Huzhou special Tangshan square tube wholesale manufacturer
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.
Huzhou special Tangshan square tube wholesale manufacturer
The square tube detour is caused by improper adjustment of the rolling mill, residual stress during rolling and improper cooling along the tube section and length. Therefore, it is impossible to get very straight pipes directly from the rolling mill. Only after cold straightening the roundness of pipes can you satisfy the rules of technical conditions. The basic principle of straightening is to stop the elastic-plastic detour of the square tube from a large one to a small one, so it is necessary for the steel tube to be repeatedly detoured in the straightening machine. The level of the steel pipe's repeated detour is mainly determined by the adjustment of the straightening machine. There are many factors that affect the straightening quality, such as the roundness of the original pipe, steel pipe size and data straightening model, adjustment parameters, etc.
Huzhou special Tangshan square tube wholesale manufacturer
① The rectangular straight pipe must be manufactured on the special import assembly line to ensure the manufacturing accuracy and airtightness of the air duct. ② The blanking of rectangular air duct fittings shall be completed automatically by using computer software on the imported special machine, and the automatic plasma cutting process shall be completed on the imported special plasma cutting machine for sheet metal. ③ The seam connection of rectangular air duct shall adopt the imported automatic occluder to stop the occluding process. ④ The connection between the rectangular air duct body and the plug-in flange shall adopt the rivetless connection process, and the imported equipment shall be used to stop the rivetless connection process. ⑤ The connecting flange of rectangular air duct shall adopt the connecting process of connecting plate flange and plug-in flange. When the length of the large side of the air duct is less than or equal to 2000mm, the connecting method of common plate flange shall be adopted. When the length of the large side of the air duct is more than 2000mm and less than or equal to 2500mm, the connecting method of plug-in flange shall be adopted. The rectangular air duct shall be mechanically pressed with reinforcing bars, and the spacing between reinforcing bars shall be about 300mm.
Huzhou special Tangshan square tube wholesale manufacturer
The standards of square tubes are divided into ministerial standards and national standards. The ministerial spiral welded square tubes are divided into SY/T5037-1999 spiral welded square tubes, GB/T9711.1-1999 spiral welded square tubes GB/T9711.2-1999 and other executive standards for square tube and square tube executive standards and size tendency GB/T9711-1997 API Spec 5L SY/T5037-2000 pipe end outer diameter tendency+2.38mm - 0.79mm D<508 ± 0.75% DD ≥ 508 ± 1.00% D ± 1.25% D wall thickness tendency 50815.0% t12.5% tD ≥ 508 ＋ 17.5% t-10.5% t D<508 ± 12.5% tDC508 ± 10.0% t ± 12.5% tweld reinforcement ≤ 3.18mm 0.5-3.0mm inside ≤ 2.0mm outside ≤ 2.5mm straightness ≤ 0.2% L ≤ 0.2% L ≤ 0.25% L pipe end status bevel angle 30 ° -- 35 ° edge clipping 1.59 ± 0.79mm bevel angle ≤ 1.59mm bevel angle 30 ° -- 35 ° edge clipping 1.59 ± 0.79mm bevel angle ≤ 1.59mm bevel angle 30 ° -- 35 °
Huzhou special Tangshan square tube wholesale manufacturer
There are more and more manufacturers of seamless square and rectangular tubes. The demand and market sales are accumulated day by day, which means that the manufacture of seamless square and rectangular tubes is stopped by virtue of many advantages and characteristics of seamless square and rectangular tubes. Seamless square and rectangular tubes can be said to be icing on the cake in terms of processing technology and manufacturing process. The wear resistance and ductility of the process are relatively good. The products manufactured are smooth in appearance and superior in performance! The seamless square and rectangular tube has good strength, toughness, plasticity, welding and other process properties, and has good ductility. Its alloy layer is firmly attached to the steel base. Therefore, the seamless square and rectangular tube can stop cold punching, rolling, wire drawing bending and other forming without damaging the coating. It is suitable for ordinary processing such as drilling, cutting, welding, cold bending and other processes. The seamless rectangular tube after hot galvanizing has a bright and beautiful appearance. Seamless square and rectangular tube can be divided into seamless tube and welded tube. Seamless square and rectangular tube is extruded from seamless round tube. Generally, it can be selected and used according to detailed requirements. Due to its excellent performance, seamless rectangular tubes are widely used in such aspects as glass curtain walls, power towers, communication networks, water and gas escorts, wire casings, houses, bridges, metal structures, etc.
