and Ar-He supply alternately

Abstract

Abstract In the paper, a self-made water-cooled copper plate device was used to measure and analyze the welding arc pressure of alternate argon supply under different frequencies of 1 Hz, 2 Hz, 4 Hz and argon and helium supply alternately under different frequencies of 1 Hz, 4 Hz. The experimental results indicated that in the process of alternate argon supply, the maximum arc pressure produced significant fluctuation in a diameter of 1 mm range of the arc center, resulting in the molten pool surface exposed to the acting of pulsating pressure. Besides, the arc center pressure changed with the convert of argon-arc and helium-arc during argon gas and helium gas supply alternately. And the weld seam subjected the pulsating pressure from the process of argon-arc and helium-arc stroked alternately, leading to the change of welding surface formation. Furthermore, under the condition of alternating gas supply, the weld surface presented the typical distribution pattern of fish scale.