Description

Galvanized square pipe is a hollow steel with a square cross-section that can be made by two different processes. One method is to use hot-rolled or cold-rolled galvanized strip steel or galvanized coil as raw materials, through cold bending processing, and then use high-frequency welding technology to make it into a fixed size square cross-section shape. The other method is to hot-dip galvanized the cold formed hollow steel pipe, so as to obtain galvanized square rectangular pipe.

Galvanized square pipe can be divided into hot galvanized square pipe and cold galvanized square pipe according to the different production process two categories. Due to the differences in processing methods, these two galvanized square pipes have significant differences in physical and chemical properties. In terms of strength, toughness and mechanical properties, both have their own characteristics and advantages.

Hot-dip galvanized square pipe:

Hot-dip galvanized square pipes are made by crimping steel plates or steel strips into the shape of square pipes and welding them, and then placing these square pipes into a hot-dip galvanized pool after a series of chemical reactions. The production process of hot-dip galvanized square pipe is relatively simple, the production efficiency is high, and the product specifications are diverse. The production of this kind of square pipe requires less equipment and capital investment, which is very suitable for smaller galvanized square pipe manufacturers. However, from the point of view of strength, the strength of this steel pipe is usually lower than that of seamless square pipe.

Cold galvanized square pipe:

Cold galvanized square pipe is based on the original square pipe, using the principle of cold galvanized to give the square pipe anti-corrosion performance. Different from hot-dip galvanizing, cold galvanizing mainly relies on electrochemical principles to achieve anti-corrosion effects. Therefore, it is necessary to ensure that the zinc powder is in full contact with the steel surface to form the electrode potential difference, which requires the treatment of the steel surface to be very important.

Difference between hot and cold galvanizing:

Galvanized square pipe is mainly divided into hot dip galvanized square pipe and electric galvanized square pipe two types. Hot-dip galvanized square pipe has a variety of different treatment methods, including wet method, dry method, lead-zinc method, REDOX method and so on. The main difference between these different hot dip galvanizing methods is what method is used to activate the surface of the pipe after the acid dip cleaning to improve the quality of galvanizing. At present, the production process mainly uses dry method and REDOX method. The surface of zinc layer of electrogalvanized square pipe is very smooth, compact and uniform, and has good mechanical properties and corrosion resistance. Electrogalvanizing can save 60% to 75% zinc consumption compared to hot dip galvanizing. Although electrogalvanizing is technically more complex, it is usually necessary to use electrogalvanizing methods for single-sided coating, double-sided coating with different thickness of internal and external surface coating, and thin-walled pipe galvanizing.