The welding process of square tube is analyzed. The square tube is produced and processed at room temperature with strip steel as raw material. Square pipe can be divided into straight seam welded pipe, square pipe and spiral welded pipe. Due to the different uses of welded pipes, the standards of welded pipes are summarized in turn: galvanized q355b square pipe for low-pressure fluid transportation, and the standard number is gbt3091-2008. Representative materials: Q235A, q235bq345b, etc. It is mainly used for conveying water, gas, air, oil and heating hot water or steam, and its purpose is limited to general low pressure fluid.
Brinell hardness, Rockwell hardness and Vickers hardness are commonly used.
Milwaukee.Special performance steel: A. stainless and acid resistant steel; b. Heat resistant steel: including oxidation resistant steel, heat strength steel and air valve steel; c. Electric heating alloy steel; d. Wear resistant steel; e. Low temperature steel; f. Electrical steel.
In the process of square pipe, we will conduct a variety of tests on it to ensure that the square pipe can be better used in practice. In order to make better use of large-diameter steel pipe, we will continue to innovate. Let's introduce the main elements contained in the lower pipe. For the martensitic chromium square tube, the main elements affecting the are chromium, carbon and molybdenum; For Martensitic chromium nickel square tube, the main influencing elements are nickel, molybdenum aluminum, nitrogen and titanium.
.You can really feel that the square tube is widely used in the development cobalt, and q355b square tube factory continues to extend in the technical level, which makes the current square tube develop more widely.
Section shape classification square tube is classified according to section shape: simple section square tube: square tube, rectangular square tube.
Shot blasting is a high-speed rotating impeller that throws small steel shot or small iron shot out and hits the surface of the square tube at high speed, so the oxide layer on the surface of the square tube can be removed. At the same time, the steel shot or iron shot strikes the surface of the square tube at high speed, resulting in lattice distortion and deformation on the surface of the square tube and increasing the surface hardness
In & sigma; Expressed in%. The calculation formula is: where: L1 -- gauge length after sample breaking, 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.
Reinforcing phases such as reinforcing particles, short fibers and whiskers can be added to the solder to form composites.
The calculation method theory of square tube mechanics is feasible to calculate static structures,MilwaukeeHow much is a galvanized square tube, such as warehouses, houses and bridges, but it is not suitable for moving components such as wheels. At this time, people often use the plastic theory. The research of the plastic theory can be traced back to 1914. In 1975, the European Design Association formulated D plastic design code, which is mainly used for plane beams under static load and bending stress For the frame structure with stress, the requirements are as follows:% 26sigma; B% 26sigma;% 26zeta;% 26ge;% 26delta;% 26ge; 15% for high-rise buildings, more detailed calculation is required. In the case of plastic design, the allowable stress is usually calculated according to the safety factor that the allowable stress is not less than the dynamic load and multiplied by the allowable stress. In the case of bending of an axis, the formula a = w can be used Using plasticity instead of calculated strength can improve the bearing capacity of members by 14%.
quality standard.Square tube is made of steel ingot or solid tube blank through perforation, and then made by hot rolling, cold rolling or cold drawing. Square pipe plays an important role in steel pipe industry.
Tensile strength of square tube (& sigma; b): the stress (& sigma;) obtained by dividing the force (FB) borne by the sample during breaking by the original cross-sectional area (so) of the sample during stretching, and the unit is nmm2 (MPA). It represents the large capacity of metal materials under tension.
Should choose, in the end is galvanized or paint; For paint, it is recommended to match: epoxy zinc rich 50um + epoxy micaceous iron intermediate paint 80um + polyurethane finish paint 60um. In this way, according to the standard of iso12944, which is not a big problem.
Use classification square tubes are divided into: square tubes for decoration, square tubes for mechanical industry, square tubes for chemical industry, square tubes for steel structure, square tubes for shipbuilding, square tubes for automobile, square tubes for steel beams and columns,MilwaukeeHot dip galvanized plastic coated steel pipe, and square tubes for special purposes.
Analysis project.Performance index analysis fatigue of square tube the strength, plasticity and hardness discussed above are the indicators of the mechanical properties of metal under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.
Generally, chemical and electrolytic methods are used
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.
Milwaukee.You can really feel that the square tube is widely used in the development and q355b square tube factory continues to extend in the technical level, which makes the current square tube develop more widely.
Galvanized q355b square pipe for low pressure fluid transmission, Standard No.: gbt3092-2008. The representative material is the same as above. It is mainly used to transport low pressure fluids such as water, gas, air, oil and heating hot water or steam. The surface of square pipe adopts hot galvanizing or cold galvanizing process.
The square tube represents the large capacity of the metal material under the action of tension, and the calculation formula is: where: FB -- the strong force borne by the sample when it is broken, n (Newton); So -- original cross-sectional area of sample, mm2. Yield point (& sigma; s) the stress of metal material with yield phenomenon when the specimen can continue to elongate without increasing (keeping constant) the force during the tensile process