Generally, Hot-dip galvanization pipes in our production and life mainly react with molten metal and ferrite to produce alloy layer, so that the substrate and coating can be combined. Among them, hot dip galvanizing mainly involves pickling the surface of steel pipes, and such measures are mainly used to remove iron oxide on the surface of steel pipes. After acid pickling, the ammonium chloride aqueous solution or Zinc chloride aqueous solution is uniformly cleaned in the tank and then sent in the hot dip tank.
Hot-dip galvanization material has the characteristics of uniform coating and strong adhesion. Therefore, it is basically used in the process of producing galvanized steel pipes. Therefore, the matrix of this steel pipe has complex physical and chemical reactions, forming a corrosion-resistant zinc iron alloy layer. The strong corrosion resistance of it is due to the combination of galvanized iron sheet as a protective layer and steel pipe.
The range of galvanized steel pipes involved in daily life is relatively wide, so the performance requirements will be strict. At present, there are three types of models we usually see in the market: DN100, DN150, and DN200. These three types are more common in general construction projects, and there are also some differences in prices. There are many different specifications of galvanized steel pipe materials, and we can make judgments based on the place and direction of use. How can we distinguish the quality of galvanized iron sheet steel pipes?
- Classification and chemical composition of galvanized steel pipes. In the process of manufacturing galvanized steel pipes, the grade and chemical composition used must meet the black pipe grade and chemical composition specified in GB-3092.
- Select the production method of galvanized steel pipe, which shall be Hot-dip galvanization.
- Thread and pipe interface of galvanized steel pipes. Usually, the threads of threaded galvanized steel pipes should be made after galvanizing. Additionally, it should be noted that the requirements of YB822 need to be met. Steel pipe joints need to meet the regulations of YB238, and cast iron pipe joints need to meet the regulations of YB230, both of which need to be clear.
