Can galvanized steel pipe be welded?
As long as the welding conditions such as welding material, welding surface, welding current, welding speed, and welding method are appropriate, galvanized steel pipes can also be welded. However, it should be noted that after the galvanized steel pipe is welded, the welded galvanized layer should be polished and smoothed, otherwise the quality of the galvanized steel pipe will be affected, and it will easily cause blistering and oxidation of the galvanized steel pipe.
Generally, the welding strength of steel pipes does not weaken, but with the increase of galvanized thickness, the range of appropriate welding conditions becomes narrow, which makes welding difficult. Therefore, it is best to completely remove the zinc from the welded part during welding.
Welding skills of galvanized steel pipe:
The preparation of galvanized steel pipe before welding is the same as that of general welded pipe. It should be noted that the groove size and the nearby galvanized layer should be carefully handled. For penetration, the groove size should be appropriate, generally 60-65°; a certain gap should be left, generally 1.5-2.5mm; in order to reduce the penetration of zinc into the weld, before welding, the galvanized galvanized material in the groove can be Solder after the layer is removed. In the actual supervision work, the centralized beveling process without blunt edge is adopted for centralized control, and the two-layer welding process reduces the possibility of incomplete penetration. The electrode should be selected according to the base material of the galvanized steel pipe. Generally, J422 is more common for low carbon steel due to its ease of operation.
Welding method: When welding the weld of multi-layer welding, try to melt the zinc layer and make it vaporize and evaporate to escape the weld, which can greatly reduce the liquid zinc remaining in the weld. When welding fillet welds, also try to melt the zinc layer and make it vaporize and evaporate to escape the weld. The method is to first move the end of the electrode forward about 5-7mm, and after the zinc layer is melted, Return to the original position and continue to weld forward. In horizontal welding and vertical welding, if short slag electrodes such as J427 are used, the undercut tendency will be very small; if the back and forth transportation technology is used, defect-free welding quality can be obtained.
When welding galvanized steel pipes, the following points must be paid attention to:
1) A lot of smoke is generated during welding, and welding workers will have adverse emotional effects when inhaled, so they must wear masks or install smoke exhaust equipment;
2) After welding, the welding slag must be removed, and the peeling part of the zinc layer should be repaired with high zinc-containing paint or repaired with zinc welding.
It can be seen that there is no special problem with welding. However, on-site welding is always harmful to the appearance, so bolts are used as much as possible.
Hot-dip galvanized steel pipe is used for transportation and construction. Hot-dip galvanizing is a process technology that immerses steel, stainless steel, cast iron and other metals into molten liquid metal or alloy to obtain a coating. It is the most widely used in the world today and has the best performance-price ratio The surface treatment method of steel pipe.