QB square tube is a product appeared in recent years, which mainly has strict tolerance and roughness for the dimensions of inner hole and outer wall. Production process classification of large-diameter qb square tube large-diameter qb square tube is divided into hot-rolled seamless square tube cold drawn seamless square tube, seamless square tube and qb square tube according to production process. Among them, qb square tube is divided into: (a) by process & mdash& mdash; Arc welded square pipe, gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Material classification of straight seam welded square pipe and spiral welded square pipe large diameter qb square pipe: plain carbon steel square pipe and low alloy square pipe. Ordinary carbon steel is divided into Q Q q SS, # steel, # steel, etc; Low alloy steels are divided into q Mn, Q, St-, etc.Steel for construction and engineering according to the classification of use without phase transformation or partial phase transformation of square tube: A. ordinary carbon structural steel; b. Low alloy structural steel; c. Steel reinforcement.St. Thomas,Spiral square pipe for low-pressure transmission (standard of the Ministry of petroleum), with the standard number of syt-. The representative material is qbqb and other carbon steel materials. It is mainly used for low-pressure transmission of water, oil, natural gas, heating and other pipelines.Square tube is an essential material for the construction and Realization of industrialization. It is widely used and has a wide variety. According to different section shapes, square tube is generally divided into sections, plates, pipes and metal products. In order to facilitate the production, ordering and supply of square tube and do a good job in operation and management, it is also divided into heavy rail, light rail, large section steel, medium section steel, small section steel and square tube cold bending Section steel, high-quality section steel, wire rod, medium and thick steel plate, sheet steel, electrical silicon steel sheet, strip steel, seamless steel pipe, square pipe, welded steel pipe, metal products, etc.Denov,The local heat release in the welding process of square tube can reduce the heat affected zone, avoid the micro of thermal sensitive materials, and maintain the properties of materials.Stage ( & mdash; )Generally, chemical and electrolytic methods are used

If the re inspection results are unqualified (including the items whose preliminary inspection results are unqualified and re inspection is not allowed), the supplier can submit them for acceptance one by one; Or re conduct heat treatment (the number of RE heat treatment shall not exceed times), and propose acceptance with a new batch.Surface adhesion resistance is an important feature of square tubes. At present square tubes are mostly used for transportation, so the adhesion resistance makes square tubes not stick during transportation.The load of impact toughness acting on the parts at a great speed is called impact load. It is specialized in products and renewable resources. Its business includes: square tube, square tube, galvanized square tube and galvanized tube. The ability of metal under impact load is called impact toughness.property right,. fake and inferior square tubes are easy to fold. Folding is a variety of broken lines formed on the surface of square tubes, and this defect often runs through the longitudinal direction of the whole product. The reason for the folding is that the fake and shoddy manufacturers pursue the rate, the reduction is too large, resulting in ears, folding occurs during the next rolling, the folded products will crack after bending, and the strength of the square tube will be greatly reduced.Square tube,St. ThomasDN65 galvanized pipe, modified square tube, square tube, QB square tube and hot-rolled square tube are qualified in quality inspection. The manufacturer adopts advanced equipment to ensure the quality of each product. Magnetic flux leakage testing for surface defects of square tubes is very similar to magnetic particle testing for square tubes, and its scope of application, sensitivity and reliability are stronger than magnetic particle testing. Indirect square forming process the traditional forming process of cold-formed square pipe is to gradually roll the hot-rolled steel coil multi stand forming unit into round pipe at room temperature, and then the shaping unit will roll the round pipe into square pipe, which is suitable for rolling small and medium-sized products. Rolling with this process & ldquo; Superb & rdquo; Square tube will show its inherent defects. Because the roll work in the bending process of this process is always concentrated at the point excessive stress concentration often shows microcracks in the bending process of profiles, which will lead to cracking in serious cases. The products with such defects have serious consequences when they are used in building steel structures. The study of the broken square tube column in the Hanshin earthquake in Japan shows that the corner microcrack is the main cause of the square tube fracture. At the same time, due to the different forming bending radians of products with different wall thickness, the universality of rolls is limited. The large-size cold-formed square tube used in the process adopts the advanced & ldquo; Direct Square & rdquo; The production process is to directly roll the hot-rolled steel coil into a square and rectangular shape at room temperature.Generally, chemical and electrolytic pickling are used for pickling treatment. Only chemical pickling is used for pipelines, which can remove oxide scale, rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes are safe, environmentally friendly and economical! The products are exported to foreign countries and are deeply trusted. Sometimes they can be used as reprocessing after sand blasting and rust removal. Although chemical cleaning can make the surface reach a certain cleanliness and roughness, its anchor lines are shallow and easy to pollute the environment.

Comprehensive classification ordinary steel A. carbon structural steel: (a) Q (b) Q (b); (c) Q( C)； (d) Q( B)； (e) Q.How many?,The second is to clean the surface of the opposite pipe. When cleaning the opposite pipe, square rectangular pipes seamless square pipes, galvanized square pipes, galvanized pipes are supplied in time and cost-effective. They have become the preferred brand of many wire products. Welcome to buy! It is used to remove oil and dust. It is only suitable for removing grease and dust on the surface of square pipe, which can not remove rust and oxide scale. Therefore, it can only be used as an auxiliary means in production.When we understand the causes of defects in the drawing process of qb square tube, we should constantly improve the technology in the subsequent production process, so that we can reduce the occurrence of defects.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.St. Thomas,The load of impact toughness acting on the parts at a great speed is called impact load. It is specialized in products and renewable resources. Its business includes: square tube, square tube, seamless square tube, galvanized square tube and galvanized tube. The ability of metal under impact load is called impact toughness.Square tube, modified square tube, square tube, QB square tube and hot-rolled square tube are qualified in quality inspection. The manufacturer adopts advanced equipment to ensure the quality of each product. Magnetic flux leakage testing for surface defects of square tubes is very similar to magnetic particle testing for square tubes, and its scope of application, sensitivity and reliability are stronger than magnetic particle testing. Indirect square forming process the traditional forming process of cold-formed square pipe is to gradually roll the hot-rolled steel coil multi stand forming unit into round pipe at room temperature, and then the shaping unit will roll the round pipe into square pipe, which is called indirect square forming process. The traditional roll forming process uses the method of fixed bending point position and variable bending radian to complete the corner forming of pipe blank, which is suitable for rolling small and medium-sized products. Rolling with this process & ldquo; Superb & rdquo; Square tube will show its inherent defects. Because the roll work in the bending process of this process is always concentrated at the point, excessive stress concentration often shows microcracks in the bending process of profiles, which will lead to cracking in serious cases. The products with such defects have serious consequences when they are used in building steel structures. The study of the broken square tube column in the Hanshin earthquake in Japan shows that the corner microcrack is the main cause of the square tube fracture. At the same time, the universality of rolls is limited. The large-size cold-formed square tube used in the process adopts the advanced & ldquo; Direct Square & rdquo; The production process is to directly roll the hot-rolled steel coil into a square and rectangular shape at room temperature.The first is to remove the rust of the square tube. When removing the rust of the square tube, the steel wire brush is mainly used to polish its surface, which can effectively remove the loose or rusty rust on the surface of the square tube.