If you are not interested in optimal settings for a particular job 渔民捕百斤大海龟 合照特朗普站边缘

Home-and-Family What is this AC balance that everyone is talking about that is supposed to be so great for tig welding aluminum? And why should you give a rats ass? Well first lets make sure we know what AC is because, lets face it, we could be talking about Air conditioning, Aircraft, or one half of an Eighties Rock band. AC refers to alternating current. Alternating current means the direction of flow of electric current alternates from negative to positive. The power that you get when you plug a blender into the wall outlet is alternating current. Direct current or DC indicates the current is flowing in only one direction. Batteries supply DC or Direct current. Tig welding machines are available in either strictly DC models or AC/DC models. The DC models are fine for steel but you need AC AND DC to weld steel AND aluminum. Why? Because alternating current allows aluminum oxide to be melted and sort of dissolved without overheating the electrode. The reverse polarity half of alternating current provides what is called a cathodic etch that is very helpful on aluminum. But welding on reverse polarity just overheats the electrode to a point that makes it impractical. Welding on DC electrode negative as is done on steels does not work well because the aluminum oxide remains and makes it impossible to see the puddle. Welding on AC is kind of like baby bears porridge.. just right! Just enough of electrode negative to keep the electrode from getting too hot, and cleaning action or cathodic etching from the reverse half of AC breaks thru the oxide to let you see the puddle. But what does the AC balance do? It lets you adjust the Cleaning vs penetration. Does it really make any difference? In a word, Yes! What if you were tasked with tig welding an aluminum tread plate truck box one day and the next day you needed to tig weld 3 aluminum boat propellers that had been in salt water for a year. One material is clean with a polished finish and the other is heavily oxidized and probably even has subsurface corrosion. One job needs penetration along with a cosmetically pleasing bead, the other job is strictly building up weld metal that will be sanded off. Being able to adjust for more or less cleaning or penetration is kind of like having just the right size hammer for the job instead of making do with one that is too small. How does it work? This is kind of oversimplifying it, but the lower the setting the more reverse polarity and the more cleaning action. The higher the setting, the more electrode negative and the more penetration with a narrower band of cathodic etching marks. Set it and forget it? If you are not interested in optimal settings for a particular job, A setting of 7 with weld almost anything pretty well. About the Author: 相关的主题文章: