Nantong special rectangular tube production
The surface of fake and inferior square tubes is often pitted. The pitted surface is the irregular concave and convex defect on the surface of the square tube caused by the serious wear of the rolling groove. Because the fake and inferior square tube manufacturers want to pursue profits, the appearance of low-quality square tubes shows pockmarks. This defect often runs through the longitudinal direction of the entire product. The reason for folding is that fake and inferior manufacturers pursue efficiency and technological transformation, and there are many impurities. The rough part of the guide equipment of the fake and inferior material manufacturer is used to investigate the reason why the appearance of the inferior square tube shows pitted surface. The excessive reduction leads to the extremely cold period. The reason why the appearance of the inferior square tube produces pitted surface is that the strength of the square tube drops greatly. The appearance of fake and inferior square tubes is easy to produce scars. There are two reasons: 1. The materials of fake and inferior square tubes are uneven, and the grooved rolling often exceeds the standard. 2. Fake square tubes are easy to fold. Folding is the cause of various broken lines formed on the surface of square tubes. The surface of low-quality square tubes shows pockmarks. The folded products will crack after bending, and fold will occur during the next rolling. These impurities are easy to produce scars after biting the rolls. The reason why the poor quality square tube appears pitted surface when the speed is reduced. Our square tubes will not appear pitted, because we will not produce inferior square tubes.
Nantong special rectangular 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.
Nantong special rectangular tube production
When designing the section of seamless square pipe, two main factors should be considered: one is the safety of the section; The other is the economy of the section. It is feasible to use elastic theory to calculate static structures, such as warehouses, houses, bridges, etc., but it is not suitable for moving components, such as wheels, etc. At this time, people often use plastic theory. The study of plasticity theory can be traced back to 1914. In 1975, the European Design Committee formulated a plastic design standard, which is mainly used for static load plane beams and frame structures subject to bending stress. Its request is as follows: for high-rise buildings, more detailed calculation is required. Under the dynamic load condition, the plastic design method usually stops the calculation of allowable stress by multiplying the allowable stress safety factor by the allowable stress which is not less than the dynamic load. When a shaft is bent, the calculation can be stopped by the formula a=Wmotion/W allowable. Using plastic method instead of elastic method to calculate strength can improve the bearing capacity of members by 14%.
Nantong special rectangular 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.
Nantong special rectangular tube production
Square and rectangular pipes can be divided into adhesive socket pipe fittings, elastic seal pattern socket pipe fittings, threaded joint pipe fittings and flange connection pipe fittings according to different connection modes. Pipe fittings can be divided into injection molding pipe fittings and pipe bending molding pipe fittings according to different processing methods. Reduction coefficient of nominal pressure and temperature Since plastic products are relatively sensitive to pressure and temperature, the nominal pressure (PN) of regular rectangular tube refers to the large working pressure when 20 C water is recommended. When the water delivery temperature is different, the working pressure shall be corrected according to the given reduction coefficient (f) for different temperatures, that is, the reduction coefficient shall be used to obtain the large allowable working pressure at the nominal pressure. The internal surface of various pipe fittings shall be lubricated and no delamination is allowed. Obvious bubbles, lines, cold spots, uneven color and other defects. For injection molded square and rectangular pipes, the wall thickness of the main body outside the socket joint shall not be less than the wall thickness of the pipe with the same specification and pressure grade: the uniform outer diameter of the pipe socket shall conform to the rules for the uniform outer diameter and deviation of the pipe in. The types and technical requirements of pipe fittings are economical. The sizes of each part of the pipe fittings are not listed. When required, product samples can be obtained from the ordering manufacturer. Adhesive socket pipe fittings. Elbows, tees, and fittings. The model drawing of the nominal outer diameter of the bonded socket elbow, tee and joint.
Nantong special rectangular tube production
Fine tube is a type of steel tube with a higher degree of fineness than steel tube, and its use is also very common. In particular, various properties and uses of fine tube are relatively important manifestations of fine tube. If fine tube is not used, it is necessary to understand the nature and use of fine tube in all aspects, so as to achieve reasonable use of fine tube. Fine tube is a special condition of steel pipe and also a good steel. It can be said that the material of fine tube is also quite special, and its application volume and market prospect are relatively large. Fine tube is a kind of high-precision steel tube material after cold drawing or hot rolling. Fine steel pipes are mainly used to consume products of pneumatic or hydraulic components, such as air cylinders or oil cylinders, which can be seamless pipes or welded pipes, because they have no oxide layer on the inner and outer walls, can accept high pressure without leakage, high precision, high brightness, cold bending without deformation, flaring, flattening without cracks, etc. The chemical composition of fine steel pipe includes carbon C, silicon Si, manganese Mn, sulfur S, phosphorus P and chromium Cr.
