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,Greensboro46 galvanized square pipe, spiral weldingThe 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.Greensboro,The function index analysis of the square tube - the strength acts with great progress. The load on the parts is called the charge and trap load. The damage power of the square tube under the charge and trap load is called the charge and trap toughness.Generally, chemical and electrolytic methods are usedMustasaari,GreensboroHow much is a galvanized square tube,Functional index analysis of qb square tube - the load on the machine parts due to the great progress of strength is called the frontal collapse load. The power of destruction of qb square tube under the frontal collapse load is called the frontal collapse 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, 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.The other is designed with deformation angle, which can be regarded as DEG from round tube to square tube; To & deg; The bending deformation of angle, so the deformation angle & theta; It can accurately reflect the deformation degree of corners and edges. In the design process, considering the influence of dimensional accuracy and metal work hardening, the distribution of deformation angle is usually larger at the beginning and middle passes, and then gradually decreases. In the pass formed directly by arc intersection, the fillet part of the pipe blank cannot be filled with the pass, so the pass perimeter is different from that of the pipe blank. In order to ensure the dimensional accuracy, the fillet part of the pass needs to be corrected and calculated. Therefore, this method has higher design accuracy than other methods. However, due to the large amount of iterative calculation, this method is more suitable for pass design by computer. If you use a frame that deforms both horizontally and vertically, you can directly use the deformation angle & theta; Pass design.

If the test results of square tubes fail to meet the provisions of product standards, the unqualified ones shall be selected, and double the number of samples shall be taken from the same batch of square tubes for re inspection of unqualified items. If the re inspection results (including any index required by the test of the project) are unqualified, the batch of square tubes shall not be delivered. If the following inspection items fail to pass the preliminary inspection,GreensboroGalvanized square pipe joint, re inspection is not allowed: A. There are white spots in the low magnification; b. Microscopic.Shot blasting is commonly used to clean the surface of castings or strengthen the surface of square tubes.Stage ( & mdash; )Project scope,B. tool steel: (a) carbon tool steel; (b) Alloy tool steel; (c) High speed tool steel.Spraying (throwing) derusting spraying (throwing) derusting is that the high-power motor drives the spraying (throwing) blade to rotate at high speed, so that the steel sand, steel shot iron wire section, which can not only completely remove rust, oxides and dirt, but also the square tube under the violent impact and force of abrasives, compression, bending and shear the strength is also divided into tensile strength, compressive strength, flexural strength and shear strength. There is often a certain between various strengths. Generally, tensile strength is used as the basic strength indicator. Precision pipe is a seamless pipe with high dimensional accuracy and good surface finish for mechanical structure and hydraulic equipment. The selection of precision seamless mechanical structure or hydraulic equipment can greatly save machining hours, improve material rate and improve product quality. Seamless pipe is rolled in the annular pass composed of variable cross-section circular hole groove and fixed conical plug. Cold drawing is usually carried out on single chain or double chain cold drawing machine. This method is to put the heated pipe blank in a closed cylinder, and the perforated rod and rod move to extrude the part from the smaller die hole. This method can produce steel pipe with smaller diameter.Manufacturing cost,Welding seamless welding seamless is to make welded elbows. After grinding and pickling, sand blasting, there is no sign of welding on the surface. Even using advanced flaw detection equipment, it can not be seen that they are welded elbows.Galvanized qb square pipe for low pressure fluid transmission, Standard No.: gbt-. The representative material is the same as above. It is mainly used to transport low pressure fluids such as water, gas air, oil and heating hot water or steam. The surface of square pipe adopts hot galvanizing or cold galvanizing process.During the pushing process of spot welding and repair welding elbows, there will be thinning, so manufacturers usually use thick spot pipes. If thin raw materials are used, there are about wires thinned. If the technology is not good or the drawn pipe is used, the thickness is significantly lower than the standard.Greensboro,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.Functional index analysis of qb square tube - the load on the machine parts due to the great progress of strength is called the frontal collapse load. The power of destruction of qb square tube under the frontal collapse load is called the frontal collapse toughness.Improve 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.