2 History of Arc Welding Arc welding dates back to the late 1800’s First developed following the invention of AC electricityPioneered when a man was welding with a bare metal rod on iron, the sparks from the welding caught a stack of newspapers on fire near him and while welding, he noticed that his welds started looking a lot better. The reason for this was the smoke took the oxygen out of his welding environment and decreased porosity.
3 What is Arc Welding?The fusing of two or more pieces of metal together by using the heat produced from an electric arc welding machine.
4 Basics of Arc WeldingThe arc is struck between the electrode and the metal. It then heats the metal to a melting point. The electrode is then removed, breaking the arc between the electrode and the metal. This allows the molten metal to “freeze” or solidify.
5 How an arc is formed?The arc is like a flame of intense heat that is generated as the electrical current passes through a highly resistant air gap.
6 Welding Processes SMAW (Shielded Metal Arc Welding) GMAW (Gas Metal Arc Welding)GTAW (Gas Tungsten Arc Welding)Oxygen/ Fuel Welding
7 SMAW Also referred to as “Stick Welding” Used for everything from pipeline welding, farm repair and complex fabrication.Uses a “stick” shaped electrode.Can weld: steel, cast iron, stainless steel, etc.Can also hardface with correct electrode.
11 GMAW Also referred to as “MIG” welding Uses a shield gas and a continuous wire electrodeUsed for all types of fabricationGreat for thin metals up to ¼”Excellent speed of depositionUsed for metals such as: steel, aluminum and stainless steel.
15 MIG Welding Benefits All position capability Higher deposition rates than SMAW Less operator skill required Long welds can be made without starts and stops Minimal post weld cleaning is required
16 GTAW Also referred to as “TIG” Welding Uses a shield gas, a non-consumable tungsten electrode and a hand fed filler rodExcellent for welding thin metals, pipeline welding and exotic metalsHighly skilled labor needed for this process
21 GTAW Welding Benefits Welds can be made with or without filler metal Superior quality welds Welds can be made with or without filler metal Precise control of welding variables (heat) Free of spatter Low distortion
22 Oxygen/ Fuel WeldingUtilizes oxygen and a fuel gas to heat metal until it is in a molten state and fuse multiple pieces of metal together. Can be used with or without a filler rod.Great for brazing dissimilar metals together.Older technology that can be replaced by GTAW