The manufacturing process of galvanized pipes involves several steps, from the preparation of raw materials to the final galvanized treatment. The following is the general manufacturing process of galvanized pipe:
1. Raw material preparation: The first step in manufacturing galvanized pipes is to prepare raw materials, usually using cold-rolled steel strip as the base material. The steel strip is cut, crimped and welded to form the initial shape of the pipe.
2. Welding: The cut steel strip is connected into a tube by high-frequency induction welding or arc welding. Welding can be spiral welding for long welds or straight welding for short welds.
3. Size shaping: the welded pipe may have a certain shape and size deviation, so it needs to go through rolling, drawing or cold drawing process to make the size, shape and wall thickness of the pipe meet the standard requirements.
4. Cleaning: After dimensional shaping, there may be impurities such as grease and dust on the surface of the pipe, which need to be cleaned to ensure the adhesion of the subsequent galvanized layer.
5. Pickling: After cleaning the pipe may have oxides, in order to improve the adhesion of the galvanized layer, the pipe may be pickling treatment to remove surface oxides and rust.
6. Pretreatment: Before galvanizing, the pipe needs to be pre-treated, including surface treatment and drying, to prepare for galvanizing.
7. Galvanized: After pretreatment, the pipe is immersed in the molten zinc liquid, and a uniform zinc layer is formed on the surface of the steel pipe through chemical reaction or electrochemical method, so as to achieve the effect of galvanized.
