Differences between TIG and MIG welding

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TIG welding (tungsten inert gas welding) is a welding method that uses pure Ar as the shielding gas and a tungsten electrode. TIG welding wire is supplied in straight strips of a certain length (usually 1m). Gas shielded arc welding using pure tungsten or activated tungsten (thorium-tungsten, cerium-tungsten, zirconium-tungsten, lanthanum-tungsten) as non-melting electrodes, in which the arc between the tungsten electrode and the workpiece is used to melt the metal and form a weld. During welding, the tungsten electrode does not melt; it merely serves as an electrode. At the same time, argon or helium is supplied through the nozzle of the welding torch for protection. Additional metals can also be added as needed. It is commonly known internationally as TIG welding. Advantages: The main advantage of the TIG welding method is its ability to weld a wide range of materials, including workpieces with a thickness of 0.6 mm or more. The materials involved include alloy steel, aluminum, magnesium, copper and their alloys, gray cast iron, various bronzes, nickel, silver, titanium, and lead. The main application area is welding thin and medium-thickness workpieces, and it is used as a root pass on thicker sections. MIG welding, also known as metal inert gas welding, is a type of arc welding that uses inert gases such as Ar as the primary shielding gas; it involves using pure Ar or Ar mixed with small amounts of active gases such as less than 2% oxygen or less than 5% carbon dioxide for this purpose. MIG welding wire is supplied in coils or spools in a layered form. This welding method uses an arc that is generated between a continuously fed weld wire and the workpiece as the heat source, with gases emitted from the welding torch tip used to protect the arc during welding. Advantages: It facilitates welding in various positions, and it also features a fast welding speed and a high deposition rate. Melted electrode gas shielded arc welding can be used for welding most major metals, including carbon steel and alloy steel. GMAW is suitable for stainless steel, aluminum, magnesium, copper, titanium, zirconium, and nickel alloys. Arc spot welding can also be performed using this welding method. Precautions for TIG welding A: Required flow rate of the shielding gas – 7–12 L/min when the welding current is between 100–200 A ； : A rate of 12–15 L/min is appropriate when the welding current is between 200–300 A. B. The protrusion length of the tungsten electrode relative to the nozzle should be as short as possible; the arc length should generally be maintained between 1-4 mm (and 2-4 mm when welding carbon steel) ； 1-3 mm for welding low-alloy steel and stainless steel) ； C. Wind protection measures should be adopted when the wind speed is greater than 1.0 m/s ； Pay attention to ventilation to avoid harm to the operator ； D. During welding, thoroughly remove impurities such as oil, rust, and moisture from the welding area. E. It is recommended to use a DC power supply with a steep droop characteristic, with the tungsten electrode as the positive pole. F, when welding low-alloy steels with 1.25% Cr or more, the back side also needs to be protected. For MIG welding A, an argon gas flow rate of 20–25 L/min is appropriate ； B. The arc length is generally kept at around 4-6 mm ； C. Wind has a particularly adverse effect on welding; windproof measures should be taken when the wind speed exceeds 0.5 m/s ； Pay attention to ventilation to avoid harm to the operator ； D. By using pulsed arc current, a stable spray arc can be achieved, which is particularly suitable for welding stainless steel, thin sheets, in vertical position, and for surfacing welding ； E. Please use an Ar+2% O2 gas mixture for welding ultra-low carbon stainless steel; do not use a mixture of Ar and CO2 for welding such steel ； F. During welding, strictly remove impurities such as oil, rust, and moisture from the welding area