1. Electrode arc welding:
Principle - Arc welding method with manual operation of the electrode welding. The stable burning arc established between the electrode and the weldment is used to melt the electrode and the weldment so as to obtain a strong welded joint. It is gas-slag combined protection.
Main features - flexible operation; Low assembly requirements for welded joints; Weldable metal material wide; Low welding productivity; Strong dependence on weld quality (depends on the welder's operating skills and field play).
Application - widely used in shipbuilding, boiler and pressure vessel, machinery manufacturing, building structure, chemical equipment and other manufacturing and maintenance industries. It is suitable for welding of all kinds of metal materials, all kinds of thickness and all kinds of structural shapes.
2. Submerged arc welding (automatic welding) :
Principle - The arc burns under the flux layer. The heat generated by the burning arc between the wire and the weldment is used to melt the wire, flux, and base metal (the weldment) to form a weld. It is slag protection.
Main features - high welding productivity; Good weld quality; Low welding cost; Good working conditions; It is difficult to weld in spatial position; High quality requirements for weldment assembly; Not suitable for welding thin sheet (welding current less than 100A, arc stability is not good) and short weld.
Application - widely used in shipbuilding, boiler, bridge, lifting machinery and metallurgical machinery manufacturing. Submerged arc welding can be used in welds where the weld can be kept horizontal or the inclination Angle is not large. Plate thickness must be greater than 5 mm (burn through). Welding carbon structural steel, low alloy structural steel, stainless steel, heat-resistant steel, composite steel, etc.
3, CO2 Shielded Welding Torch (automatic or semi-automatic welding) :
Principle: Fusion electrode arc welding using carbon dioxide as a protective gas. It is gas protection. Main features - high welding productivity; Low welding cost; Small welding deformation (arc heating concentrated); High welding quality; Simple operation; High splash rate; It is difficult to weld with AC power; Poor wind resistance; Non - ferrous metals which are easily oxidized cannot be welded.
4, MIG/MAG welding (melting extremely inert gas/active gas welding) :
MIG welding principle -- an arc welding method using inert gas as protection gas and welding wire as melting electrode. The shielding gas is usually argon or helium or a combination thereof. MIG uses an inert gas, while MAG adds a small amount of active gas, such as oxygen and carbon dioxide gas, to the inert gas.
5. TIG welding (tungsten inert gas shielded welding)
Principle - Under the protection of inert gas, using the arc generated between the tungsten pole and the weldment to melt the base metal and the filler wire (or no filler wire) to form a welding seam. Electromelting is extremely low during welding.
6. Plasma welding
Principle -- A method of welding plasma arc with high energy density by means of the constraint effect of water cooled nozzle on the arc.
1、the length of the arc
The arc length is related to the type of electrode coating and the thickness of electrode coating. But all should be taken as short arc as possible, especially low hydrogen electrode. Long arcing may cause air holes. The short arc can avoid the harmful gases such as O2 and N2 from the atmosphere from invading the weld metal, forming bad impurities such as oxides and affecting the quality of the weld.
2. Speed of welding
The appropriate welding speed is based on the diameter of the electrode, the type of coating, welding current, the heat capacity of the welded object, the beginning of the structure and other conditions have their corresponding changes, can not be made standard provisions. Keep proper welding speed, molten slag can cover the molten pool well. All kinds of impurities and gases in the molten pool have sufficient time to emerge, to avoid the formation of slag inclusion and porosity of the weld. If the rod speed is too fast in welding, the shrinkage stress will increase when the welding part is cooled, so that the weld will have cracks.
The main points of welding wire selection
The selection of welding wire should be based on the type of steel to be welded, quality requirements of welding parts, welding construction conditions (plate thickness, groove shape, welding position, welding conditions, post-welding heat treatment and welding operation, etc.), cost and other comprehensive considerations.
welcome to our alibaba shop: