Wuxi medium thick wall square tube production
1. The straight square passes can be divided into two categories: one is the special pass, that is, fixed body making. The forming methods of this method include: fixed point reducing method, variable point sizing method, fixed diameter bending point outward moving method, fixed diameter bending point inward and outward moving method. The second type is the general pass, which is currently used by most domestic consumer enterprises. General pass is the third and fourth combination of special pass forming methods. In this pass, the upper roll at the bend has a fixed fillet, and different strip thicknesses are treated with the same upper roll. In practice, a vague technology is used to solve the problem. This technology saves a lot of rolls, so most consumer manufacturers want to use this pass. 2. There are roughly two forming methods of round to square: first, box pass deformation. Box pass deformation is that the main pipe stops deformation on the main pipe after the alternate action of four ordinary flat rolls and three vertical rolls or more passes of flat rolls and vertical rolls. It can be simply described as: flat roll up and down extrusion is referred to as "flattening"; vertical roll left and right extrusion is referred to as "extruding". The main pipe gradually approaches the profile shape in several processes of "flattening" and "extruding", and then becomes the required profile. Second, four roll deformation. Four roll deformation means that four rolls form a pass in the same plane, and the main pipe passes through the pass, similar to drawing deformation, but it changes the drawing fixed die into a separate rolling die.
Wuxi medium thick wall square tube production
Square alloy tube with ferrite structure in service. Chromium content is 11%~30%, with body centered cubic crystal structure. This kind of steel generally does not contain nickel, and sometimes contains a small amount of elements such as Mo, Ti, Nb, etc. This kind of steel has the characteristics of high thermal conductivity, small shrinkage coefficient, good oxidation resistance, stress corrosion resistance, etc. It is mostly used to manufacture parts and components resistant to atmospheric, steam, water and oxidizing acid corrosion. The application of this kind of alloy square tube is limited because of its poor plasticity, significantly reduced plasticity and corrosion resistance after welding. The application of secondary refining technology (AOD or VOD) can greatly reduce the interstitial elements such as carbon and nitrogen, thus making this kind of steel widely used.
Wuxi medium thick wall square tube production
The construction process of square tube is relatively simple. If the square tube consumer manufacturer needs to add another process after using the round tube for construction, that is to change the cross section of the round tube to square, and the cross section of the square tube is square originally, so this process can be omitted, and the construction will be easier to stop. Analysis of seismic resistance and bearing capacity of square tube. After repeated experiments on square tubes and round tubes by square tube consumer manufacturers, it is found that square tubes can accept greater pressure and vibration than round tubes, which illustrates that the use of square tubes can improve the quality of buildings, so it is natural to choose square tubes.
Wuxi medium thick wall square tube production
Rectangular tube is a kind of light thin-walled steel tube with hollow square section, also known as steel cold-formed section. It is a shape steel with square section and overall dimension made of Q235 hot-rolled or cold-rolled strip or coil as the base material after cold bending and forming and then high-frequency welding. Hot rolled extra thick wall square tubes, except for the thickening of wall thickness, have corner dimensions and edge straightness to the extent that they exceed the resistance welded cold formed square tubes.
Wuxi medium thick wall square tube production
In the process of bending, the tightening of the square tube moment produces bending deformation, while the internal and external square and rectangular tubes, the inner wall of the two-way real pressure state roll, however, must be based on professionals. The main advantage of real bending is relatively small rebound, and it is very accurate when forming. In the data of its roll shape, ordinary internal angle forming and more accurate. However, these two methods have one defect, that is, the bending of rectangular tubes is always true, which can stretch and reduce the length and thickness of ordinary stretching. However, in the process of empty bending, it is the compressed line of the bent rectangular tube, and the length of the bent line will be lengthened after it is generated, which will produce thickening effect with empty bending. The advantage of this method is that no wall damage will occur no matter the internal angle is smaller than R bending. The defect is that the forming force will exceed the load due to the upward and downward pressure at the same time, and will affect the use of tube length. However, in the application of theory, we should try our best to arrange as soon as possible, and choose the right place and correct operation in the construction process.
Wuxi medium thick wall square tube production
Square tubes are divided into plain carbon steel square tubes and low-alloy square tubes according to their materials. 1. Ordinary carbon steel is divided into Q195, Q215, Q235, SS400, 20 # steel, 45 # steel, etc. 2. Low alloy steels include Q345, 16Mn, Q390, ST52-3, etc. According to consumption specifications, the square tube can be divided into: 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 tubes are classified according to the section shape: 1. Simple section square tubes: square square tubes, rectangular square tubes. 2. Complex cross-section square tube: flower shaped square tube, tooth shaped square tube, corrugated square tube, special-shaped square tube. Square tubes are divided into hot-dip galvanized square tubes, electrogalvanized square tubes, oiled square tubes and pickled square tubes according to their appearance. Square pipes are classified according to their uses: square pipes for decoration, machine tool equipment, machinery industry, chemical industry, steel structure, shipbuilding, automobile, steel beam and column, and special pipes. Square and rectangular tubes are classified according to wall thickness: extra thick square and rectangular tubes, thick square and rectangular tubes and thin-walled square and rectangular tubes.
