1. Welding rod arc welding:
Principle - An arc welding method that uses a manually operated electrode for welding. A stable burning arc is established between the welding rod and the weldment to melt the welding rod and the weldment, thereby obtaining a firm welded joint. It is a gas-slag joint protection.
Main features - flexible operation; low requirements for assembly of welded joints; wide range of weldable metal materials; low welding productivity; strong weld quality dependence (depending on welder's operational skills and on-site performance).
Applications - Widely used in the manufacturing and repair industries of shipbuilding, boilers and pressure vessels, machinery manufacturing, building structures, chemical equipment, etc. Suitable for welding of various metal materials, various thicknesses, and various structural shapes (in the above-mentioned industries).
2. Submerged arc welding (automatic welding):
Principle - The arc burns under the flux layer. The weld is formed by the heat generated by the arc burned between the wire and the weldment, melting the wire, the flux, and the base metal (weld). It is slag protection.
Main features - high welding productivity; good weld quality; low welding cost; good working conditions; difficult to weld in space; high quality requirements for welding parts; not suitable for welding thin plates (arable stability when welding current is less than 100A) Not good) and short welds.
Applications - Widely used in shipbuilding, boilers, bridges, lifting machinery and metallurgical machinery manufacturing. Submerged arc welding is available for weldments where the weld can be held in a horizontal position or with a small angle of inclination. The thickness of the plate needs to be greater than 5 mm (anti-burn through). Welded carbon structural steel, low alloy structural steel, stainless steel, heat resistant steel, composite steel, etc.
3. Carbon dioxide gas shielded welding (automatic or semi-automatic welding):
Principle: A fusion arc welding method using carbon dioxide as a shielding gas. It is a gas protection. Main features - high welding productivity; low welding cost; small welding deformation (concentration of arc heating); high welding quality; simple operation; large spatter rate; difficult to weld with AC power supply; poor wind resistance; metal.
4. MIG/MAG welding (melting inert gas/reactive gas shielded welding):
MIG welding principle - an arc welding method using an inert gas as a shielding gas and a welding wire as a melting electrode. The shielding gas is usually argon or helium or a mixture thereof. MIG uses an inert gas, and MAG adds a small amount of an active gas such as oxygen, carbon dioxide gas or the like to an inert gas.
5, TIG welding (tungsten inert gas shielded welding)
Principle - Under the protection of inert gas, the welding method is formed by using the arc generated between the tungsten electrode and the weldment to melt the base metal and the filler wire (without filling the wire). The electrodes do not melt during the welding process.
6, Plasma arc welding
Principle - By means of the restraining effect of the water-cooled nozzle on the arc, a plasma arc with a high energy density is obtained for welding.