Large diameter qb square tube production standard classification square tube is divided according to production standard: national standard square tube, Japanese standard square tube, British standard square tube, American standard square tube, European standard square tube and non-standard square tube.The square tube for fluid transportation (gbt-) is a general square tube for transporting water, oil, gas and other fluids.Knoke robbery,The banding caused by component segregation is difficult to be eliminated by heat treatment. Generally, normalizing can reduce this segregation to a certain extent. Generally,Knoke robberyDN50 galvanized pipe, normalizing can correct the segregation to the allowable level. If the banding is serious, it can be improved by multiple normalizing. It is reliable to conduct high-temperature diffusion annealing first and then normalize again,Knoke robberyGalvanized square pipe 4, which can completely eliminate the strip, but the cost will be very high, which is difficult to achieve for the steel plate due to the surface quality.Due to the increase of square tube production, there are more and more fake and shoddy square tubes in the market. How to distinguish the fake and shoddy square tubes? Let me teach you some points to distinguish the fake and shoddy square tubes.Thane,Carbon steel classified by chemical composition: square tube A. low carbon steel (C & le; .%); b. Medium carbon steel (C & le; . ~ .%); c. High carbon steel (C & le; .%).A. square tube structural steel: (a) high quality carbon structural steel; (b) Alloy structural steel; (c) Spring steel; (d) Easy cutting steel; (e) Bearing steel; (f) High quality structural steel for specific purposes.High quality steel (P & le; .%, S & le; .%)

Square tubes for low and medium pressure boilers (gb-) are high-quality carbon structural steel hot-rolled and cold drawn (rolled) square tubes for superheated steam tubes, boiling water tubes for low and medium pressure boilers of various structures and superheated steam tubes large smoke tubes, alloy steel and stainless heat-resistant steel square tube for the heating surface of water tube boilers with high pressure and above. High pressure square tube for chemical fertilizer equipment (GB - is a high-quality carbon structural steel and alloy steel square tube suitable for chemical equipment and pipelines with working temperature of - ~ ℃ and working pressure of ~ mA.Galvanized qb square pipe for low pressure fluid transmission small smoke tubes and arch brick tubes for locomotive boilers. Square tubes for high-pressure boilers (gb- is a high-quality carbon steel, Standard No.: gbt-. The representative materials are the same as above. It is mainly used to transport low-pressure fluids such as water, gas, avoid the micro of thermal sensitive materials, and maintain the properties of materials.index, sampling quantity, sampling position and test of square tube shall be in accordance with the provisions of corresponding product standards. With the consent of the demander, hot-rolled square tubes can be sampled in batches according to the rolled root array.Ferrous metals refer to iron and iron alloys. Such as steel, pig iron, ferroalloy, cast iron etc. Steel and pig iron are alloys based on iron square tube and carbon as the main added element, collectively referred to as iron carbon alloy.The strength, plasticity and hardness discussed above in fatigue QB are the indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.

With the improvement of production quality, the quality of square tubes is getting better and better. The quality of square tubes will affect our lives. Because the functions of square tubes are different, their characteristics and uses are different. I will introduce the characteristics and uses of square tubes in detail.Safety and health,Hot dip galvanized square tube is a kind of square tube which is welded after using steel plate or steel strip to curl and form, the square tube is placed in the hot dip galvanized pool and formed through a series of chemical reactions; The production process of hot-dip galvanized square pipe is relatively simple, but the production efficiency is very high and there are many specifications and varieties, but this kind of square pipe needs little equipment and capital, which is more suitable for the production of small galvanized square pipe manufacturers.The advantages of real bending are small reverse, accurate forming, and as long as the roll shape is accurate,Knoke robberySpecification list of rectangular galvanized square pipe, the R of inner corner forming is more accurate. The disadvantage of solid bending is that it has tensile thinning effect. The actual bending will produce tension at the bending point, and the tensile effect will shorten the longitudinal length of the bending line; The metal at the real bend will become thinner due to stretching.Carbon steel classified by chemical composition: square tube A. low carbon steel (C & le; .%); b. Medium carbon steel (C & le; . ~ .%); c. High carbon steel (C & le; .%).Knoke robbery,The difference between square pipe and seamless steel pipe the main feature of seamless steel pipe is no welding joint and can withstand large pressure. The product can be very rough as cast or cold drawn parts.The square tube for fluid transportation (gbt-) is a general square tube for transporting water, oil, gas and other fluids.Hundreds of degrees Celsius, which can save energy.