In the current steel market, with a new round of galvanized steel pipe prices rise, it means galvanized steel pipe has become much more popular with people in life today. Galvanized steel pipe generally has the rational cost effective in the market. Compared with other typical steel pipe coatings, such as specialized painting and powder coating, galvanization is much more labor-intensive, resulting in a higher initial cost for contractors. Besides, due to its durability and anti-corrosive properties, galvanized steel pipe can recycled and reused, which to some degree save a lot of money during the post maintenance work.
In the steel pipe industry, pre galvanized steel pipe and hot dipped galvanized steel pipe are the two common types of galvanized steel pipe widely used in various applications so far. Roughly speaking, hot-dipped galvanization is a form of galvanization. It is the process of coating iron and steel with a layer of zinc by immersing the metal in a bath of molten zinc at a temperature of around 840 °F (449 °C). When exposed to the atmosphere, the pure zinc reacts with oxygen to form zinc oxide, which further reacts with carbon dioxide to form zinc carbonate, a usually dull grey, fairly strong material that protects the steel underneath from further corrosion in many circumstances. As zinc is a kind of toxic substance, it will produce a certain pollution and damage to the human body and the environment. Therefore, the increase in the cost of environmental protection is one of the important reasons for a higher steel pipe price in the current steel pipe market.
As a rule, there are four steps for galvanizing process in a mill as follows:
•Pre-inspection – where the fabricated structural steel is viewed to ensure it has, if necessary, the proper venting and draining holes, bracing, and overall design characteristics necessary to yield a quality galvanized coating
•Cleaning – steel is immersed in a caustic solution to remove organic material such as grease and dirt, followed by dipping in an acid bath (hydrochloric or sulfuric) to remove mill scale and rust, and finally lowered into a bath of flux that promotes zinc & steel reaction and retards further oxidation of the steel… (steel will not react with zinc unless it is perfectly clean)
•Galvanizing – the clean steel is lowered into a kettle containing 850 F molten zinc where the steel and zinc metallurgically react to form three zinc-iron intermetallic layers and one pure zinc layer
•Final inspection – the newly galvanized steel is sight-inspected (if it looks good, it is), followed up by measurement of coating thickness with a magnetic thickness gauge
Dong PengBoDa Steel Pipe Group is one of famous steel pipe manufacturers in China. We are committed to producing various types of steel pipe for your choice in applications. If you have any need, please contact us.
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Post time: Oct-26-2018