special shaped square pipe is the general name of square pipes with other cross-section shapes except circular pipe. According to the different cross-section shape and size of steel pipe, it can be divided into special-shaped square pipe with equal wall thickness (code D), tools and mechanical parts. Compared with circular tubes, special-shaped tubes generally have large moment of inertia and section modulus, and have large bending and torsion resistance, which can greatly reduce the structural weight and save steel. Square tubes are an indispensable part of construction workPlasticity QB square plasticity refers to the ability of metal materials to produce plastic deformation (deformation) without deformation under load.Lustnau,Tensile strength: - yield strength: & Ge; elongation: & Ge; mechanical properties of seamless pipe: tensile strength: - yield strength: ≥ elongation: & Ge; mechanical properties of seamless pipe: tensile strength: - yield strength: ≥ elongation: & Ge; mechanical properties of seamless pipe: tensile strength: - yield strength: ≥ elongation: & Ge; mechanical properties of seamless pipe: tensile strength: - yield strength: ≥ elongation: & Ge; square tube belongs to low alloy series. It is one of the materials of seamless steel pipe. In low alloy materials, this material is ordinary. Square tube used to be called QB square tube.Functional index analysis of qb square tube - mechanical function of plastic square tube. Solid bending, as the name suggests, is to compact the bending. During real bending, the inner and outer rollers and the inner and outer walls of the pipe blank are compacted in both directions.Bam,The reason why it is divided into two types is that chemical cleaning can only clean the surface very thoroughly, and it is difficult to achieve the desired results in some fine cracks.It is the process of drawing the die hole of the rolled metal blank (shape,LustnauGalvanized pipe DN300, pipe, product, etc.) into a section to reduce the length and increase. It is mostly used for cold processing.Zinc layer thickness: there is a great difference between cold galvanized square pipe and hot galvanized square pipe in galvanizing process; Cold galvanized square pipes are prone to & ldquo; Electric burning & rdquo; The color of this part is gray and the zinc layer is thick. It is easy to form a current dead angle at the corner, resulting in an under current area. The zinc layer at this part is thin, and there is no zinc layer attached to the cold galvanized square pipe. The cold galvanized square pipe has no zinc lump and caking as a whole, but the overall zinc layer is thin, and there will be water marks and a few zinc tumors, but the overall zinc layer is thick, and the thickness of the zinc layer on the inner and outer walls of the square tube is -mu; M above. The nature of QB square tube!

Square tube is made of different materials. It needs qualified inspection by relevant staff before leaving the factory. Square tube has a wide range of uses. Its main field is not only the construction industry but also can be seen everywhere in our daily life. The service life of square tubes is mainly affected by surface treatment. I will explain the specific operations of surface treatment of square tubes.When the square tube is covered, the surface of the square tube shall be ventilated to avoid the collection of water vapor on the surface due to difficult volatilization.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, small smoke tubes and arch brick tubes for locomotive boilers. Square tubes for high-pressure boilers (gb- is a high-quality carbon steel, 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.A complete range of products,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, 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.Among them, qb square tube is divided into: (a) by process & mdash& mdash; Arc welded square pipe, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Straight seam welded square pipe, spiral weldingThe second is the pickling of the square pipe. Both chemical and electrolytic methods are used when pickling the square pipe. These two methods can remove the oxide skin of the square pipe.

Compared with other welding, square pipe welding has many advantages, mainly because of the exothermic reaction, the material only needs to be heated below the melting pointQuality inspection report,B. converter steel: (a) acid converter steel; (b) Basic converter steel. Or (a) bottom blown converter steel; (b) Side blown converter steel; (c) Top blown converter steel.The normal process flow is as follows: the round steel is perforated to form a tube embryo, then pickling is carried out, the black skin on the outer surface is washed off, and then grinding is carried out. After passing the inspection, the rolling mill or cold drawing and cold drawing are carried out. Annealing is required for wall reduction, but not for air drawing. After forming, annealing and straightening are carried out, these are the processes. Better manufacturers will perform whitening treatment during annealing to make the surface treatment more beautiful. The narrow blank of square pipe can produce welded pipe with larger diameter, compared with the straight seam square pipe with the same length, the weld length increases by %, and the production speed is low. Square pipes with large or thick diameter are usually made of steel blank directly, while small welded pipes and thin-walled welded pipes only need to be directly welded with steel strip. Then after simple polishing,LustnauGalvanized JDG pipe, wire drawing is OK. Therefore, straight seam welding is mostly used for relatively welded pipes, and spiral welding is mostly used for large-diameter welded pipes.The pipeline is only subject to chemical pickling, which can remove oxide scale, rust and old coating. Sometimes it can be used as the reprocessing after sand blasting. Although chemical cleaning can make the surface reach a certain cleanliness and roughness, its anchor lines are shallow and easy to pollute the surrounding environment. The square tube shall be submitted for acceptance in batches, and the batch rules shall comply with the provisions of corresponding product standards.Lustnau,Solution treatment and nondestructive testing sand rolling treatment and sand blasting treatment many manufacturers in the market do not do solution treatment and % penetration nondestructive testing, and many of them use sand blasting instead of sand rolling. After these steps are omitted the cost is greatly reduced.Among them, qb square tube is divided into: (a) by process & mdash& mdash; Arc welded square pipe,Lustnau46 price of galvanized square pipe, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Straight seam welded square pipe spiral weldingImprove the positioning and pre bending steps, if necessary to ensure that the web hunting problem does not occur when pressing parts. Change the shape of the surface pressure of the material to ensure the quality of the parts and avoid the non movement of the surface shape of the roll gap, resulting in uneven walking feeding.