Brinell hardness (HB), Rockwell hardness (HRC) and Vickers hardness (HV) are commonly used.The disadvantage of empty bending is that during synchronous empty bending at the upper and side due to the pressure generated by the upper roll and the lower roll at the same time, the forming force is easy to exceed the critical point. All kinds of square tubes, square rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes have formal qualifications. Welcome to telephone inquiry and sincerely invite cooperation! It will cause edge instability and concave and will also affect the stable operation of the unit and forming quality. This is also the different characteristics of qb square tube and round tube empty bending.Antigo kuscatland,The quality of the solid square tube after the square tube formwork removal and curing can be tested according to the requirements and the following ways: use a magnifying glass to observe whether there are non external force cracks on the structural surface of the solid seamless qb square tube. When non external force cracks appear on the surface of qb square pipe, the crack width on the structural surface of ordinary qb square pipe shall not be greater than .mm.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.Tulkarm,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 advantage of empty bending is that it can bend the side length when the real bending cannot be carried out, such as synchronous bending and finishing of the upper side and side of qb square tube. Empty bend can also bend R & amp; amp; lt; .T without fracture of pipe wall.After cold drawing and aging treatment, the yield point is improved, the tensile ultimate strength is also increased, and the plasticity continues to decrease. Due to the reduction of internal stress during aging, the modulus can be basically restored. According to this principle, cold drawing or cold drawing of reinforcement or low carbon steel wire rod is often carried out on site or prefabricated component factory, so as to improve yield strength and save steel.

After cold drawing and aging treatment, the yield point is improved,Antigo kuscatlandQ235 galvanized square pipe, the tensile ultimate strength is also increased, the modulus can be basically restored. According to this principle, cold drawing or cold drawing of reinforcement or low carbon steel wire rod is often carried out on site or prefabricated component factory, so as to improve yield strength and save steel.For seamless qb square tubes, there is a certain hardness, so there are still many for bearing in application, so it is necessary to test the mechanical properties of seamless qb square tubes.It is good to purchase Baosteel's materials for cold drawing of square tubes, because Baosteel's materials are subject to grade flaw detection, and the density of steel is relatively good. After cold drawing and heating, it is convenient to line up. The steel is cold drawn at room temperature to produce plastic deformation,Antigo kuscatland300 square tube, so as to improve the yield strength. This process is called cold drawing strengthening. Square tube is generally used for product parts with high requirements. It has good willfulness and strength. The surface is better after cold drawing. Cold drawing principle.Interpretation and observation,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.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.Principle of cold drawing strengthening: the lattice defects of steel increase during plastic deformation, 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.

For structure: as pile driving pipe and bridge; pipe for wharf, road and building structure, etc.Where is good, heat strength steel and air valve steel; c. Electric heating alloy steel; d. Wear resistant steel; e. Low temperature steel; f. Electrical steel.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.Mechanical engineering, agricultural and chemical machinery, glass curtain walls, automobile chassis, airports, boiler construction highway railings, housing construction, pressure vessels, oil storage tanks,Antigo kuscatlandSpecification and model of galvanized pipe, bridges, power station equipment, 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.Antigo kuscatland,The strength, plasticity and angle discussed later are the machine function indicators of metal under static load. In practice, many mechanical machines are under repeated load, and the whole opportunity is tired in this environment.The advantage of empty bending is that it can bend the side length when the real bending cannot be carried out, such as synchronous bending and finishing of the upper side and side of qb square tube. Empty bending can also bend the inner corner of r.t without breaking the tube wall.With the progress of the times and the development of science and technology, the application fields of square tubes are widely divided. The main fields are the construction industry. Affected by the environment and weather, square tubes will also rust for a long time. How to improve the rust resistance of square tubes and what are its rust resistance? Let me give you a detailed introduction below.