Electric welding is currently the most widely used welding method. It includes: hand arc welding, submerged arc welding, tungsten gas shielded arc welding, plasma arc welding, gas metal arc welding and so on. Most arc welding is based on the arc of combustion between the electrode and the workpiece. When forming the joint, the filler metal may or may not be used. When the electrode used is a wire that is melted during the welding process, it is called a molten arc arc welding, such as hand arc welding, submerged arc welding, gas shielded arc welding, tubular wire arc welding, etc.; the electrode used is not melted during the welding process. When a carbon rod or a tungsten rod is used, it is called non-melting arc welding, such as tungsten argon arc welding, plasma arc welding, and the like. (1) Hand arc welding Hand arc welding is one of the earliest and most widely used welding methods in various arc welding methods. It is an electrode and a filler metal with an externally coated electrode. The arc is burned between the end of the electrode and the surface of the workpiece being welded. On the one hand, the coating can generate gas to protect the arc under the action of arc heat, and on the other hand, it can produce slag covering the surface of the molten pool to prevent the interaction of the molten metal with the surrounding gas. The more important role of slag is to produce a physicochemical reaction with molten metal or to add alloying elements to improve weld metal properties. The hand arc welding equipment is simple, light and flexible. It can be applied to the welding of short seams in maintenance and assembly, especially for welding in hard-to-reach areas. Hand arc welding with the corresponding electrode can be applied to most industrial carbon steel, stainless steel, cast iron, copper, aluminum, nickel and their alloys. (2) Submerged arc welding Submerged arc welding is a wire that is continuously fed as an electrode and a filler metal. During welding, a layer of granular flux is coated on the upper surface of the weld zone, and the arc is burned under the flux layer to melt the end of the wire and the local base material to form a weld bead. Under the action of arc heat, the upper part of the flux melts the slag and undergoes a metallurgical reaction with the liquid metal. The slag floats on the surface of the molten metal pool, which can protect the weld metal, prevent air pollution, and produce physical and chemical reactions with the molten metal to improve the weld metal and performance. On the other hand, the weld metal can be made. Slowly licking. Submerged arc welding can use a larger welding current. Compared with hand arc welding, its biggest advantage is the good weld quality and high welding speed. Therefore, it is particularly suitable for welding straight seams of large workpieces. And most use mechanized welding. Submerged arc welding has been widely used in the welding of carbon steel, low alloy structural steel and stainless steel. Since slag can reduce the joint cooling rate, some high-strength structural steels, high-carbon steels, etc. can also be submerged arc welded. (3) Tungsten gas shielded arc welding This is a non-melting gas shielded arc welding that utilizes an arc between the tungsten electrode and the workpiece to melt the metal to form a weld. During the welding process, the tungsten electrode does not melt and acts only as an electrode. At the same time, argon or helium is fed from the nozzle of the torch for protection. Additional metals can be added as needed. Internationally known as TIG welding. Tungsten gas shielded arc welding is an excellent method for joining sheet metal and bottoming because it provides excellent control of heat input. This method can be used for almost all metal connections, especially for welding aluminum, magnesium, metals that form refractory oxides, and reactive metals such as titanium and zirconium. This welding method has a high weld quality, but its welding speed is slower than other arc welding. (4) Plasma arc welding Plasma arc welding is also an infusible pole arc welding. It uses a compression arc between the electrode and the workpiece (called a forward transfer arc) to achieve welding. The electrode used is usually a tungsten electrode. The plasma gas that produces the plasma arc can be argon, nitrogen, helium or a mixture of both. It is also protected by an inert gas through the nozzle. Filler metal may be added during welding or without filler metal. In plasma arc welding, the arc penetration ability is strong due to the straightening of the arc and the high energy density. The small hole effect produced by plasma arc welding can be used for the non-grooving of most metals in a certain thickness range, and the penetration and weld uniformity can be ensured. Therefore, plasma arc welding has high productivity and good weld quality. However, plasma arc welding equipment (including nozzles) is relatively complicated and requires high control of welding process parameters. Most metals that can be welded by tungsten gas shielded arc welding can be plasma arc welded. In contrast, for the welding of extremely thin metals of 1 mm or less, plasma arc welding can be easily performed. (5) MIG gas arc welding This welding method uses an arc that is continuously burned between the welding wire and the workpiece as a heat source, and the gas ejected from the torch nozzle protects the arc for welding. The protective gas used for the gas arc shielded arc welding is argon gas, helium gas, CO 2 gas or a mixture of these gases. When argon or helium is used as shielding gas, it is called molten inert gas shielding arc welding (referred to as MIG welding in the world); when inert gas and oxidizing gas (O2, CO2) are used as shielding gas, or When the CO2 gas or the CO2 + O2 mixture gas is a shielding gas, or when the CO2 gas or the CO2 + O2 mixture gas is used as a shielding gas, it is collectively referred to as a molten-polar active gas-protected arc welding (referred to as MAG welding in the international market). The main advantage of the gas-shielded arc-shielded arc welding is that it can be easily welded at various positions, and also has the advantages of high welding speed and high deposition rate. Molten active gas shielded arc welding can be applied to most major metals, including carbon steel and alloy steel. MIG welding is suitable for stainless steel, aluminum, magnesium, copper, titanium, zirconium and nickel alloys. Arc spot welding can also be performed using this welding method. (6) Tubular wire arc welding Tubular wire arc welding is also performed by using an arc that burns between a continuously fed wire and a workpiece as a heat source, and can be considered as a type of gas metal arc welding. The wire used is a tubular wire containing various components of flux. When welding, a protective gas is added, mainly CO. The flux is decomposed or melted by heat, and plays a role in protecting the pool, infiltrating the alloy and stabilizing the arc. In addition to the advantages of the above-described gas-shielded arc-shielded arc welding, the tubular wire arc welding has advantages in metallurgy due to the action of the flux in the pipe. Tubular wire arc welding can be applied to the welding of most ferrous metal joints. Tubular wire arc welding has been widely used in some advanced industrial countries. Solar Light,Led Garden Light,Led Solar Light,Outdoor Garden Lights Jiamei Energy(hongkong) Limited , https://www.jiameilight.com
Type of welding