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).Ostankako
category：Building materials / date：2023-03-13 10:43:36 / browse：74 / comment：5
The principle is similar to that of the plate rolling machine. The bending machine can determine a circle. Adjust the height to adjust the curvature.According to metallographic classification,Preheating must be carried out before heat treatment of qb square tube, so as to better ensure that there will be no many problems in the whole heat treatment process of qb square tube, and the quality of qb square tube will also be well guaranteed.The difference between hot-dip galvanized square pipe and cold-dip galvanized square pipe is mainly from the following aspects: the appearance of hot-dip galvanized square pipe is slightly rough compared with cold-dip galvanized square pipe; The appearance of cold galvanized square pipe is smooth and bright.Balatah, 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.Generally speaking, square pipe welding has a process: ignition, pressurization and thermal insulation.There are many ways of ignition, electric spark, flame, strong current, high-temperature furnace, electron beam,OstankakoGalvanized square pipe hot-dip galvanized square pipe,OstankakoPrice of galvanized round pipe, high-temperature radiation, microwave, chemical furnace,OstankakoSpecification and price list of galvanized iron square pipe, etc.
Steel for construction and engineering according to the classification of use without phase transformation or partial phase transformation of square tube: A. ordinary carbon structural steel; b. Low alloy structural steel; c. Steel reinforcement.Elongation after square tube breaking (& sigma;): in the tensile test, the percentage of the length increased by the gauge length of the sample after breaking and the length of the original gauge length is called elongation. In & sigma; Expressed in%.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.superior quality,A. 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.Empty bending empty bending is the bending moment formed in one direction between the outer roll and the outer wall of the tube blank to bend the strip. Empty bending will compress the bending line, the compression effect will lengthen the bending line longitudinally, and the metal at the bending will accumulate and thicken, which is the compression thickening effect of empty bending. special shaped square pipe is the general name of square pipes with other cross-section shapes except circular pipe. According to the different cross-section shape and size of steel pipe, it can be divided into special-shaped square pipe with equal wall thickness (code D), special-shaped square pipe with unequal wall thickness (code BD) and special-shaped seamless steel pipe with variable diameter (code D) These special-shaped large-diameter qb square tubes are widely used in various structural parts tools and mechanical parts. Compared with circular tubes, special-shaped tubes generally have large moment of inertia and section modulus, and have large bending and torsion resistance, which can greatly reduce the structural weight and save steel. Square tubes are an indispensable part of construction work
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.Excellent service,Derusting: This is an important process for galvanized square pipes and components before coating, in order to make the front end of the square tube pass through the die hole smoothly, so that the clamp jaw of the drawing trolley can the head of the square tube, it is necessary to sharpen the head of the square tube before drawing. Therefore, the end of the square tube with a fixed length should be heated in the slit heating furnace, It is generally ~ mm, and the heating temperature is between ~ ℃ according to different wall thickness. Then use ~ kg air hammer to sharpen and grind the head of the square pipe. Generally, the square pipe with diameter less than mm can be sharpened by rotary forging hammer or roll forging machine.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.Ostankako,Section shape classification of large-diameter qb square tube square tube is classified according to section shape: simple section square tube & mdash& mdash; Square tube, rectangular tube and complex section square tube & mdash& mdash; Flower shaped square pipe, open square pipe, corrugated square pipe, special-shaped square pipe, large-diameter qb square pipe surface treatment classification square pipe is divided according to surface treatment: hot-dip galvanized square pipe, electro galvanized square pipe, oil coated square pipe, acid pickling square pipe, large-diameter qb square pipe purpose classification square pipe is classified according to purpose & mdash& mdash; Square tubes for decoration, machine tool equipment, machinery industry, chemical industry, steel structure, shipbuilding, automobile, steel beam and column, special purpose, large-diameter qb square tube wall thickness classification, large-diameter qb square tube according to wall thickness Classification & mdash& mdash; Super large diameter qb square pipe, large diameter qb square pipe and thin-wall large diameter qb square pipe rectangular pipe are the names of square pipe and QB square pipe, that is, steel pipe with equal side length. It is made of rolled strip steel after process treatment. Generally, the strip steel is unpacked, leveled, crimped and welded to form a round pipe, then rolled into a square pipe from the round pipe, also known as square and rectangular cold-formed hollow section steel, is referred to as square pipe and rectangular pipe, code f and j respectively. The allowable deviation of wall thickness of qb square pipe shall not exceed plus or minus % of nominal wall thickness when the wall thickness is not greater than mm, plus or minus % of wall thickness when the wall thickness is greater than mm, except for the wall thickness of corner and welding joint area.Square tube for automobile half shaft sleeve (gb-) is a high-quality carbon structural steel and alloy structural steel hot-rolled square tube for automobile half shaft sleeve and drive axle housing.Main uses of square tube: square tube is mainly used in tap water engineering petrochemical industry, chemical industry, electric power industry, agricultural irrigation and urban construction. It is one of the key products developed.
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