Zinc coated steel pipe processing technology in a mill

Today, galvanized steel pipes have large market sales each year in the steel market. In view of production processing technology, galvanized pipe is divided into two kinds: electro galvanized pipe and hot dip galvanized pipe. In life, people are generally used to call the hot dipped galvanized pipe as galvanized pipe. Roughly speaking, hot dip galvanized pipe has more performance advantages than the electro galvanized pipe. Besides, due to the higher processing costs, the steel pipe price is a little more expensive than that of electro galvanized pipe. As a rule, when compared with hot dipped galvanized steel pipe, rectangular steel pipe has not so good property on the whole, particular the property of corrosion resistance. In recent years, because of the national policy, electro galvanized pipe has been eliminated from the steel market.

When it comes to galvanized pipe, we have to know about the term “galvanization”. Hot dipped galvanized steel pipe will undergo the processing where there will formed a layer of alloy around the pipes due to the physical reaction between the molten zinc and iron. As a result, this type of pipe has a stronger corrosion resistance than other common types. In addition, the steel pipe has a very uniform coating with strong adhesion property of zinc layer so as to greatly extend the service life of the pipes. Furthermore, compared with other frequent pipes, hot dipped galvanized steel pipe has a lot of obvious advantages in a wide range of actual purposes in life.

Technically speaking, galvanization is related to apply a protective zinc coating to the steel or iron pipe body, in order to prevent rusting. Hot-dipped galvanizing is the most common method of galvanization, in which the pipe bodies are submerged in a bath of molten zinc. In general, according the raw materials of pipes, galvanized pipe has two categories: pre galvanized pipe and hot dipped galvanized steel pipe. The pre galvanized pipe refers to the welded pipe which has undergone degreasing, rust removal, phosphorization, and drying processes before galvanization. The treatments before galvanization allow the product to be conveniently plated with a zinc coating, and also ensure uniform coating thickness, strong coating adhesion, and improve corrosion resistance. Pre galvanized pipes are widely used in heat, water and natural gas supply systems, agricultural greenhouse construction field, steel structure construction field as well as low and medium pressure piping system.