The appearance of fake and inferior square tubes often has pitting. Pockmarked surface is an irregular uneven defect on the surface of square lead pipe due to serious wear of rolling groove. Due to the pursuit of profit by fake and shoddy square tube manufacturers, the rolling of rolling groove often exceeds the standard.Large diameter qb square tube production standard classification square tube is divided according to production standard: national standard square tube, Japanese standard square tube, British standard square tube,deathSquare tube galvanizing company, American standard square tube, European standard square tube and non-standard square tube.death,The qb square tube rolled from the strip steel through process treatment is generally to unpack, flatten curl and weld the strip steel to form a round tube, then roll the round tube into a square tube, and then cut it to the required length. Nowadays, the forming of qb square tube has solid bending and empty bending. The bending degree of qb square tube shall not be greater than mm per meter, and the total bending degree shall not be greater than the actual bending of the total length. As the name suggests, the bending is compacted, and the internal and external rollers and the internal and external walls of the tube blank are compacted in both directions during the actual bending.The square tube for fluid transportation (gbt-) is a general square tube for transporting water, oil, gas and other fluids.Shirbin,B. converter steel: (a) acid converter steel; (b) Basic converter steel. Or (a) bottom blown converter steel; (b) Side blown converter steel; (c) Top blown converter steel.Among them qb square tube is divided into: (a) by process & mdash& mdash; Arc welded square pipe, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Straight seam welded square pipe, spiral weldingFerroalloy is an alloy composed of iron and silicon, manganese, chromium, titanium and other elements. Ferroalloy is the raw material for steelmaking. It is used as deoxidizer and alloy element additive for steel in square tube steelmaking.

The surface of fake and inferior square tubes is easy to produce scabs. There are two reasons: the material of fake and inferior square tubes is uneven and there are many impurities. The guide equipment of fake and shoddy material manufacturers is simple and easy to stick to steel. These impurities are easy to scar after biting the roll.Upper yield point (& sigma; Su): the large stress before the yield of the sample occurs and the stress decreases for the first time; Lower yield point (& sigma; SL): the small stress in the yield stage when the initial instantaneous effect is not considered.Stage ( & mdash; )Which one is better,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, 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.Improve the positioning and pre bending steps, if necessary, to ensure that the web hunting problem does not occur when pressing parts. Change the shape of the surface pressure of the material to ensure the quality of the parts and avoid the non movement of the surface shape of the roll gap, resulting in uneven walking feeding.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, phosphorus, mainly including the following: square tubes are classified into ordinary steel according to quality (P & le; .%, S & le; .%)

In the square tube production process of welding before forming, the forming is mainly completed by the sizing frame. The sizing machine is generally a two high mill, including horizontal frame and vertical roll frame. At present, there are mainly two kinds of square pipe pass design: one is the horizontal frame is designed according to the box hole, the frame is an elliptical hole, and the other frames are approximately rectangular holes. The pass section is composed of circular arc. Professional projects include: square pipe square pipe, seamless square pipe, galvanized square pipe, galvanized pipe and other related businesses. Please welcome merchants who want to have this business. And the arc radius increases frame by frame, The fillet radius of the joint between the side wall and the bottom of all pass patterns is equal to the fillet radius of the finished section. The total elongation coefficient of the square tube is about , which is mainly distributed on the flat roller. The deformation of the vertical roller is very small, and its function is to press down the short side of the square tube. With this design, the calculation is complex and the calculation value is not accurate enough. It is necessary to constantly correct the pass circumference.Inspection basis,The pipeline is only subject to chemical pickling, which can remove oxide scale, rust and old coating. Sometimes it can be used as the reprocessing after sand blasting. Although chemical cleaning can make the surface reach a certain cleanliness and roughness, its anchor lines are shallow and easy to pollute the surrounding environment. The square tube shall be submitted for acceptance in batches,deathGalvanized pipe manufacturer, and the batch rules shall comply with the provisions of corresponding product standards.The new improvement ensures that square tubes can be used for a long time. With the development of the times, square tubes are used in more and more fields. So how can we correctly choose square tubes? Next, I'll introduce the process of lower tubes.For oil, the oil brush work shall be carried out in accordance with the requirements of the rule system,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,deathSquare tube factory, 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.Spraying (throwing) derusting spraying (throwing) derusting is that the high-power motor drives the spraying (throwing) blade to rotate at high speed, so that the steel sand, steel shot, iron wire section, minerals and other abrasives can be sprayed (thrown) on the surface of the square tube under the action of centrifugal force, which can not only completely remove rust, but also the square tube under the violent impact and force of abrasives, It can also achieve the required uniform roughness.When storing QB square pipe, we need to select a suitable place. We need to think about many external factors, such as the corrosivity of steel pipe, etc. Therefore, the place must be clean, dry and ventilated, where harmful gases appear, QB square pipe can not appear, and the outer surface of steel should be kept clean. If there are acid, alkali, salt, etc. in the warehouse, so try to cut it and don't let it. In addition, if we can think about those higher metal products, we can put them into the warehouse for very good retention. According to geographical conditions, there is a sealed warehouse, but the ventilation setting is excellent. The difference between QB square tube and seamless steel tube QB square tube is a kind of high-precision steel tube material after cold drawing or hot rolling treatment. QB square tube is mainly used to produce products of pneumatic or hydraulic components such as air cylinder or oil cylinder, which can be seamless pipe or welded pipe, because there is no oxide layer on the inner and outer walls of QB square tube, no deformation under high pressure, high precision, high finish, cold bending flaring and flattening without cracks. The chemical composition of QB square tube includes carbon silicon Si, manganese Mn, sulfur s, phosphorus P and chromium CR.