Classification of square tube steel is iron carbon alloy with carbon content of square tube between .% - %. In order to ensure its toughness and plasticity, the carbon content generally does not exceed %. In addition to iron and carbon, the main elements of steel also include silicon, manganese, sulfur, phosphorus, etc. There are various classifications of steel and square tubes mainly including the following: square tubes are classified into ordinary steel according to quality (P & le; .%,PansosGalvanized pipe connector, S & le; .%)Square tube production most square tube processing is square tube pressure processing, resulting in plastic deformation of the processed steel (billet, ingot, etc.). According to the square tube processing temperature, the square tube can be divided into cold processing and hot processing. The main processing of square tube includes: rolling: the gap (various shapes) between the square tube metal blank and the rotating roll , because of the compression of the roll, the material section is reduced and the length is increased. This is a common production method for producing square tubes. It is mainly used to produce square tube profiles, plates and tubes. It is divided into cold rolling and hot rolling.Pansos,The quality of the solid square tube after the square tube formwork removal and curing can be tested according to the requirements and the following ways: use a magnifying glass to observe whether there are non external force cracks on the structural surface of the solid seamless qb square tube. When non external force cracks appear on the surface of qb square pipe, the crack width on the structural surface of ordinary qb square pipe shall not be greater than .mm.With the progress of the times and the faster and faster economic development,PansosGalvanized square pipe and rectangular pipe, the places where large-diameter seamless square tubes are used are becoming more and more popularSaint-Louis,Principle of cold drawing strengthening: the lattice defects of steel increase during plastic deformation, and the serious distortion of defect lattice will hinder the progress and slip of lattice, the modulus of steel decreases. The cold drawn reinforcement is stored at room temperature for ~ d or heated to ~ ℃ and maintained for a fixed time. This process is called aging treatment.The advantage of empty bending is that it can bend the side length when the real bending cannot be carried out, such as synchronous bending and finishing of the upper side and side of qb square tube. Empty bend can also bend R & amp; amp; lt; .T without fracture of pipe wall.Strength QB square strength refers to the performance of metal materials under static load (excessive plastic deformation or fracture). Since the action modes of load include tension, 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.

If there is only a single plane weld, that is, the arc of the section weld shall be terminated at the section arc.At present, researchers at home and abroad have carried out experimental discussion on the anti adhesion of square tube surface. So far, there is still a lack of research on surface adhesion there is no systematic and perfect theory to guide the preparation of anti adhesion inner surface of pipeline, and there is a lack of operable and low-cost inner surface preparation technology of square pipe. In terms of solid surface adhesion mechanism, based on the solid-liquid interface adhesion work theory and smooth solid surface model, this paper analyzes the spreading process on machined rough surface, studies the dynamic movement characteristics of solid-liquid vapor phase line, directly analyzes the adhesion process, and establishes a line spreading model based on small system energy, It provides theoretical guidance for the preparation of anti adhesion surface of pipeline.According to metallographic classification, the annealed state of square tube: A. hypoeutectoid steel (ferrite + pearlite); b. Eutectoid steel (pearlite); c. Steel precipitation through a common square tube (pearlite + cementite); d. Ledeburite steel (pearlite + cementite).Customer first,Section shape classification square tubes are classified according to section shape: simple section square tubes & mdash& mdash; Square tube,PansosHow much is a galvanized square tube, rectangular tube and complex section square tube & mdash& mdash; Surface treatment classification of flower shaped square pipe open square pipe, corrugated square pipe and special-shaped square pipe square pipe is divided into hot-dip galvanized square pipe, electro galvanized square pipe, oil coated square pipe and pickling square pipe according to surface treatment. Square pipe is classified according to purpose & mdash& mdash; Square tubes for decoration machine tools and equipment, chemical industry machinery industry, steel structure, shipbuilding, automobile, steel beam and column and special purpose are classified by wall thickness & mdash& mdash; Super square tube, square tube and thin-walled square tube plasticity refers to the ability of metal materials to produce plastic deformation (deformation) without deformation under load.The strength, plasticity and angle discussed later are the machine function indicators of metal under static load. In practice, many mechanical machines are under repeated load, and the whole opportunity is tired in this environment.Functional index analysis of qb square tube - commonly used are Brinell angle (HB),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.High strength structural steel with carbon content of .% - .%, adding main alloy elements such as manganese, silicon, vanadium, niobium and titanium; Its total alloy content is %. According to the strength, it is divided into four levels: , , and MPa.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.Pansos,If there is only a single plane weld, the step-by-step back welding shall be adopted from the middle, that is, the arc of the section weld shall be terminated at the section arc.Welding is a synthetic gradient material, mechanical and physical properties between base metals.Principle of cold drawing strengthening: the lattice defects of steel increase during plastic deformation, so the yield point of steel increases and the plasticity and toughness decrease. Due to the internal stress in plastic deformation, the modulus of steel decreases. The cold drawn reinforcement is stored at room temperature for ~ d or heated to ~ ℃ and maintained for a fixed time. This process is called aging treatment.