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The inspection items sampling quantity, sampling position and test of square tube shall be in accordance with the provisions of corresponding product standards. With the consent of the demander, hot-rolled square tubes can be sampled in batches according to the rolled root array.If the re inspection results are unqualified (including the items whose preliminary inspection results are unqualified and re inspection is not allowed),GuaimakaQ235A galvanized pipe, 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.Guaimaka,× × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × Standard treatment of steps for preventing oxidation of ~ square tube square tube is a kind of metallic maintenance. The main components are iron and zinc. It is easy to have redox reaction in the air. Once the reaction occurs, many new substances have taken place, and the original characteristics have changed. However, in order to maintain the original relevant characteristics, which is the way to isolate the oxygen in the air. Today, this article makes a relatively standardized treatment on the relevant steps to prevent oxidation of square tubes: the key depends on what kind of antirust paint you use. . If you use epoxy zinc rich or iron rich antirust paint, you can directly spray fluorocarbon paint on it; if alkyd antirust or red lead is used, it shall be cleaned with paint remover and sprayed with epoxy zinc rich or iron rich antirust paint again before fluorocarbon paint can be sprayed.Ship carbon steel square pipe (gb-) is a carbon steel square pipe for ship class I pressure pipe system, class II pressure pipe system, boiler and superheater. It is a long-term business square pipe, square pipe, seamless square pipe, and the working temperature of alloy steel square pipe wall shall exceed ℃.Gambela,Principle of cold drawing strengthening: the lattice defects of steel increase during plastic deformation,GuaimakaThick wall galvanized square pipe manufacturer, and the serious distortion of defect lattice will hinder the progress and slip of lattice, 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.The other is designed with deformation angle, which can be regarded as DEG from round tube to square tube; To & deg; The bending deformation of angle, so the deformation angle & theta; It can accurately reflect the deformation degree of corners and edges. In the design process, considering the influence of dimensional accuracy and metal work hardening, the distribution of deformation angle is usually larger at the beginning and middle passes, and then gradually decreases. In the pass formed directly by arc intersection, the fillet part of the pipe blank cannot be filled with the pass, so the pass perimeter is different from that of the pipe blank. In order to ensure the dimensional accuracy, the fillet part of the pass needs to be corrected and calculated. Therefore, this method has higher design accuracy than other methods. However, due to the large amount of iterative calculation, this method is more suitable for pass design by computer. If you use a frame that deforms both horizontally and vertically, you can directly use the deformation angle & theta; Pass design.The local heat release in the welding process of square tube can reduce the heat affected zone, avoid the micro of thermal sensitive materials, and maintain the properties of materials.

Comprehensive classification ordinary steel A. carbon structural steel: (a) Q (b) Q (b); (c) Q( C)； (d) Q( B)； (e) Q.Ordinary carbon steel is divided into Q Q q SS, # steel, # steel, etc.The local heat release in the welding process of square tube can reduce the heat affected zone, avoid the micro of thermal sensitive materials, and maintain the properties of materials.Test method,Square tube production most square tube processing is square tube pressure processing, resulting in plastic deformation of the processed steel (billet, 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.The second is the pickling of the square pipe. Both chemical and electrolytic methods are used when pickling the square pipe. These two methods can remove the oxide skin of the square pipe.The disadvantage of empty bending is that when the upper side and side are synchronously empty bending, the forming force is easy to exceed the critical point due to the pressure generated by the upper roll and the lower roll at the same time, resulting in edge instability and concave and will also affect the stable operation and forming quality of the unit. This is also the different characteristics of qb square tube and round tube empty bending. The concept of square tube: square tube is the pressure processing of ingot, billet or square tube Make materials of all shapes, sizes and properties we need.

B. tool steel: (a) carbon tool steel; (b) Alloy tool steel; (c) High speed tool steel.Word of mouth recommendation,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, but steel is not completely equal to ferrous metal.Galvanized qb square pipe for low pressure fluid transmission, Standard No.: gbt-. The representative material is the same as above. It is mainly used to transport low pressure fluids such as water, gas, oil and heating hot water or steam. The surface of square pipe adopts hot galvanizing or cold galvanizing process.Stage ( & mdash; )Guaimaka,C. special performance steel: (a) stainless and acid resistant steel; (b) Heat resistant steel; (c) Electric heating alloy steel; (d) Electrical steel; (e) High manganese wear resistant steel.Structural stainless steel square pipe (gbt-) is a hot-rolled (extruded, expanded) and cold drawn (rolled) square pipe made of stainless steel for corrosion-resistant pipes structural parts and parts widely used in chemical, petroleum, light textile, food, machinery and other industries.Steel used & mdash& mdash; Such as bridge steel, ship steel, boiler steel, pressure vessel steel, agricultural machinery steel, etc.