1, TIG welding is generally a hand-held welding gun, the other hand welding wire, suitable for small-scale operation and repair of manual welding.
2, MIG and MAG, welding wire through the automatic wire feeding mechanism from the welding gun, suitable for automatic welding, of course, you can also use manual.
3, the difference between MIG and MAG is mainly in the protective gas. The equipment is similar, but the former is generally protected by argon gas and is suitable for welding non-ferrous metals; The latter is generally doped with carbon dioxide active gas in argon, which is suitable for welding high-strength steel and high-alloy steel.
4, TIG, MIG are inert gas shielded welding, commonly known as argon arc welding. The inert gas can be argon or helium, but argon is cheap, so it is commonly used, so the inert gas arc welding is generally called argon arc welding.
Comparison of MIG welding and TIG welding
Comparison of MIG and TIG welding MIG welding (metal inert gas welding) uses a melting electrode.
The arc welding method, which uses external gas as arc medium and protects metal droplet, welding pool and high temperature metal in welding zone, is called MIG arc welding.
Inert gas (Ar or He) arc welding with solid core wire is called MIG welding, referred to as MIG welding.
MIG welding is the same as TIG welding except that the tungsten electrode in the torch is replaced by a metal wire. Therefore, the welding wire is melted by the arc and fed into the welding zone. The electric drive roller sends the wire into the torch from the spool according to the welding requirements, and the heat source is also DC arc.
But the polarity is the opposite of that used in TIG welding. The protective gas used is also different, and 1% oxygen is added to argon to improve the stability of the arc.
Like TIG welding, it can weld almost all metals, especially for welding aluminum and aluminum alloys, copper and copper alloys and stainless steel and other materials. There is almost no oxidation burning loss in the welding process, only a small amount of evaporation loss, and the metallurgical process is relatively simple.
TIG Welding (Tungsten Inert Gas Welding), also known as non-molten inert gas tungsten welding. Whether it is manual welding or automatic welding 0.5 ~ 4.0mm thick stainless steel, TIG welding is the most commonly used welding method.
The method of TIG welding with filler wire is commonly used in the bottom welding of pressure vessels, because the better air tightness of TIG welding can reduce the porosity of the weld during the welding of the pressure capacitor.
The heat source of TIG welding is DC arc, the working voltage is 10 ~ 95 volts, but the current can reach 600 A.
The correct connection method of the welding machine is to connect the workpiece to the positive electrode of the power supply, and the tungsten electrode in the welding torch is used as the negative electrode.
The inert gas is usually argon, which is fed through the welding torch to form a shield around the arc and on the welding pool.
To increase the heat input, 5% hydrogen is generally added to argon. However, when welding ferritic stainless steel, it cannot be
Gas consumption is about 3 to 8 liters per minute.
During the welding process, in addition to blowing inert gas from the torch, it is best to also blow gas from under the weld to protect the back of the weld.
If necessary, the weld pool can be filled with welding wire of the same composition as the austenitic material to be welded. Type 316 filler is usually used when welding ferritic stainless steel.
TIG welding is widely used in welding due to the protection of argon, which can isolate the harmful effect of air on molten metal.
Easily oxidized non-ferrous aluminum, magnesium and its alloys, stainless steel, superalloy, titanium and titanium alloys, as well as refractory active metals (such as molybdenum, niobium, zirconium, etc.), and general carbon steel, low alloy steel and other ordinary materials, in addition to the welding quality requirements of high occasions, generally do not use TIG welding.
