Galvanized pipes are divided into heat -galvanized steel pipes and cold -galvanized steel pipes, of which cold galvanized steel pipes have been gradually eliminated.
1. Hot -dip galvanized pipe/hot -dip galvanized steel pipe
The hot -dip galvanized metal reacts with the iron -based reaction to generate the alloy layer, which combines the substrate and the coating. The manufacturing of hot -dip galvanized pipes is to pick up the steel pipes first to remove the iron oxide on the surface of the steel pipe. After pickling, clean it through ammonium chloride or zinc chloride water solution or ammonium chloride and zinc chloride hybrid water solution. , And then send it to the hot immersion groove.
The hot -dip galvanized steel pipe is a complicated physical and chemical reaction between the steel pipe matrix and the melting plating fluid, forming a tight zinc iron alloy layer with corrosion resistance. The alloy layer is integrated with the pure zinc layer and the steel pipe matrix. Therefore, the hot -dip galvanized steel pipe has the advantages of uniform plating, strong adhesion, and long service life.
2. Cold galvanized pipe/cold galvanized steel pipe
Cold galvanized is electroplating. The amount of galvanizing is very small, only 10-50g/m2. Its corrosion resistance itself is much different than hot -dip galvanized pipes. In order to ensure the quality, the formal galvanized pipe manufacturers do not use electroplating (cold galvanized). Only those small and old -fashioned small companies use electroplating, of course, their prices are relatively cheap. The zinc layer and steel pipe matrix of cold galvanized steel pipes are layered independently. Because the zinc layer is thin, the zinc layer is simply attached to the steel pipe matrix and is easy to fall off. Therefore, the corrosion resistance of cold galvanized steel pipes is poor. Therefore, in the newly built houses, cold galvanized steel pipes have been prohibited as water supply and gas pipes.
The production process of galvanized pipes
The production process of galvanized steel pipes belongs to the secrets of various manufacturers, so it can only provide a general process process: A. Reading steel preparation; B. Heating; C. Hot -rolled perforation; D. Cut head; E. Picky; f. Repair; G. Lubrich; h. Cold rolling processing; i. Skin; J. Solid -soluble heat treatment; k. Straighten; l. Cut the tube; m. Picky; n. Product testing.
