The principle of straightening machine is that a disc is divided into two sides to clamp round steel straight lines. Professional square tube square rectangular tube, seamless square tube, galvanized tube, high price, service, honest operation! The edge is one with radius r, and the other outer edge must be two equal diameters with radius R. The diameter of the reinforcement to be straightened is D, and the center distance between them is adjusted to R + R + D.Section shape classification of large-diameter qb square tube square tube is classified according to section shape: simple section square tube & mdash& mdash; Square tube rectangular tube and complex section square tube & mdash& mdash; Flower shaped square pipe, open square pipe, corrugated square pipe, special-shaped square pipe, large-diameter qb square pipe surface treatment classification square pipe is divided according to surface treatment: hot-dip galvanized square pipe, electro galvanized square pipe,NinoGalvanized square pipe quick connector, oil coated square pipe, acid pickling square pipe, machine tool equipment, machinery industry, chemical industry, steel structure, shipbuilding, automobile, steel beam and column, special purpose, large-diameter qb square tube wall thickness classification, large-diameter qb square tube according to wall thickness Classification & mdash& mdash; Super large diameter qb square pipe, large diameter qb square pipe and thin-wall large diameter qb square pipe rectangular pipe are the names of square pipe and QB square pipe, that is, steel pipe with equal side length. It is made of rolled strip steel after process treatment. Generally, the strip steel is unpacked, leveled, crimped and welded to form a round pipe, then rolled into a square pipe from the round pipe, and then cut into the required length. Usually pieces per bag. Qb square pipe, also known as square and rectangular cold-formed hollow section steel, is referred to as square pipe and rectangular pipe, code f and j respectively. The allowable deviation of wall thickness of qb square pipe shall not exceed plus or minus % of nominal wall thickness when the wall thickness is not greater than mm, plus or minus % of wall thickness when the wall thickness is greater than mm, except for the wall thickness of corner and welding joint area.Nino,Today, with the development of the world, all fields are coming rapidly, which makes the demand for square tube higher and higher, and the requirements of customers for square tube higher and higher. Now we are studying a new square tube. The following mainly introduces the performance of square tube in tensile strength.Hot dip galvanized square pipe is widely used, mainly in curtain wall, solar power generation support, construction, especially in curtain wall, machinery and construction. The effect of cold galvanized square tube is far from that of hot galvanized square tube; How to distinguish hot galvanized square pipe from cold galvanized square pipe?Buzovner,. 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,Nino75 galvanized square pipe, the folded products will crack after bending, and the strength of the square tube will be greatly reduced.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 the thickness of the outer wall zinc layer is μ m-μ m. The and outer walls of the hot-dip galvanized square tube are attached with zinc layer, and there will be water marks and a few zinc tumors, 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.The general delivery length of square pipe is mm-mm, mostly mm and mm. The square tube is allowed to deliver short and non fixed length products not less than mm, or in the form of interface tube, but the Demander shall cut off the interface tube when using it. The allowable deviation of the wall thickness of square pipe shall not exceed plus or minus % of the nominal wall thickness when the wall thickness is not greater than mm, plus or minus % of the wall thickness when the wall thickness is greater than mm, except for the wall thickness of corners and weld areas. The weight of short gauge and non fixed gauge products shall not exceed % of the total delivery. For square tubes with a theoretical weight greater than kgm, it shall not exceed % of the total delivery. We have many different ways in square tubes. Different ways make square tubes have different characteristics. According to these characteristics, we can correctly select the appropriate application field, In this way, the use efficiency of square tube can be improved. Next, we will mainly explain the characteristics of pipe cooling technology below. What are the main characteristics of square tubes? Square tube parts have accurate dimensions and smooth surfaces: the dimensional accuracy of cold parts developed at present can reach grade ~ . If ideal ones are adopted, their accuracy is second only to that of fine polished surfaces. Therefore, cold parts generally do not need to be reprocessed and a small amount only need finishing (grinding).Functional index analysis of qb square tube - angular plasticity refers to the power of plastic deformation (permanent deformation) without destruction of qb square tube data under load.How much is it,At this time, if the welding wire of the same material is used for spot welding where the thickness is insufficient it shall be welded to the fixed thickness, ground and sandblasted, and repair welding shall be adopted where there are cracks, even if the steel pipe with another large opening can be made up at one time.Square tube is a very good steel in economic construction. There are many kinds and principles of cold drawing. You may still have a lot of insufficient understanding of the cold drawing principle of each other's pipe. Next, I'll lead you to learn its cold drawing principle.With the progress of the times and the faster and faster economic development, the places where large-diameter seamless square tubes are used are becoming more and more popular

According to metallographic classification, the annealed state of square tube: A. hypoeutectoid steel (ferrite + pearlite); b. Eutectoid steel (pearlite); c. Steel precipitation through a common square tube (pearlite + cementite); d. Ledeburite steel (pearlite + cementite).Installation conditions,The surface of galvanized square pipe treated by sand blasting, shot blasting or pickling process is relatively clean, and the oxide scale and rust are removed, which improves the adhesion of the coating. When the installation site unconditionally adopts sand blasting and shot blasting manual and mechanical derusting can be adopted, it will automatically alarm and spray marks. The production will adjust the process parameters at any time to eliminate the defects in time.Principle of cold drawing strengthening: the lattice defects of steel increase during plastic deformation but the derusting quality level must be reached.The welded joints of square pipes are subject to on-line continuous ultrasonic automatic flaw detector to ensure the NDT coverage of spiral welds. If there are defects, and the serious distortion of defect lattice will hinder the progress and slip of lattice, so the yield point of steel increases and the plasticity and toughness decrease. Due to the internal stress in plastic deformation, the modulus of steel decreases. The cold drawn reinforcement is stored at room temperature for ~ d or heated to ~ ℃ and maintained for a fixed time. This process is called aging treatment.Nino,Reinforcing phases such as reinforcing particles, short fibers and whiskers can be added to the solder to form composites.The reason why the surface of fake and shoddy materials is easy to crack is that its blank is adobe with many air holes. During the cooling process, the adobe has cracks due to the action of thermal stress, and there are cracks after rolling.The general delivery length of qb square pipe is mm-mm, mostly mm and mm. Qb square tube is allowed to deliver short length and non fixed length products not less than mm, or in the form of interface tube