Steel for construction and engineering according to the classification of use without phase transformation or partial phase transformation of square tube: A. ordinary carbon structural steel; b. Low alloy structural steel; c. Steel reinforcement.Viewing color: the color of the cold galvanized square tube is yellowish green cyan white or slightly colored at a fixed angle with the sun. The color of hot-dip galvanized square pipe is silver white at a fixed angle with the sun.Lantian,On the basis of thermodynamic calculation, the quality assurance of square tube rectangular tube, seamless square tube, galvanized square tube and galvanized tube is professional. New and old customers are welcome to consult during the preferential activities. The process conditions of calcium treatment of CrMo sulfur-containing square tube are analyzed, and the sulfur-containing gear rolled products after calcium treatment are sampled and studied. The conclusions are as follows: in order to minimize the generation of Cao in sulfur-containing square tube steel, Omega in molten steel; (O) It must be taken off to & times; The rate of calcium can only be guaranteed below -.Fatigue strength, plasticity and hardness discussed above are indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.Calle-Blancos,Mechanical engineering, power plants, agricultural and chemical machinery, glass curtain walls, automobile chassis, airports, boiler construction highway railings, housing construction, pressure vessels, oil storage tanks, 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.The reason why it is divided into two types is that chemical cleaning can only clean the surface very thoroughly, and it is difficult to achieve the desired results in some fine cracks.Strength QB square strength refers to the performance of metal materials under static load (excessive plastic deformation or fracture). Since the action modes of load include tension, compression, bending and shear, the strength is also divided into tensile strength, compressive strength, flexural strength and shear strength. There is often a certain between various strengths. Generally, tensile strength is used as the basic strength indicator. Precision pipe is a seamless pipe with high dimensional accuracy and good surface finish for mechanical structure and hydraulic equipment. The selection of precision seamless mechanical structure or hydraulic equipment can greatly save machining hours, improve material rate and improve product quality. Seamless pipe is rolled in the annular pass composed of variable cross-section circular hole groove and fixed conical plug. Cold drawing is usually carried out on single chain or double chain cold drawing machine. This method is to put the heated pipe blank in a closed cylinder, I'll give you a detailed introduction to the heating technology of the lower tubes.The purity of the square tube has a great impact on the isotropic performance of the square tube. The use of secondary refining technology (including vacuum refining, ESR and ladle powder spraying) can improve the purity of the square tube, especially reduce the content of harmful impurities in the square tube, which is beneficial to improve the performance.The pressurization size and time are the key to the success or failure of welding. If the square tube synthetic material is not pressurized, a large number of pores will be caused due to the pores of the material itself and the gas generated in the reaction. It is not allowed to leave the reactants in the weld, usually pressurized during the reaction.Create brilliance,It is the process of drawing the die hole of the rolled metal blank (shape, pipe, product, etc.) into a section to reduce the length and increase. It is mostly used for cold processing.The technology of floating mandrel and square tube is gradually mature.Strength refers to the performance of metal materials under static load (excessive plastic deformation or fracture). Since the action modes of load include tension, compression, bending and shear, the strength is also divided into tensile strength, compressive strength, flexural strength and shear strength. There is often a certain between various strengths. Generally,Lantian700 square tube, tensile strength is used as the basic strength indicator. Appropriate sites and warehouses shall be selected. The sites or warehouses for storing steel pipes shall be in clean and unobstructed places, away from factories and mines that produce harmful gas or dust. Weeds and sundries shall be removed on the site to keep the steel pipe clean; In the warehouse it is not allowed to stack with acid, alkali, salt, cement and other materials that are corrosive to the steel pipe. Different types of steel pipes shall be stacked separately to prevent confusion and corrosion; Large section steel, rail, steel plate, large-diameter steel pipe forging, etc. can be stacked in the open air; Small and medium-sized section steel, wire rod, reinforcement, medium diameter steel pipe, steel wire and steel wire rope can be stored in a well ventilated shed, but they must be covered and padded; Some small steel pipes steel sheets, steel strips, silicon steel sheets, or thin-walled steel pipes, all kinds of cold-rolled and cold drawn steel pipes and high and corrosive metal products can be stored in the warehouse; The warehouse shall be selected according to geographical conditions, and generally adopts ordinary closed warehouse, the warehouse with roof, enclosure,LantianStandard for galvanized pipe, close and damp proof in rainy days, and often maintain a suitable storage environment. The principle of reasonable stacking and first in first stacking is to stack according to varieties and specifications under the condition of stable stacking and ensuring safety. Materials of different varieties shall be stacked separately to prevent confusion and mutual corrosion; It is forbidden to store articles that have corrosive effect on steel pipes near the stacking position; The bottom of the stack shall be padded high,LantianGalvanized square tube merchant, firm and flat to prevent the material from moisture or deformation; The same kind of materials shall be stacked according to the warehousing order, so as to facilitate the implementation of the principle of first in, first out; The section steel stacked in the open air must be provided with wooden mats or strip stones. The stacking surface is slightly inclined to facilitate drainage. Pay attention to the straightness of the material placement to prevent bending and deformation; The stacking height shall not exceed m for manual operation, m for mechanical operation, and m for stacking width; A fixed channel shall be reserved between stacks, generally .m, and the access channel is generally ~ om depending on the size of materials and transportation machinery; The bottom of the stack shall be padded up. If the warehouse is cement floor, it can be padded up by .M; If it is muddy ground, it must be padded . ~ .m high. If it is an open site, the cement ground shall be padded with O & middot; ～O· m, . ~ . m higher than the sand and mud surface, the angle steel and channel steel shall be stacked in the open air, i.e. the mouth shall face down, and the I-beam shall be placed vertically. The i-groove surface of the steel pipe shall not face up to avoid ponding and rust. The packaging and protective layer of the protective materials shall be coated with agent or other plating and packaging before leaving the factory, which is an important measure to prevent material corrosion. Attention shall be paid to protection during transportation, loading and unloading and shall not be damaged, The storage period of materials can be extended, the warehouse shall be kept clean and the maintenance of materials shall be strengthened. Before warehousing, materials shall be prevented from being drenched or mixed with impurities. Materials that have been drenched or contaminated shall be wiped according to their properties, cotton and other materials for low hardness; The materials shall be regularly after warehousing. If there is corrosion, the corrosion layer shall be removed; Generally, the steel pipe surface does not need to be coated with oil after being cleaned, but for high-quality steel alloy steel sheet, alloy steel pipe, the internal and external surfaces need to be coated with anti rust oil before storage; Steel pipes with serious corrosion shall not be kept for a long time after rust removal and shall be used as soon as possible. With the development of economy, all kinds of square tubes, rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes have been recognized by the majority of customers for a long time. There are more and more counterfeit products on the market. In order to prevent being deceived when you are in square tubes, you need to know some knowledge about how to judge the authenticity of square tubes: & ldquo; We can judge by observing the surface and flatness of the square tube. If the surface of the square tube is relatively flat, it can reflect that the square tube is good. On the contrary, if the surface is not good

Section shape classification square tubes are classified according to section shape: simple section square tubes & mdash& mdash; Square tube, rectangular tube and complex section square tube & mdash& mdash; Surface treatment classification of flower shaped square pipe, open square pipe, corrugated square pipe and special-shaped square pipe square pipe is divided into hot-dip galvanized square pipe, electro galvanized square pipe, oil coated square pipe and pickling square pipe according to surface treatment. Square pipe is classified according to purpose & mdash& mdash; Square tubes for decoration, machine tools and equipment, machinery industry, chemical industry, steel structure, shipbuilding, automobile, steel beam and column and special purpose are classified by wall thickness & mdash& mdash; Super square tube, square tube and thin-walled square tube plasticity refers to the ability of metal materials to produce plastic deformation (deformation) without deformation under load.query,Compared with other welding, mainly because of the exothermic reaction, the material only needs to be heated below the melting pointIt 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.Comprehensive classification ordinary steel A. carbon structural steel: (a) Q (b) Q (b); (c) Q( C)； (d) Q( B)； (e) Q.Lantian,Mechanical engineering, power plants, agricultural and chemical machinery, glass curtain walls, automobile chassis, airports, boiler construction, highway railings, housing construction, pressure vessels, oil storage tanks, 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.The reason why it is divided into two types is that chemical cleaning can only clean the surface very thoroughly, and it is difficult to achieve the desired results in some fine cracks.The first is to remove the rust of the square tube. When removing the rust of the square tube, the steel wire brush is mainly used to polish its surface, which can effectively remove the loose or rusty rust on the surface of the square tube.