The disadvantage of empty bending is that during synchronous empty bending at the upper and side, due to the pressure generated by the upper roll and the lower roll at the same time, the forming force is easy to exceed the critical point. All kinds of square tubes, square rectangular tubes, seamless square tubes galvanized square tubes and galvanized tubes have formal qualifications. Welcome to telephone inquiry and sincerely invite cooperation! It will cause edge instability and concave, and will also affect the stable operation of the unit and forming quality. This is also the different characteristics of qb square tube and round tube empty bending.Put the pig iron for steelmaking into the steelmaking furnace according to the specified process to obtain steel. The products of steel include ingots, continuous casting billets and various steel castings made of straight square tubes. Generally speaking, steel refers to the steel rolled into various square tubes. Square tube steel belongs to ferrous metal,The painting of the square tube has to go through a process, which requires us to conduct comprehensive consideration and analysis. In particular, the quality and level of the paint and the relevant technical level deserve our attention. Note that the square tube should not be used immediately after painting, but should be placed for a period of time and wait until the paint is dry!Compared with other welding, square pipe welding has many advantages, mainly because of the exothermic reaction, the material only needs to be heated below the melting pointDhi Sufal,We all know very well. Therefore, the quality of square tubes will directly affect the development of the construction industry. What if we can make the service life of square tubes longer? Here, we also need to ask the personnel of the square tube manufacturer for instructions, and use ingenious methods to prolong the service life of the square tube, so that the square tube can bring us greater help in life.Solution treatment and nondestructive testing sand rolling treatment and sand blasting treatment many manufacturers in the market do not do solution treatment and % penetration nondestructive testing, and many of them use sand blasting instead of sand rolling. After these steps are omitted,SalfeldenGalvanized square tube thin wall, the cost is greatly reduced.Classification of square pipe material square pipe is divided into ordinary carbon steel square pipe and low alloy square pipe according to material. Ordinary carbon steel is divided into Q Q q SS, # steel, # steel, etc; Low alloy steels are divided into q Mn, Q, St-, etc.

If the re inspection results are unqualified (including the items whose preliminary inspection results are unqualified and re inspection is not allowed), the supplier can submit them for acceptance one by one; Or re conduct heat treatment (the number of RE heat treatment shall not exceed times), and propose acceptance with a new batch.Section shape classification square tube is classified according to section shape: simple section square tube: square tube, rectangular square tube.Generally speaking, square pipe welding has a process: ignition, pressurization and thermal insulation.technological innovation,Precision inner diameter square tubes for hydraulic and pneumatic cylinders (gb-) are cold drawn or cold-rolled precision square tubes with precision inner diameter for hydraulic and pneumatic cylinders.Square tubes for low and medium pressure boilers (gb-) are high-quality carbon structural steel hot-rolled and cold drawn (rolled) square tubes for superheated steam tubes,SalfeldenGalvanized square pipe plastic spraying, boiling water tubes for low and medium pressure boilers of various structures and superheated steam tubes, large smoke tubes, small smoke tubes and arch brick tubes for locomotive boilers. Square tubes for high-pressure boilers (gb- is a high-quality carbon steel, alloy steel and stainless heat-resistant steel square tube for the heating surface of water tube boilers with high pressure and above. High pressure square tube for chemical fertilizer equipment (GB - is a high-quality carbon structural steel and alloy steel square tube suitable for chemical equipment and pipelines with working temperature of - ~ ℃ and working pressure of ~ mA.Fatigue strength, plasticity and hardness discussed above are indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.

B. low alloy structural steel C. ordinary structural steel and high-quality steel for specific purposes (including high-quality steel)device management,After chemical pickling, the square tube can be well protected by electrolysis. These are simple ways to prolong the service life of the square tube, We only need to treat according to these, so that the square tube can bring us great help in the use process. The cold galvanized square tube is the principle of cold galvanizing on the square tube used to make the square tube have corrosion performance. Different from hot-dip galvanizing, cold galvanizing coating is mainly carried out according to the electrochemical principle. Therefore it is necessary to ensure the sufficient of zinc powder and steel, resulting in electrode potential difference, so the steel surface treatment requirements are very high.General square pipes are stacked outdoors, and most of them are buried underground when in use, so they are easy to corrode and rust. In order to ensure the smooth flow of the pipeline, it will cause oil and gas leakage, which will not only interrupt transportation, and may even lead to fire and cause harm.It is good to purchase Baosteel's materials for cold drawing of square tubes, because Baosteel's materials are subject to grade flaw detection and the density of steel is relatively good. After cold drawing and heating, it is convenient to line up. The steel is cold drawn at room temperature to produce plastic deformation, so as to improve the yield strength. This process is called cold drawing strengthening. Square tube is generally used for product parts with high requirements. It has good willfulness and strength. The surface is better after cold drawing. Cold drawing principle.Salfelden,Change to square pipe: generally,SalfeldenGalvanized pipe DN300, the strip steel is unpacked, leveled crimped and welded to form a round pipe, and then cut into the required length. Stage ( & mdash; )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 popularA. 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.