Melting Characteristics of Some Steel and Aluminum Alloy Wires in GMA Welding(Welding Physics, Process & Instrument)

概要

論文の詳細を見る
Wire melting characteristics of steel wire and aluminum alloy wire are examined in electrode positive polarity. In steel wires such as mild steel and stainless steel wire, the contribution of ohmic heating to melting rate of wire electrode takes about 50% in usual welding condition. But, in Al-alloy wire the dominant part of heat input for wire melting comes from anode heat input from arc and ohmic heating has little effect. Shielding gas and arc length have little effect on melting of steel wire. For aluminum alloy wire, main mechanism of heat input is anode heat input. But, remarkable increase in melting rate in short arc length 'intrinsic self-regulating effect of arc length' cannot be attributable to the increase in anode heat input from arc. It must be related to the decrease in heat content of droplet. The decrease in heat content of droplet in rather short arc length in Al-alloy wire welding is associated with climbing up of arc roots in wire electrode. The effect is more intense in Al-5183 wire than in Al-4043 wire. The climbing up of arc roots may increase in effectiveness of uniform heating of wire electrode. This might be caused by intense evaporation at the anode spot due to the existence of volatile element magnesium in the wire.
大阪大学の論文