The general delivery length of square pipe is 3200mm-13000mm, mostly 65000mm and 13000mm. The square tube is allowed to deliver short and non fixed length products not less than 2300mm, or in the form of interface tube, but the Demander shall cut off the interface tube when using it. The allowable deviation of the wall thickness of square pipe shall not exceed plus or minus 10% of the nominal wall thickness when the wall thickness is not greater than 10mm, plus or minus 8% of the wall thickness when the wall thickness is greater than 10mm, except for the wall thickness of corners and weld areas. The weight of short gauge and non fixed gauge products shall not exceed 8% of the total delivery. For square tubes with a theoretical weight greater than 20kgm, it shall not exceed 5% of the total delivery. We have many different ways in square tubes. Different ways make square tubes have different characteristics. According to these characteristics, we can correctly select the appropriate application field, In this way, the use efficiency of square tube can be improved. Next, their accuracy is second only to that of fine polished surfaces. Therefore, cold parts generally do not need to be reprocessed and a small amount only need finishing (grinding).
The iron filings and burrs on the cutting section shall be completely removed with a file or appropriate tools to prevent the iron filings and burrs from scratching the rubber O-ring and other accessories when connecting another part.
Pittsburgh.Structural stainless steel square pipe (gbt14975-200) is a hot-rolled (extruded, expanded) and cold drawn (rolled) square pipe made of stainless steel for corrosion-resistant pipes, petroleum, food, machinery and other industries.
The advantages of real bending are small reverse, accurate forming, and as long as the roll shape is accurate, the R of inner corner forming is more accurate.
.Application of square tube products: for mechanical equipment, solar energy equipment, steel structure, automobile parts, bridge ground pile guardrail and ship internal structure.
Square tube failure. When the pipeline is erected, it is necessary to do a good job or directly use the square pipe. The reason for the corrosion of the pipeline is that the layer of the pipeline is damaged. Once the layer is separated from the pipe surface, it will naturally cause failure.
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, the surface treatment before coating is also called coating surface pretreatment.
Preheating must be carried out before heat treatment of q355b square tube, so as to better ensure that there will be no many problems in the whole heat treatment process of q355b square tube, and the quality of q355b square tube will also be well guaranteed.
Stage (1978 & mdash; 1992)
Square tubes are more and more widely used in practice. Different types of square tubes have different characteristics, and the performance of each type of square tube is also different. Choose according to its performance in different aspects, so as to improve its work efficiency. Next, let's introduce what should be paid attention to when heating the lower tube.
Excellent quality.The standard quantity of combustible and nonflammable square pipes is gbt97-1 (gbt97-199). The representative material is l245-l4 pipeline steel. Professional square pipes, square rectangular pipes, seamless square pipes, galvanized square pipes and galvanized pipes are of high quality and low price. They are fire-resistant, waterproof, high temperature resistant, durable, safe and reliable. They are mainly used to transport combustible and nonflammable fluids with high requirements.
Mechanical properties of seamless q355b square tube: tensile strength & sigma; b (MPa)：≥ 980 yield strength & sigma; s (MPa)：≥ 835 elongation & Delta; 5(%)：≥ 12 reduction of area & psi; (%)：≥ 40 impact absorption energy (impact value) (aku2j): & Ge; 39 the products produced by the more complex technology are exquisite. At present, Fangguan is highly praised by the public in the market. What is important is that there is a good guarantee in terms of quality. Therefore, whether Fangguan can obtain such a high market evaluation depends on the complex technology of Fangguan.
Q355b square pipe for mining fluid transportation, Standard No.: gbt14291-2000. The representative material is Q235 grade B steel. It is mainly used for straight seam q355b square pipe for mine air pressure, drainage and shaft gas drainage.
Before gas cutting, remove the dirt and grease on the steel surface, and leave a certain space below to facilitate the blowing out of slag. During gas cutting, the movement of the cutting torch shall be kept at a uniform speed. The cutting surface should be 2 ~ 5mm away from the tip of the flame core. If the distance is too close, the edge of the cut will melt and if it is too far away, the cutting will be interrupted easily due to insufficient heat.
Product survey.Performance index analysis of square tube - plasticity refers to the ability of metal materials to produce plastic deformation without deformation under load.
Stage (1961 & mdash; 1978)
The analytical technology of square tube sizing rolling. When sizing rolling is adopted, because there is no tool on the inner surface, the shape of the inner surface of the rolled material is not neat when rolling the tube. When the roll mill is used, the inner surface of the rolled material is angular. The occurrence mechanism of this phenomenon and the countermeasures to be taken are clarified by using the three-dimensional finite element method.
Pittsburgh.Surface adhesion resistance is an important feature of square tubes. At present square tubes are mostly used for transportation, so the adhesion resistance makes square tubes not stick during transportation.
Hardness test is to use a hard indenter to slowly the sample surface according to the specified conditions, and then test the indentation depth or size, rapid and easy to implement in material mechanical property test. Hardness test is non-linear, and there is an approximate conversion relationship between material hardness value and tensile strength value. The hardness value of material can be converted into tensile strength value, which is of great practical significance.
The strength of square tube refers to the function that the data of square tube are destroyed under static load (appropriate plastic deformation or fracture). Because the action forms of load include tension, contraction, meandering, shear and so on, because the strength is also divided into tensile strength, compressive strength, flexural strength, shear strength and so on. There is often a definite connection between various strengths. In normal use, tensile strength is often used as the fundamental strength gauge.