First of all welded pipe weld clean oil, paint, water, rust, etc., and then open the groove according to the thickness, to open a large number of thick, thin it to open a small number of (angle grinder, then that is the gap of product, generally 1- 1.5 times the diameter of the rod or wire, if you are not careful groove open big words can be appropriate to stay smaller. tack welding at least three points, four points better work in general.
Welded steel pipe welding time should be half and half, the best starting point than the lowest point of about one centimeter, as well from the opposite connector. If the pipe wall thickness, it should be layered, at least two layers, the first layer of the whole circle of welding can weld finished second layer.
Welding technology of welded steel pipe
1, high-frequency resistance welding utilizing the skin effect and proximity effect of high frequency current, rapid heating tube strip edge so as to achieve a molten state, under the action of the squeegee roller pressing the welding metal fusion method.
2, the method of submerged arc welding arc welding arc coverage achieved in the flux. Weld metal bath in the flux coating to protect the weld solidification into flux cooling of the molten slag layer covering the outer surface of the shell welds.
3, tungsten inert gas welding use pure tungsten or tungsten activation (thorium tungsten, cerium tungsten, etc.) as an inert gas shielded arc welding electrodes as tungsten inert gas welding, the English referred to as TIG welding. It is under the protection of inert gas, the use of a welding method between the tungsten electrode and the weldment arc generated hot melt base material and filler wire.
4, metal inert gas welding wire is melted using inert gas welding electrodes.
5, CO2 gas shielded arc welding with a purity of> 99.8% CO2 shielding gas for MIG welding.
6, the mixed gas shielded arc welding of two or more gases, a mixed gas composed of certain proportion of gas as the shielding gas welding; TIG: using argon as protective gas arc welding.
7, pulse welding current to maintain the use of the base value of the main arc of the plasma channel, and periodically add together the polar peak pulse current pulse arc to melt the metal and welding control droplet transfer.
8, plasma arc welding and binding effect by means of a water-cooled nozzle arc, higher energy density plasma arc welding methods.
9, soldering heat welding process, the low melting point metal material than the base material for the solder, the solder weldment and heated above the solder melting point, below the melting point of the base material, the use of liquid solder wetting parent material, filling the gap and connect with the base metal interdiffusion connect weldment method called brazing. Commonly used methods for composite brazing induction brazing.