manual arc weldingsubmerged arc

(1)
    Hand a welding arc is the earliest to develop a variety of arc welding method, is still the most widely used method. It is externally coated with the coating of the electrode as an electrode and filler metal, the arc is in the end portion of the electrode and the welder member between the surface combustion. The coatings can be generated in the role of the arc heat on the one hand the gas shielded arc slag covering the bath surface to prevent the interaction of the molten metal with the surrounding gas, on the other hand can produce. A more important role of the slag to produce physical or chemical reaction with the molten metal, or to add alloying elements to improve the performance of the weld metal. Manual arc welding equipment is simple, lightweight, flexible operation. A short seam welding can be applied to the maintenance and assembly can be used for the welding of the parts is difficult to achieve, especially. Hand arc is equipped with the corresponding electrodes applicable to the majority of industrial carbon steel, stainless steel, cast iron, copper, aluminum, nickel and its alloys.
(2)
    Submerged arc welding in a continuous feed wire as electrode and filled metal. Welding, at the upper surface of the weld zone, covered with a layer of granular flux, burning arc in the flux layer of the end portion of the wire and a partial base material melted and formed weld. Under the action of heat in the electric arc, the upper part of the solder melting slag and the metallurgical reaction occurs with the liquid metal. Slag floating on the surface of the molten metal bath, the other hand, can also make the one hand to protect the weld metal, to prevent air pollution, and produce physical and chemical reaction with the molten metal, improvement the extreme and properties of the weld metal; weld metal but slowly Ling. The submerged arc welding can be employed a larger welding current. Compared with manual arc welding, the biggest advantage is good weld quality, high welding speed. Therefore, it is particularly suitable for straight seam welding large workpiece girth. And most mechanized welding. Submerged arc welding has been widely used in the welding of carbon steel, low-alloy structural steel and stainless steel. Joints slag can reduce the cooling rate, some of the high-strength structural steel, high carbon steel submerged arc welding can be used.
(3) tungsten arc gas shielded arc welding
    This is a non-melting pole gas shielded arc welding, using electric arc between the tungsten electrode and the workpiece and the formation of the weld metal melting. Tungsten welding process does not melt, and only plays the role of the electrodes. While feeding argon gas or helium gas from the torch nozzle for protection. But also required the addition of the metal. In the international community, commonly known as TIG welding. Tungsten arc gas shielded arc welding heat input control, so it is connected to the sheet metal and an excellent method for backing weld. This method can almost be used for the connection of all the metal, in particular, suitable for welding aluminum and magnesium which can form a refractory oxide, a metal such as titanium and zirconium active metal. This welding method of weld quality is high, but compared with other electric arc welding, the welding speed is slow.
(4) a plasma arc
     The plasma arc is also a non-Electrode Arc. It is between the electrode and the workpiece compressed arc (called the forward transfer arc) to achieve welding. The electrode is usually used in the tungsten electrode. Generating plasma arc plasma gas is available argon, nitrogen, helium, or wherein both of the gas mixture. Also through a nozzle with an inert gas protection. Can be applied in the welding filler metal, can also be without filler metal. Straight due to its arc, plasma arc welding, and the energy density large, and thus the arc penetrating ability. Such as the the orifice effect generated in the plasma arc welding, for a certain thickness range of most metals can not open the butt, and to ensure penetration and weld uniformity. Therefore, plasma arc welding with high productivity and good quality welds. However, plasma arc welding equipment (including nozzle) is more complex, higher control requirements of the welding parameters. The tungsten electrode gas shielded arc welding can weld most metals, plasma arc welding can be used. Contrast, for 1mm below the welding of thin metal, with a plasma arc can be easier to carry.
(5) MIG arc welding
    This welding method is arc as a heat source, and discharged by a welding torch nozzle gas shielded arc welding using a continuous feed of the wire and workpiece between the combustion. MIG arc welding is usually protective gas: argon, helium, CO2 gas or gas mixture. Argon or helium as a shielding gas, known as metal inert gas shielded arc welding (internationally referred to as MIG welding); protective gas is an inert gas and oxidizing gases (O2, CO2) gas mixture, or CO2 gas or CO2 + O2 mixture for the protection of gas, or for the protection of the CO2 gas or CO2 + O2 mixture gas, collectively referred to as metal active gas shielded arc welding (referred to as MAG welding international). The main advantage of the MIG arc welding is easy for all position welding also has a faster welding, cladding and high. Metal active gas shielded arc welding is applicable to most of the major metals, including carbon steel, alloy steel. Metal inert gas shielded arc welding to apply to stainless steel, aluminum, magnesium, copper, titanium, zirconium, and nickel alloy. This welding method may further arc spot.
(6) The tubular wire arc welding
    Tubular wire arc welding is the use of continuous feeding between the wire and workpiece burning arc welding heat source that is melting a type of gas metal arc welding. The used wire is a tubular wire, contains various components of the flux tube. When soldering, the protective gas is applied, mainly CO. Flux thermal decomposition or melting, plays the the slagging protected dissolved pool, the role of permeability alloy and stable arc. Tubular wire arc welding in addition to the advantage of the MIG arc welding flux tube, so more advantages in metallurgy. Tubular wire arc welding can be applied to most ferrous metal welding various joints. Tubular wire arc welding has been widely used in some of the advanced industrial countries.
       2. Resistance welding
    This resistance heat welding method of energy, including of electroslag welding slag resistance heat energy and of solid resistance heat energy resistance welding. Because of the the electroslag welding more unique characteristics, described later on. Here introduces several solid resistance thermal energy resistance welding, spot welding, seam welding, projection welding and butt. The ERW Usually the workpiece under pressure at a certain electrode and the welding method of the connection by using a current through the resistance heat generated when the workpiece is melted and the contact surface between the two workpieces. Typically use a large current. Order to prevent arcing occurs on the contact surface and the To Forging weld metal, the welding process should always be applied pressure. Conduct this type of resistance welding, the welder surface of the piece good is of paramount importance for obtaining a stable welding quality. Therefore, before welding must be contact between the electrode and the workpiece and the workpiece and the workpiece surface clean-up. Spot welding, seam welding, projection welding Wu is the welding current (single phase) large (a few thousand to tens of thousands of amperes), short on time (a few weeks wave to a few seconds), expensive equipment, complex, high productivity, and therefore suitable for large mass production. Mainly used for welding a thin plate assembly of the thickness of less than 3mm. Various types of steel, aluminum, magnesium, and other non-ferrous metals and their alloys, such as stainless steel can be welded.
       3. High-energy beam welding
    This type of welding methods including: electron beam welding and laser welding.
(1) The electron beam welding
    The electron beam welding is the welding method of the heat generated by the concentration of high-speed electron beam bombardment of the workpiece surface. The electron beam welding, an electron beam generated by the electron gun and accelerate. Commonly used in electron beam welding: high vacuum electron beam welding, low vacuum electron beam welding and non-vacuum electron beam welding. The first two methods are carried out in a vacuum chamber. The welding preparation time (vacuum time) longer, workpiece size limited by the size of the vacuum chamber. Compared to the electron beam welding and arc welding, the main characteristics of the weld penetration and weld width small weld metal of high purity. It can be used in precision welding of thin material, can be used on very thick (most thick 300mm) components welded. All other welding methods for fusion welding of metals and alloys can be used electron beam welding. Mainly used in products that require high quality welding. Can solve the dissimilar metal, easily oxidized metal and refractory metal welding. However, is not suitable for high-volume products.