Galvanized square pipe is a kind of special pipe with hollow cross-section, and it is because of this special design that the application of this kind of pipe in our life has a lot of expansion. Especially in our shipbuilding and construction industry, but also in the military, aviation field is also a great development. Galvanized square tubes are divided into hot-dip galvanized square tubes and cold galvanized square tubes in terms of production process. It is because of the two kinds of galvanized square tube processing method is different also creates a lot of different physical and chemical properties. We have to use correctly and reasonably to play the role of galvanized square tube. In general, they have a lot of differences in strength, toughness and mechanical properties.

Hot-dip galvanized square tube

Hot-dip galvanized square tube: it is a square tube made by welding after using steel plate or steel strip coiled and formed, and on the basis of this square tube, the square tube is placed in a hot-dip galvanized pool after a series of chemical reactions and then formed a kind of square tube. Hot-dip galvanized square pipe production process is relatively simple, and the production efficiency is very high, the variety of specifications are also many, this kind of square pipe requires very little equipment and capital, suitable for small galvanized square pipe manufacturers. But in terms of strength this steel pipe is much lower than the seamless square pipe.

Cold galvanized square tube

And cold galvanized square tube is the use of cold galvanizing on the square tube used to make the square tube have anti-corrosion properties. Unlike hot-dip galvanizing cold galvanizing paint is mainly through the electrochemical principle of corrosion protection, so it is necessary to ensure that the zinc powder and steel full contact, resulting in an electrode potential difference, so the surface treatment of steel is very important.

Difference between hot and cold galvanized square tube

Galvanized square tube has two categories: hot-dip galvanized square tube and electro-galvanized square tube. Hot-dip galvanized square tube has wet method, dry method, lead-zinc method, redox method, etc.. The main difference between different hot-dip galvanizing methods in the steel pipe after acid dip cleaning, with what method to activate the surface of the pipe body to improve the quality of galvanization. Now the production is mainly used in the dry method and redox method, its characteristics are shown in the table. Electro-galvanized zinc layer surface is very smooth and dense, uniform organization; has good mechanical properties and corrosion resistance; zinc consumption than hot-dip galvanized low 60% to 75%. Electro-galvanizing has a certain degree of technical complexity, but for single-sided plating, double-sided plating with different thicknesses on the inner and outer surfaces, and galvanizing of thin-walled tubes, etc., this method must be used.