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).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.Saint Lucia Milpas Alta, Standard No.: gbt-. The representative material is Q grade B steel, drainage and vertical shaft gas drainage straight seam qb square pipe.Square tubes are classified by forming: forged steel; Cast steel; Hot rolled steel; Cold drawn steel.KishiIn this period, the technology of continuous rolling pipe was not mature.Square tube has a wide range of application fields. Its main field is the construction industry, which promotes the development of economic construction. Because the production process of square tube hole is different, the production design of square tube hole is also different. Next, I will introduce in detail the types of tube hole design below.B. tool steel: (a) carbon tool steel; (b) Alloy tool steel; (c) High speed tool steel.

The disadvantage of solid bending is that it has tensile thinning effect. The actual bending will produce tension at the bending point, and the tensile effect will shorten the longitudinal length of the bending line; The metal at the real bend will become thinner due to stretching.Square tube has good machinability, good cold deformation plasticity and weldability; In addition, the toughness of steel does not decrease much during heat treatment but it has quite high strength and wear resistance, especially when water quenching; However, this steel has great resistance to white spots, temper brittleness and overheating during heat treatment.With the improvement of production quality, the quality of square tubes is getting better and better. The quality of square tubes will affect our lives. Because the functions of square tubes are different, their characteristics and uses are different. I will introduce the characteristics and uses of square tubes in detail.Total quality assurance,The square tube for fluid transportation (gbt-) is a general square tube for transporting water, oil, gas and other fluids.If the test results of square tubes fail to meet the provisions of product standards, the unqualified ones shall be selected, and double the number of samples shall be taken from the same batch of square tubes for re inspection of unqualified items. If the re inspection results (including any index required by the test of the project) are unqualified, the batch of square tubes shall not be delivered. If the following inspection items fail to pass the preliminary inspection, re inspection is not allowed: A. There are white spots in the low magnification; b. Microscopic.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.

Square tube is a very good steel in economic construction. There are many kinds and principles of cold drawing. You may still have a lot of insufficient understanding of the cold drawing principle of each other's pipe. Next, I'll lead you to learn its cold drawing principle.Product range,After spraying (throwing) derusting, it can not only expand the physical adsorption on the pipe surface,Saint Lucia Milpas AltaCold galvanized steel pipe, but also enhance the mechanical adhesion between the layer and the pipe surface. Therefore, spray (throwing) derusting is an ideal derusting method for pipelines. Generally speaking, shot blasting (sand) is mainly used for the inner surface treatment of the pipe, and shot blasting (sand) is mainly used for the outer surface treatment of the pipe. Several problems should be paid attention to in derusting by spraying (throwing).In case of doubt about the strength of solid qb square tube, the core drilling sampling method can be used for verification.Among them and the measured average strength is required to be not lower than the design value or the specified value. When the requirements are not met, 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 weldingSaint Lucia Milpas Alta,The local heat release in the welding process of square tube can reduce the heat affected zone,Saint Lucia Milpas AltaGeneral distribution of galvanized square pipe, avoid the micro of thermal sensitive materials, and maintain the properties of materials.In the square tube production process of welding before forming,Saint Lucia Milpas AltaHow much is 30 galvanized square tube, 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.Hardness QB square hardness is a pointer to measure the hardness and softness of metal materials. At present, the hardness method is commonly used to measure the hardness in production. It uses the indenter with fixed geometry to measure the hardness value of the metal material surface tested under fixed load according to the degree of hardness.