Welding seamless welding seamless is to make welded elbows. After grinding and pickling, sand blasting, there is no sign of welding on the surface. Even using advanced flaw detection equipment, it can not be seen that they are welded elbows.A. square tube structural steel: (a) high quality carbon structural steel; (b) Alloy structural steel; (c) Spring steel; (d) Easy cutting steel; (e) Bearing steel; (f) High quality structural steel for specific purposes.Guatemala,Preheating must be carried out before heat treatment of qb square tube, so as to better ensure that there will be no many problems in the whole heat treatment process of qb square tube, and the quality of qb square tube will also be well guaranteed.The second is the pickling of the square pipe. Both chemical and electrolytic methods are used when pickling the square pipe. These two methods can remove the oxide skin of the square pipe.Corsingborg,With the improvement of production quality, the quality of square tubes is getting better and better. The quality of square tubes will affect our lives. Because the functions of square tubes are different, their characteristics and uses are different. I will introduce the characteristics and uses of square tubes in detail.Square tube is made of different materials. It needs qualified inspection by relevant staff before leaving the factory. Square tube has a wide range of uses. Its main field is not only the construction industry, but also can be seen everywhere in our daily life. The service life of square tubes is mainly affected by surface treatment. I will explain the specific operations of surface treatment of square tubes.Because the green billet can be pressed into any shape, it is easy to weld the square tube into difficult products.

Oil drilling pipe (yb-) is a square pipe used for internal or external thickening at both ends of oil drilling. Steel pipes are divided into turning wire and non turning wire. Turning wire pipe is connected with joint and non turning wire pipe is connected with tool joint by butt welding.Preheating must be carried out before heat treatment of qb square tube, so as to better ensure that there will be no many problems in the whole heat treatment process of qb square tube, and the quality of qb square tube will also be well guaranteed.Hardness hardness is a pointer to measure the hardness and softness of metal materials. At present, the hardness method is commonly used to measure the hardness in production. It uses the indenter with fixed geometry to measure the hardness value of the metal material surface tested under fixed load according to the degree of hardness.For more please check,Ship carbon steel square pipe (gb-) is a carbon steel square pipe for ship class I pressure pipe system class II pressure pipe system, boiler and superheater. It is a long-term business square pipe, square pipe, seamless square pipe, galvanized square pipe and galvanized pipe. Welcome to consult. The working temperature of carbon steel square pipe wall shall not exceed ℃, and the working temperature of alloy steel square pipe wall shall exceed ℃.Section shape classification square tubes are classified according to section shape: simple section square tubes & mdash& mdash; Square tube, 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,Guatemala50 galvanized round pipe, 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.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.

Square tube, modified square tube, square tube, QB square tube and hot-rolled square tube are qualified in quality inspection. The manufacturer adopts advanced equipment to ensure the quality of each product. Magnetic flux leakage testing for surface defects of square tubes is very similar to magnetic particle testing for square tubes, sensitivity and reliability are stronger than magnetic particle testing. Indirect square forming process the traditional forming process of cold-formed square pipe is to gradually roll the hot-rolled steel coil multi stand forming unit into round pipe at room temperature, and then the shaping unit will roll the round pipe into square pipe, which is called indirect square forming process. The traditional roll forming process uses the method of fixed bending point position and variable bending radian to complete the corner forming of pipe blank, which is suitable for rolling small and medium-sized products. Rolling with this process & ldquo; Superb & rdquo; Square tube will show its inherent defects. Because the roll work in the bending process of this process is always concentrated at the point, excessive stress concentration often shows microcracks in the bending process of profiles, which will lead to cracking in serious cases. The products with such defects have serious consequences when they are used in building steel structures. The study of the broken square tube column in the Hanshin earthquake in Japan shows that the corner microcrack is the main cause of the square tube fracture. At the same time, due to the different forming bending radians of products with different wall thickness, the universality of rolls is limited. The large-size cold-formed square tube used in the process adopts the advanced & ldquo; Direct Square & rdquo; The production process is to directly roll the hot-rolled steel coil into a square and rectangular shape at room temperature.plan,The principle of straightening machine is that a disc is divided into two sides to clamp round steel straight lines. Professional square tube, seamless square tube, galvanized square tube, service, on-site settlement, honest operation! The edge is one with radius r, and the other outer edge must be two equal diameters with radius R. The diameter of the reinforcement to be straightened is D, and the center distance between them is adjusted to R + R + D.The common surface treatment of square pipe includes surface treatment, chemical treatment, shot blasting treatment, manual mechanical treatment and flame treatment. The treated will be separated. ~ Mpa compressed air entrains abrasives, and the nozzle sprays to the steel surface at high speed. The impact and friction of abrasives remove the oxide scale,GuatemalaPrice list of galvanized rectangular pipe, and make the steel surface reach a certain roughness.Square tubes for petroleum cracking (gb-) are furnace tubes, heat exchangers and pipeline square tubes suitable for petroleum refineries.Guatemala,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. Appropriate sites and warehouses shall be selected. The sites or warehouses for storing steel pipes shall be in clean and unobstructed places, alkali it is not allowed to stack with acid, 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, 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,GuatemalaPrice list of 6m galvanized square pipe, 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, that is, the warehouse with roof, enclosure, tight doors and windows and ventilation devices; The warehouse is required to pay attention to ventilation in sunny days, 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, 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, such as steel wire brush for high hardness and cloth, 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, thin-walled pipe, alloy steel pipe etc., 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 goodFatigue 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.Principle of cold drawing strengthening: the lattice defects of steel increase during plastic deformation, and the serious distortion of defect lattice will hinder the progress and slip of lattice, so the yield point of steel increases and the plasticity and toughness decrease. Due to the internal stress in plastic deformation the modulus of steel decreases. The cold drawn reinforcement is stored at room temperature for ~ d or heated to ~ ℃ and maintained for a fixed time. This process is called aging treatment.