Square tube structural steel A. mechanical steel: (a) quenched and tempered structural steel; (b) Surface hardening structural steel: including carburized steel, ammoniated steel and surface quenching steel; (c) Easy to cut structural steel; (d) Steel for cold plastic forming: including steel for cold stamping and steel for cold heading.The square tube is divided into a. boiling steel according to the degree of deoxidation and pouring; b. Semi killed steel; c. Killed steel; d. Special killed steel. The deformation of qb square tube is mainly caused by the shrinkage force of the weld greater than the strength of the base metal.Alajuela,Square tube with complex section: flower shaped square tube, open square tube, corrugated square tube and special-shaped square tube.For gas transmission: gas, steam and liquefied petroleum gas.Australia,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.It should be noted that the position of the disc from the calibration line can be adjusted according to the reinforcement diameter, and R and R can be equal or different.The strength, plasticity and hardness discussed above in fatigue QB are the indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.

Due to the increase of square tube production, there are more and more fake and shoddy square tubes in the market. How to distinguish the fake and shoddy square tubes? Let me teach you some points to distinguish the fake and shoddy square tubes.The square tube adopts the electric contact pressure gauge to press down the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth transportation of the strip steel.Normalized: A. pearlite steel; b. Bainitic steel; c. Martensitic steel; d. Austenitic steel.High quality and low price,It should be noted that the position of the disc from the calibration line can be adjusted according to the reinforcement diameter, and R and R can be equal or different.The pressurization size and time are the key to the success or failure of welding. If the square tube synthetic material is not pressurized, a large number of pores will be caused due to the pores of the material itself and the gas generated in the reaction. It is not allowed to leave the reactants in the weld, so it must be densified, usually pressurized during the reaction.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. Appropriate sites and warehouses shall be selected. The sites or warehouses for storing steel pipes shall be in clean and unobstructed places away from factories and mines that produce harmful gas or dust. Weeds and sundries shall be removed on the site to keep the steel pipe clean; In the warehouse, it is not allowed to stack with acid, alkali, salt, cement and other materials that are corrosive to the steel pipe. Different types of steel pipes shall be stacked separately to prevent confusion and corrosion; Large section steel rail, steel plate, large-diameter steel pipe, forging, etc. can be stacked in the open air; Small and medium-sized section steel, wire rod, reinforcement, medium diameter steel pipe, steel wire and steel wire rope can be stored in a well ventilated shed but they must be covered and padded; Some small steel pipes, steel strips, silicon steel sheets, all kinds of cold-rolled and cold drawn steel pipes and high and corrosive metal products can be stored in the warehouse; The warehouse shall be selected according to geographical conditions, and generally adopts ordinary closed warehouse, that is, the warehouse with roof, enclosure, tight doors and windows and ventilation devices; The warehouse is required to pay attention to ventilation in sunny days, close and damp proof in rainy days, and often maintain a suitable storage environment. The principle of reasonable stacking and first in first stacking is to stack according to varieties and specifications under the condition of stable stacking and ensuring safety. Materials of different varieties shall be stacked separately to prevent confusion and mutual corrosion; It is forbidden to store articles that have corrosive effect on steel pipes near the stacking position; The bottom of the stack shall be padded high, firm and flat to prevent the material from moisture or deformation; The same kind of materials shall be stacked according to the warehousing order, so as to facilitate the implementation of the principle of first in, first out; The section steel stacked in the open air must be provided with wooden mats or strip stones. The stacking surface is slightly inclined to facilitate drainage. Pay attention to the straightness of the material placement to prevent bending and deformation; The stacking height shall not exceed m for manual operation, m for mechanical operation, and m for stacking width; A fixed channel shall be reserved between stacks, generally .m, it can be padded up by .M; If it is muddy ground, it must be padded . ~ .m high. If it is an open site, the cement ground shall be padded with O & middot; ～O· m, . ~ . m higher than the sand and mud surface, the angle steel and channel steel shall be stacked in the open air, i.e. the mouth shall face down, and the I-beam shall be placed vertically. The i-groove surface of the steel pipe shall not face up to avoid ponding and rust. The packaging and protective layer of the protective materials shall be coated with agent or other plating and packaging before leaving the factory, which is an important measure to prevent material corrosion. Attention shall be paid to protection during transportation, loading and unloading and shall not be damaged The storage period of materials can be extended, the warehouse shall be kept clean and the maintenance of materials shall be strengthened. Before warehousing, materials shall be prevented from being drenched or mixed with impurities. Materials that have been drenched or contaminated shall be wiped according to their properties, such as steel wire brush for high hardness and cloth, cotton and other materials for low hardness; The materials shall be regularly after warehousing. If there is corrosion, the corrosion layer shall be removed; Generally, the steel pipe surface does not need to be coated with oil after being cleaned, but for high-quality steel, thin-walled pipe, alloy steel pipe, etc., the internal and external surfaces need to be coated with anti rust oil before storage; Steel pipes with serious corrosion shall not be kept for a long time after rust removal and shall be used as soon as possible. With the development of economy, all kinds of square tubes, rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes have been recognized by the majority of customers for a long time. There are more and more counterfeit products on the market. In order to prevent being deceived when you are in square tubes, you need to know some knowledge about how to judge the authenticity of square tubes: & ldquo; We can judge by observing the surface and flatness of the square tube. If the surface of the square tube is relatively flat, it can reflect that the square tube is good. On the contrary,AlajuelaGanzhou galvanized pipe, if the surface is not good

Mechanical engineering, power plants, agricultural and chemical machinery, glass curtain walls, airports, boiler construction, highway railings, housing construction, pressure vessels, oil storage tanks, bridges, heavy transportation machinery and other welded structural parts with high load, etc. Process classification: according to the production process, square tubes are divided into hot-rolled seamless square tubes, cold drawn seamless square tubes, seamless square tubes and qb square tubes.Honest management,Hardness 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.Square tube flattening test is a kind of test to check the deformation performance of metal tubes (seamless square tubes and rectangular tubes) flattened to the specified size and show their defects. Relevant flattening tests shall be carried out in accordance with relevant provisions of test standards. Requirements for samples samples can be taken from metal pipes with qualified appearance. Generally, sawing is adopted. The inner and outer walls of the pipe shall retain the original surface without any processing. Sample length L & asymp; D (D is the outer diameter of the pipe). When the outer diameter is large, the length l shall not exceed mm. When the outer diameter is less than mm, l = mm. When cutting the sample, the surface of the sample shall not be damaged and the performance of the metal shall not be changed due to heating or cold processing. The edge of the section shall be flattened. The flattening test is a test to check the deformation performance of the metal pipe (seamless square pipe and rectangular pipe) flattened to the specified size and show its defects. Relevant flattening tests shall be carried out in accordance with relevant provisions of test standards.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,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,AlajuelaSquare galvanized square pipe, 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.For oil the oil brush work shall be carried out in accordance with the requirements of the rule system, so as to ensure the oil brush and the oil in the correct position of the brush and avoid wrinkles.The reason why the surface of fake and shoddy materials is easy to crack is that its blank is adobe with many air holes. During the cooling process, the adobe has cracks due to the action of thermal stress, and there are cracks after rolling.