The specific method instruction of welding red copper tube

The welding equipment is WS400 DC ARGON arc welding machine. The welding material is copper wire (wire 201) with a diameter of 3mm, and the purity of argon gas is ≥9.96%. (2) The groove pairs are not left with gaps. The groove pairs are shown in the figure below. The welding area of copper pipe and copper wire shall be free from oil, oxide layer, moisture and other metallic luster.

Welding parameters: tungsten electrode φ 3mm cerium tungsten electrode, nozzle medium 4mm, welding power 160 ~ 180 a, chlorine flow 15L/min. Preheating. Due to the large thermal conductivity of copper, large linear expansion coefficient, hot and brittle, the groove of copper pipe and the groove of 60 mm on both sides of the groove should be preheated before welding. Preheating method is oxyacetylene flame heating, preheating temperature is about 500℃, temperature measurement method is point contact thermometer.

Position welding of two pipe fittings (according to one third of pipe circumference, two position welding, one welding), position welding length ≥10 mm or above, welding height of 3 mm is appropriate. Welding The welding layer consists of two layers, the bottom layer and the top layer, both of which are rotary welded. The welding position is between 10 o 'clock and 11.30 o 'clock and is welded upwards by random rotation.

The left hand welding method is adopted for back welding and back welding. Defects such as porosity, slag inclusion, flapping and incomplete penetration should be prevented during welding. The Angle between the wire and the pipe plane should be as small as possible to enhance the effect of argon protection. The Angle between the wire and the tungsten needle is about a right Angle. The welding torch should move evenly, and the molten pool temperature should be properly controlled, not too high or too low, so that the welding process can proceed smoothly.