1. Red welding: red welding is the earliest developed and most widely used welding method among various arc welding methods. Manual red welding equipment is simple, light and flexible. It can be applied to the welding of short joints in maintenance and assembly, as well as the welding of parts that are difficult to reach. Manual welding can be applied to most industrial welding categories, such as carbon steel, stainless steel, cast iron, copper, aluminum and nickel.2. Tungsten gas shielded arc welding: pure argon is used for protection, and the purity is more than 99.99%, otherwise it will affect the surface color of weld bead and porosity. Generally, the extension length of tungsten electrode is as short as possible relative to the nozzle, and the arc length is 1-3mm. Arc welding uses the arc between tungsten electrode and workpiece to melt the metal to form weld. If tungsten electrode does not melt during welding, It only plays the role of electrode, and argon = gas is sent from the nozzle for protection. Tungsten gas shielded arc welding is an excellent method for connecting sheet metal and backing welding because it can well control heat input. This method can be used for almost all metal connections.
3. Gas metal arc welding: this welding method can not only achieve high-efficiency welding, but also easy to realize welding automation. It is widely used in surfacing, thin plate welding and other fields. Gas metal arc welding is easier to realize excessive spraying and make the arc more stable. At the same time, it can also improve the wettability of deposited metal and make the weld bead ripple beautiful. The commonly used protective gases are: gas CO2 gas or a mixture of these gases. Inert gas arc welding with argon or helium as shielding gas is called metal inert gas arc welding.4. Surfacing: hardfacing wear-resistant technology, i.e. surfacing, spraying or repair of metal surface. The most common problem in surfacing is cracking. The best prevention method is preheating before welding and slow cooling after welding. The preheating temperature and humidity are estimated according to the carbon equivalent of the welding material used. The carbon equivalent formula provided by IW (International Welding Society) is CEQ = C + 1 / 6MN + 1 / 24si + 1 / 5cr + 1 / 4mo + 1 / 15Ni, The performance of surfacing metal is related to the welding current and the length of arc. If the current is large and the arc is long, the alloy elements are easy to burn, otherwise it is too beneficial to the alloy elements.
5. Tubular wire arc welding: tubular wire arc welding also uses the arc burning between the continuously fed welding wire and the workpiece as the heat source for welding, commonly known as (flux cored wire). The main difference between tubular wire gas shielded arc welding and solid wire gas shielded welding is that the structure of the welding wire used is different. Flux cored wire is filled with flux and metal powder mixture in the welding wire, During welding, under the action of arc heat, the molten core material, welding wire metal, base metal and shielding gas have metallurgical effect with each other, and a thin layer of liquid slag is formed to cover the droplets and the molten pool, forming another layer of protection for the molten metal. It is a welding method of gas slag combined protection.6. Electroslag welding: electroslag welding is a welding method based on the resistance heat of slag. The welding process is at the vertical welding position and at the end face of two I pieces With the assembly gap formed by the water-cooled copper sliding blocks on both sides. During welding, the resistance heat generated by current through slag is used to melt the end of the workpiece. According to the electrode shape used in welding, electroslag welding is divided into wire electroslag welding, plate electroslag welding and nozzle electroslag welding. The advantages of electroslag welding are: large thickness of weldable workpiece (from 30mm to more than 1000mm) and high productivity. It is mainly used for welding butt joints and T-joints on section. Electroslag welding can be used for welding of various steel structures and assembly welding of castings. Electroslag welded joints are generally subject to normalizing treatment after welding due to slow heating and cooling, wide heat affected zone, coarse microstructure and toughness.
7. Gas welding: the selection of welding wire for gas welding and gas shielded welding shall be consistent with the chemical composition of the base metal and contain a certain amount of deoxidizing elements, such as manganese and silicon, so that the weld has certain mechanical properties. At the same time, it shall be considered that the welding wire shall not be strongly splashed and evaporated during welding, which is generally suitable for maintenance and single sheet welding.Shanghai Ruihan Welding Material Co., Ltd. is located in In the first China dream Valley Park in the west of Shanghai Hongqiao International Convention and Exhibition Center, it is committed to the R & D, production and sales of welding materials and provides overall welding solutions for various production fields. Ruihan has a number of production bases and has reached strategic cooperation with a number of welding material manufacturers at home and abroad. With the mission of "continuously improving customer service, shortening supply chain and reducing cost", Ruihan serves the manufacturing fields of pressure vessels, chemical equipment, biopharmaceutical, boilers, new electric energy, valves, ships, offshore engineering and so on.