What are the testing items for hot-dip galvanized steel pipes

Hot-dip galvanized seamless pipes are generally coated with a layer of zinc on low-carbon steel, and the thickness of the zinc layer is generally 20um. The melting point of zinc is 419°C and the boiling point is about 908°C. During the welding process, zinc melts into a liquid.
1. Use indirect fusion methods such as French blue, threaded head, and combination.
2. The connection is made by welding. Because galvanized pipes are carbon steel pipes, the welding of galvanized pipes and stainless steel pipes is the welding of carbon steel and stainless steel, which is the welding of dissimilar materials. Before welding, the galvanized layer next to the groove should be removed. After soldering, brush with silver powder. There is a lot of information on welding carbon steel and stainless steel.

What are the hot-dip galvanized steel pipe inspection items? China Steel Inspection and Testing Engineers will answer your questions. General testing items include chemical element analysis (C, Si, Mn, P, S), galvanized layer weight, galvanized layer uniformity, tensile strength, lower yield strength, elongation after fracture, flattening (0° and 90° position), adhesion of galvanized layer.

The hot-dip galvanized steel pipe matrix undergoes complex physical and chemical reactions with the molten plating bath to form a corrosion-resistant zinc-iron alloy layer with a tight structure. The alloy layer is integrated with the pure zinc layer and the steel pipe matrix, so it has strong corrosion resistance. Galvanized steel pipes with DN < 100 are generally threaded, and galvanized steel pipes with DN > 100 are generally connected with clamps. Thread reducer is used to connect DN80 steel pipe and DN70 galvanized steel pipe.

Hot-dip galvanized steel pipe testing standards: GB/T 3091-2015 "Welded steel pipes for low-pressure fluid transportation"