Square pipe， the steel pipe whose ratio of outer diameter to wall thickness is less than is called square pipe. At present， the square tubes produced by qb square tube factory are mainly used in tap water engineering， petrochemical industry， chemical industry， electric power industry，Large diameter square tube agricultural irrigation and urban construction. For transportation: water supply and drainage. For gas transmission: gas，Galvanized square pipe factoryCritical stress of industry steam and liquefied petroleum gas. For structure: as pile driving pipe
9Now， Fangguan can achieve such good results in the market， which is completely inseparable from the manufacturers hard work in technology. I believe that the Fangguan market will be better and better in the future.
mFerroalloy is an alloy composed of iron and silicon， manganese， chromium， titanium and other elements. Ferroalloy is the raw material for steelmaking. It is used as deoxidizer and alloy element additive for steel in square tube steelmaking.
It is forbidden to degrease the oil square pipes and pipe fittings in the direct production concentration unit， air separation unit， oil refining and chemical engineering according to the design requirements. The purpose of degreasing is to prevent the transported or stored materials from being contaminated by grease or organic matter; Avoid mixing transported or stored materials with grease or organic matter; Oil content to ensure the activity of the catalyst; The content of oil and organic matter to ensure the purity of the product. The installed square pipe shall be disassembled into pipe sections for degreasing. Pipes that cannot be disassembled after installation shall be degreased before installation. Square pipes with obvious oil stains or serious corrosion shall be cleaned by steam purging， sand blasting or other methods before degreasing.
ZToona sinensisHot rolled qb square tube continuous casting slab or blooming slab is used as raw material，Large diameter square tube heated by stepping heating furnace and descaled by high-pressure water into roughing mill. Roughing material enters finishing mill after head cutting tail cutting and then computer rolling. After final rolling， it is rolled into straight hair coil through laminar cooling and coiler. The head and tail of straight hair curl are often tongue shaped and fish tail shaped， with poor accuracy of thickness and width， and there are often defects such as wave shape， hem， tower shape and so on. The coil weight is heavy and the inner diameter of the steel coil is mm.
WaHardness 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， so as to determine the hardness of the material. Hardness test is simple， 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，Large diameter square tube which is of great practical significance.
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，Galvanized square pipe factoryCritical stress of industry the standards of welded pipes are summarized in turn: galvanized qb square pipe for low-pressure fluid transportation， and the standard number is gbt-. Representative materials: QA， qbqb， etc. It is mainly used for conveying water， gas， air， oil and heating hot water or steam， and is used for general low pressure fluid.
Two main factors should be considered in the design of square pipe section: one is the safety of the section; the other is the economy of the section. For the safety of the section，Galvanized pipe_ Galvanized square pipe_ Seamless steel pipe_ Square tube - Wuxi Jiahang we require that the ratio of waist thickness to height of H-section steel should not be less than . For H-section steel used as column， its economy is expressed by the ratio of torsion radius to its mass.
aNormalized: A. pearlite steel; b. Bainitic steel; c. Martensitic steel; d. Austenitic steel.
EThe level of R-angle square tube is generally - times of the wall thickness. R-angle square tube of the size required by customers can also be produced according to the needs of customers; Square tube is a kind of long steel with hollow section and no joints around. It is a square tube formed by four sides of seamless tube mold. Square tube has hollow section. It is specialized in selling square tube， square rectangular tube， seamless square tube， galvanized square tube， galvanized tube strict testing and quality assurance. In the process of preferential activities， welcome to consult. It is widely used as a pipeline for conveying fluid. It is mainly used in conveying， hydraulic support and mechanical structure， Medium and low pressure， high pressure boiler tubes， heat exchange tubes， gas， oil and other industries. It is stronger than welded and will not crack.
MHigh quality brandThe 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， which is called the yield point.
nAChemical polishing: less investment in processing equipment， high efficiency and good durability. Its defects are poor brightness， gas overflow， which has great similarities with seamless steel pipe， but it is different. Square pipe is of great use in square pipe which is generally used in the field of building materials and pipes. Today we tell you about the painting of square pipe. In fact， most manufacturers need to do this function， it will cost you two sums of money. If painting， it is recommended that you brush zinc rich primer， because you brush other paints， it will corrode quickly， and then continue to corrode your galvanized layer， boiling water tubes for low and medium pressure boilers of various structures and superheated steam tubes you should paint before galvanizing
Be sure to select special for square pipe cutting.
device managementtDo a good job in the following aspects to effectively improve the service life of square tubes
HSquare tubes for low and medium pressure boilers (gb-) are high-quality carbon structural steel hot-rolled and cold drawn (rolled) square tubes for superheated steam tubes， large smoke tubes， small smoke tubes and arch brick tubes for locomotive boilers. Square tubes for high-pressure boilers (gb- is a high-quality carbon steel， alloy steel and stainless heat-resistant steel square tube for the heating surface of water tube boilers with high pressure and above. High pressure square tube for chemical fertilizer equipment (GB - is a high-quality carbon structural steel and alloy steel square tube suitable for chemical equipment and pipelines with working temperature of - ~ ℃ and working pressure of ~ mA.
In the case of dynamic load， plastic design usually calculates the allowable stress 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， it can be calculated by the formula a = W. replacing the calculated strength with plasticity can improve the bearing capacity of the member by %.
fQb square tube， the die material selected， has obvious hardening in the deep drawing process， resulting in a lot of hard metal points， resulting in adhesion. It specializes in selling square tube， square rectangular tube， seamless square tube， galvanized square tube， galvanized tube and other special products. It is an old brand with advantageous price and guaranteed quality. It makes the surface of workpiece and die easy to be scratched and worn. Therefore， tool steel for general die can not be used.
iIThe welding sequence is to reduce deformation. The welding sequence of rectangular butt welding shall adopt layered and symmetrical skip welding from the middle to both sides according to the following principles. The welding deformation is smaller than that of straight through welding， which is conducive to the dispersion and release of stress and avoid complex stress in weldments. During straight through welding， the narrow plastic deformation zone formed at the beginning of welding only occurs once. Moreover， due to continuous welding， the heat input is large， the heating area is large and the plastic deformation area caused by compression is large， so the shrinkage deformation after welding is very large. In case of layered and segmented skip welding， the section of each layer is very small， and the heat required is small， and each layer is divided into several sections for skip welding. Each welding section basically re establishes the secondary temperature field on the cold steel plate， and a narrow plastic deformation zone appears each time. Therefore， the average width of the plastic deformation zone (i.e. the size of transverse shrinkage) is smaller than that of the corresponding layered straight through welding， The welding deformation is smaller than that of continuous filling.
Square pipe is an important pipe. Its application in various fields has different performance. According to its different performance， we have carried out different transformation on the other pipe to ensure that the square pipe can be better used. We should make the right choice when purchasing. Below I will introduce the correct way of painting the lower pipe.