Copper welding
The methods of welding copper (which is generally called industrial pure copper) include gas welding, manual carbon arc welding, manual arc welding and manual argon arc welding, and large structures can also be automated welding.
1.The most commonly used copper gas welding welding is the butt joint, and the overlap joint and T joint should be used as few as possible. Two types of welding wires can be used for gas welding. One is a welding wire containing deoxygenation elements, such as wires 201 and 202; the other is a general copper wire and a cutting strip of the base material, and gas agent 301 is used as flux. Neutral flame should be used when gas welding copper.
2.The copper copper wire rod copper 107 is used for manual arc welding, and the welding core is copper (T2, T3). The edges of the welding should be cleaned before welding. When the thickness of the weldment is greater than 4 mm, preheating must be preheated before welding, and the preheating temperature is generally around 400~500℃. When welding with copper 107 welding rod, the power supply should be reversed by DC.
3.Short arcs should be used during welding, and the welding rod should not swing horizontally. The welding rod makes a linear motion reciprocating, which can improve the formation of the weld. The long weld should be gradually welded. The welding speed should be as fast as possible. During multi-layer welding, the slag between the layers must be completely removed. Welding should be carried out in a well-ventilated place to prevent copper poisoning. After welding, use a flat-head hammer to tap the weld to eliminate stress and improve the quality of the weld.
4.Manual argon arc welding of copper. When manual argon arc welding of copper, the wires used are wire 201 (special copper welding wire) and wire 202, and also use copper wire, such as T2.
Before welding, the oxide film, oil and other dirt on the welding edges of the workpiece and the surface of the wire must be cleaned to avoid defects such as pores and slag inclusions. The cleaning methods include mechanical cleaning and chemical cleaning. When the thickness of the butt joint plate is less than 3 mm, the bevel is not opened; when the plate thickness is 3 to 10 mm, the V-shaped bevel is opened, and the bevel angle is 60 to 70; when the thickness of the plate is greater than 10 mm, the X-shaped bevel is opened, The bevel angle is 60~70; to avoid unwelded, blunt edges are generally left. According to the plate thickness and bevel size, the assembly gap of the butt joint is selected within the range of 0.5 to 1.5 mm.
Manual copper argon arc welding usually uses DC positive connection, that is, tungsten electrode is connected to negative electrode. In order to eliminate air holes and ensure reliable fusion and penetration of the weld roots, it is necessary to increase the welding speed, reduce argon consumption, and preheat the weldment. When the plate thickness is less than 3 mm, the preheating temperature is 150~300℃; when the plate thickness is greater than 3 mm, the preheating temperature is 350~500℃. The preheating temperature should not be too high, otherwise the mechanical properties of the welded joints will be reduced.
There is also copper carbon arc welding, and the electrodes used for carbon arc welding include carbon essence electrodes and graphite electrodes. The welding wire used for copper carbon arc welding is the same as when gas welding. The base material can also be used to cut strips, and fluxes of copper such as gas agent 301 can be used.
Brass welding
1.The methods of brass welding include: gas welding, carbon arc welding, manual arc welding and argon arc welding. 1. Gas welding of brass Because the temperature of the gas welding flame is low, the zinc evaporation in brass during welding is less than when using electric welding, so gas welding is the most commonly used method in brass welding (thank you for paying attention to Dingding Automatic Welding).
The welding wires used for brass gas welding include: wire 221, wire 222 and wire 224. These welding wires contain elements such as silicon, tin, iron, etc., which can prevent and reduce the evaporation and burning of zinc in the molten pool, and are conducive to ensuring the weld. Performance and prevent air holes. Fluxes commonly used in gas welding brass include solid powder and gas flux. Gas flux consists of boric acid methyl fat and methanol; fluxes are such as gas agent 301.
2.Manual arc welding of brass In addition to copper 227 and copper 237, homemade welding rods can also be used for welding brass.
When brass arc welding, the DC power supply positive connection method should be used and the welding rod should be connected to the negative electrode. The surface of the weldment should be carefully cleaned before welding. The bevel angle should generally not be less than 60~70o. In order to improve weld formation, the welded parts should be preheated at 150~250℃. Short arc welding should be used during operation, without horizontal or forward and backward swing, only linear movement, and the welding speed should be high. Brass welded parts that come into contact with corrosive media such as seawater and ammonia must be annealed after welding to eliminate welding stress.
3.Manual argon arc welding of brass. Manual argon arc welding of brass can use standard brass wires: wire 221, wire 222 and wire 224, and materials with the same components as the base material can also be used as filler materials.
Welding can be done by direct current or AC. When using AC welding, the evaporation of zinc is lighter than when direct current is connected. Usually, preheating is not necessary before welding, and preheating is only when the thickness of the plate is relatively large. The welding speed should be as fast as possible. After welding, the welded parts should be heated at 300~400℃ for annealing to eliminate welding stress to prevent cracks in the welded parts during use.
4.Brass carbon arc welding When brass carbon arc welding, wire 221, wire 222, wire 224 and other welding wires are selected according to the composition of the base material. You can also use homemade brass welding wires to weld. The gas agent 301 or the like can be used as the flux in welding. The welding should be operated short arc to reduce zinc evaporation and burn damage.
Post time: Mar-10-2025