Can galvanized steel pipes be welded?

Can galvanized steel pipes be welded?
Galvanizing is the process of coating steel with zinc. Galvanized steel pipes are widely used in agriculture and the construction industry because galvanizing can form a dense oxide protective layer to protect the steel structure inside the steel pipe. Can galvanized steel pipes be welded? Yes! In fact, their welding is no different from ordinary carbon steel pipes. However, due to the presence of galvanized layer, cracks, pores, and slag inclusions are prone to occur during welding, and the welding quality cannot be guaranteed.
 
Galvanized steel pipes can be welded using traditional arc welding. If welded correctly, there is not much difference in the welded mechanical properties of galvanized and non-galvanized steel pipes.

Galvanized pipe is often spot or resistance welded using special electrodes to minimize adhesion to the workpiece. First, the right welding material is a key factor in obtaining a perfect joint with good mechanical properties. J421, J422, J423 are ideal rods for galvanized steel. Second, remove the zinc coating before starting to weld. Grind the coating off the welded area plus 1/2 inch of zinc coating, then melt and apply it to the ground area. Moisten the area with spray penetrating oil. Use a new, clean grinder to remove the galvanizing.

After the protective and anti-corrosion measures are prepared, welding can be carried out. Welding is a high-temperature operation, and welding galvanized pipe can release harmful green fumes. Please note that this smoke is toxic to humans! If inhaled, it can give you a severe headache and poison your lungs and brain. Therefore, use a respirator and exhaust during welding and ensure good ventilation, and consider wearing an anti-particle mask.

Once the galvanized layer at the weld is destroyed. Apply some zinc-rich paint to the welded area. In practical applications, galvanized steel pipes with a diameter less than or equal to 100mm should be threaded, and the galvanized layer and exposed threaded parts damaged during the connection process should be treated with anti-corrosion treatments. Galvanized steel pipes with a diameter greater than 100mm should be connected with flanges or plugging fittings, and the welded parts of the pipes and flanges should be re-galvanized.