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 q355b square tube. Empty bending can also bend the inner corner of r0.2t without fracture of pipe wall. The disadvantage of empty bending is that when the upper side and side are synchronous empty bending, 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, resulting in edge instability and concave and will also affect the stable operation of the unit and forming quality. This is also the different characteristics of q355b square tube and round tube empty bending.
How to specify the yield point of square tube: if the stress decreases, the upper and lower yield points shall be distinguished. The unit of yield point is nmm2 (MPa
Sabanilla.Purpose of square tube the purpose of square tube includes construction, machinery, steel construction and other projects, shipbuilding, solar power generation support steel structure engineering, electric products (3 pieces)
After the square pipes are stacked and stored, the pipe end protector shall be removed to avoid moisture gathering on the surface of the pipe end protector and the square pipe, which is difficult to volatilize.
.Square tubes shall be stored with supports, square rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes are safe and secure. They shall be at a certain distance from the ground to ensure the ventilation of square tubes.
Tensile strength: 490-675 yield strength: & Ge; 345 elongation: & Ge; 22 mechanical properties of seamless pipe: tensile strength: 490-675 yield strength: ≥ 345 elongation: & Ge; 21 mechanical properties of seamless pipe: tensile strength: 490-675 yield strength: ≥ 345 elongation: & Ge; 21 mechanical properties of seamless pipe: tensile strength: 490-675 yield strength: ≥ 345 elongation: & Ge; 22 mechanical properties of seamless pipe: tensile strength: 490-675 yield strength: ≥ 345 elongation: & Ge; 22 square tube belongs to low alloy series. It is one of the materials of seamless steel pipe. In low alloy materials, this material is ordinary. Square tube used to be called Q345B square tube.
Functional index analysis of square tube - commonly used are square tube Brinell angle (HB), Rockwell angle (hrahrbhrc) and Vickers angle (HV) Equal angle is a gauge needle to weigh the soft and hard level of metal data. In the current life, the angle method is rarely used to determine the angle. It uses the indenter with a certain number and shape to determine the angle value of the metal data surface being tested under a certain load according to the level.
After time, the workpiece forms an oxide film with a fixed thickness and presents various colors. Chemical oxidation method is to form various film colors in a specific solution at temperature and time; Because of the law & rdquo; More, the reference electrode must be used. Electrochemical method is to form the color of chloride film with fixed thickness in specific electrolyte at temperature, voltage and time. This process is mature and widely used. Ion implantation method is to vaporize ions in vacuum and deposit them on the surface of q355b square tube such as watch case on the market. The golden color of watch strap adopts this process technology, which is suitable for mass production. The process of gas phase cracking is more complex and less used in industry. Square tube has long been widely used in mechanical industry. When the square pipe is cut automatically, when the square pipe is hoisted to the gas cutting platform, the distance difference between the two ends of one side of the pipe and the guide rail shall be adjusted within 5mm. During semi-automatic cutting, the guide rail shall be placed on the plane of the cut pipe, and then the cutting machine shall be placed on the guide rail gently.
For gas transmission: gas, steam and liquefied petroleum gas.
After RH treatment, the molten steel should be fed with Si Ca line when the molten steel temperature is high. At this time, calcium treatment can reduce sulfur segregation in the later solidification process.
knowledge.Surface adhesion resistance is an important feature of square tubes. At present, square tubes are mostly used for transportation, also known as square and rectangular cold-formed hollow section steel, is referred to as square pipe and rectangular pipe for short. The allowable deviation of wall thickness of square pipe is f and J q355b respectively. When the wall thickness is no more than 10mm, it shall not exceed plus or minus 10% of the nominal wall thickness. Long term square pipe, rectangular pipe, seamless square pipe, galvanized square pipe, galvanized pipe, 20-year-old brand, price advantage and quality guarantee! When the wall thickness is greater than 10mm it is plus or minus 8% of the wall thickness, except for the wall thickness of corners and weld areas.
After the process of polishing, the surface effect of the square tube is quite good. The quality of the polishing process directly affects the external image of the square tube. Therefore, we must choose the appropriate polishing according to the above, and pay more attention to the polishing process of the square tube.
Effective treatment of square tube coating & ldquo; Surface defense line & rdquo; Surface technology and measures square tube coating is used as the back course & ldquo; Surface defense line & rdquo; The surface treatment technologies and measures can be carried out on the basis of other surface treatment technologies or processes. Here's the & ldquo; Surface treatment before coating & rdquo; It refers to all treatment measures for preparation for coating or joint protection with coating. Therefore, mm; L0 -- original gauge length of sample, mm. Reduction of area (& psi;) in the tensile test, the percentage between the large reduction of the cross-sectional area at the reduced diameter and the original cross-sectional area after the specimen is broken is called the reduction of area. In & psi; Expressed in%. The calculation formula is as follows: where: S0 -- original cross-sectional area of the sample, mm2; S1 -- small cross-sectional area at the reduced diameter after sample breaking, mm2.
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 square tube is formed by external control or internal control roller.
Sabanilla.The performance advantage of square tube after calcium treatment requires not only high strength, but also good machining performance. For sulfur-containing square tube, sulfur can improve the machinability of steel, so the sulfide inclusion in square tube is the key to determine the quality of steel. Sulfur mainly exists in the form of MNs in the steel. The single MNS inclusion is light black strip. The inclusion with this morphology cuts off the continuity of the steel matrix and makes great differences in the anisotropic properties of the steel. Calcium treatment of molten steel can inhibit the formation of MNS inclusions and combine MNS with al20 CAS to form composite spindle inclusions. Such inclusions can improve the machinability of steel and avoid the adverse impact of MNS inclusions on the properties of steel.
After the square pipes are stacked and stored, the pipe end protector shall be removed to avoid moisture gathering on the surface of the pipe end protector and the square pipe, which is difficult to volatilize.
Square tubes have a good performance in practical application. When we choose square tubes in practice, we should choose them according to their characteristics. We have different types of square tubes in different fields. What is the difference between the characteristics of square tubes and ordinary steel tubes? Let's introduce them today to let us have a deeper understanding of each other's tubes.