The difference between hot dip galvanized steel pipe and cold galvanized steel pipe

Galvanized steel pipe is divided into two categories - hot dip galvanized steel pipe and cold galvanized steel pipe. Cold galvanized steel pipe is electro-galvanized steel pipe, the content of galvanized is very small, only about 10g to 20g per square meter, its corrosion resistance is not as good as hot-dip galvanized steel pipe; the corrosion resistance of hot-dip galvanized steel pipe is greater than that of cold galvanized steel pipe. Besides, what are the differences between the two? Let's take a look at the specific differences between them.

The difference between hot dip galvanized steel pipe and cold galvanized steel pipe

First: There is a big difference in the way they work. The zinc used in hot-dip galvanizing is obtained at a temperature of 450°C to 480°C; while the zinc in cold galvanized steel pipes is obtained by electroplating at room temperature.

Second: there is a big difference in the thickness of the galvanized layer between the hot-dip galvanized pipe and the hot-dip galvanized pipe.

Third: The surface smoothness of the two is different. The surface of cold galvanized steel pipe is much rougher than that of hot-dip galvanized steel pipe.

Fourth: Cold galvanized pipes and hot-dip galvanized pipes also have a big difference in price. In order to ensure the quality, the hot-dip galvanized steel pipe generally does not use the electro-galvanizing method; and those small-scale enterprises with relatively old equipment mostly use the electro-galvanizing method, so the price of the cold-galvanized steel pipe is higher. Lower than hot-dip galvanized steel pipe. The hot-dip galvanized pipes supplied by Xinteng Industrial Products MRO Mall are all produced by regular manufacturers, and the quality is guaranteed.

Fifth: The hot-dip galvanized steel pipe is galvanized all over the steel pipe, while the cold galvanized steel pipe is only galvanized on one side of the steel pipe.

Sixth: the adhesion of the two is also very different. The adhesion of cold galvanized steel pipe is worse than that of hot-dip galvanized steel pipe, because the steel pipe matrix and zinc layer of cold galvanized steel pipe are independent of each other, the zinc layer is very thin, and it is simply attached to the surface of the steel pipe matrix , it falls off easily.

The process of cold galvanized steel pipe is electroplating. The inner wall of the steel pipe is not galvanized, but only the outer wall of the steel pipe is plated with zinc; The state has made relevant regulations that the corrosion resistance of cold galvanized pipes is poor, the zinc layer is easy to fall off, and there are potential safety hazards, so they cannot be used as gas pipelines and water pipelines.

To sum up, the difference between the two lies in the thickness, smoothness, price, corrosion resistance and adhesion of zinc.