In order to ensure stable Welding Electrodes arc and weld surface forming the combustion, arc ignition, the electrode should be made in three directions of movement
(1) Electrode been sent to the weld pool
(2) electrode to move forward along the Welding Cable direction
(3) electrode lateral swing
Electrode movement should move forward with an angle of 70-80 degrees angle to the molten metal and slag into the rear, or front of the arc slag flow, slag will cause defects.
Operation of the method
In order to obtain a wide weld, electrodes in the process of feeding and movement, but also to make the necessary swing. Normal operation of the method is as follows:
(1) linear operation of the method
(2) reciprocating type operation of law
(3) operation of law serrated
Principle - with manual arc Welding Electrode for welding methods. The use of electrodes and welding pieces together between the stable burning arc, the welding wire and pieces of melting, resulting in a strong welded joints. Is a gas - slag joint protection.
Main features - flexible operation; welding head assembly to be low demand; weld metal can be wide; welding productivity is low; weld quality dependence (dependent on skills and on-site welder's play).
Applications - widely used in shipbuilding, boilers and pressure vessels, machinery, building structures, maintenance of chemical equipment and other manufacturing industries. For (the industry) a variety of metal materials, various thickness, the welding of structural shapes.
2, submerged arc welding (welding):
Principle - under the arc in the flux layer burning. Between wire and weld parts using arc heat generated by burning, melting wire, flux and base metal (welding pieces) to form the weld. Is a residue protection.
Key Features - welding production rate; weld quality; welding and low cost; good working conditions; difficult welding position in space; high quality weldments assembly; not suitable for welding sheet metal (welding current is less than 100A, the arc stability is bad) and short weld.
Applications - widely used in shipbuilding, boiler, bridge, crane and metallurgical machinery manufacturing industry. Those who remain in the horizontal position can weld or weldment little inclination angle, can be used submerged. Thickness must be greater than 5 mm (anti burn). Welded carbon steel, low alloy structural steel, stainless steel, heat-resistant steel, composite steel and so on.
3, carbon dioxide gas shielded arc welding (automatic or semi-automatic welding):
Principle: use carbon dioxide as a protective gas MIG arc welding methods. Is a gas protection.
Main features - high welding; welding and low cost; welding deformation of small (arc heating concentration); welding of high quality; simple; splash rate is high; difficult to weld with AC power; wind capacity; can not be welded easily oxidized colored gold.
Applications - mainly for welding low carbon steel and low alloy steel. Suitable for a variety of thickness. Widely used in automobile manufacturing, locomotive and vehicle manufacturing, chemical machinery, agricultural machinery, mining machinery and other departments. 4, MIG / MAG welding (inert gas fusion welding):
Principle - the use of inert gas as a protective gas, the use of wire as an electrode arc melting method.
Protective gas is usually argon or helium or their mixture. With inert gas MIG, MAG adding a small amount of inert gas in the reactive gases such as oxygen, carbon dioxide gas.
Key Features - welding quality; welding production rate; no oxygen dehydrogenase reaction (easy to form welding defects, welding particularly demanding surface cleaning); wind capacity; welding equipment complex.
Applications - almost all of the weld metal, mainly used for non-ferrous metals and alloys, stainless steel and certain alloy steel (too expensive) welding. Thinnest thickness of about 1 mm, the thickness of the basic large unrestricted.
5, TIG welding (tungsten inert gas welding)
Principle - in an inert gas, the use of tungsten and arcing between the Welding Cable parts melt of base metal and filler wire (not to add filler wire) to form a seam welding method.
Key Features - adaptability (arc stability, no splash); welding production rate (current carrying capacity of less tungsten (melting and evaporation of anti-tungsten, tungsten anti-weld clip)); production costs higher.
Applications - almost all metal welding materials, commonly used in stainless steel, high temperature alloys, aluminum, magnesium, titanium and its alloys, refractory active metals (zirconium, tantalum, molybdenum, niobium, etc.) and different bell metal welding. Welding thickness of 6 mm below the welding parts, welding or thick pieces of the primer.
6, plasma arc welding
Principle - water-cooled nozzle with the binding effect of the arc, to obtain high energy density plasma arc welding method.
Main features (and TIG ratio) - (1) energy concentration, high temperatures for most metals in a certain range of thickness effects have access to the hole, you can get full penetration, negative forming uniform weld. (2) arc stiffness, is basically a cylindrical plasma arc, arc welding pieces of change and current density of the heating area is relatively small. Therefore, changes in plasma arc welding of significant effect on the weld. (3) TIG welding speed faster than that. (4) to weld thinner, thinner workpiece. (4) equipment complex and expensive.