The disadvantage of empty bending is that during synchronous empty bending at the upper and side, due to the pressure generated by the upper roll and the lower roll at the same time, the forming force is easy to exceed the critical point. All kinds of square tubes, square rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes have formal qualifications. Welcome to telephone inquiry and sincerely invite cooperation! It will cause edge instability and concave, and will also affect the stable operation of the unit and forming quality. This is also the different characteristics of qb square tube and round tube empty bending.The strength, many machine parts work under cyclic load, under which fatigue will occur.frankincense,The new improvement ensures that square tubes can be used for a long time. With the development of the times, square tubes are used in more and more fields. So how can we correctly choose square tubes? Next, I'll introduce the process of lower tubes.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.Shunhua City, cold drawn tubes, tubes, etc. Hot rolled seamless tubes are produced on the automatic precision tube precision tube rolling mill. The solid tube blank is cut into the required length by removing surface defects, centering on the end face of the perforated end of the tube blank, and then sent to the heating furnace for heating. It is perforated on the piercing machine. At the same time, it rotates and advances continuously under the action of roll and plug, A cavity is gradually formed inside the pipe blank, which is called the rough pipe, and then sent to the automatic pipe mill for continuous rolling. After the wall thickness is adjusted by the whole machine and the diameter is determined by the sizing machine to meet the specification requirements. The continuous pipe mill is more advanced in producing hot-rolled seamless steel pipe. If you want to obtain seamless pipe with smaller size and better quality, Cold rolling and cold drawing must be adopted, or the combination of cold rolling and cold drawing is usually carried out on the roll mill. The seamless pipe is rolled in the annular pass composed of variable section circular hole groove and fixed conical plug. Cold drawing is usually carried out on the single chain or double chain cold drawing machine, that is, the heated pipe blank is placed in a closed cylinder, and the perforated rod and rod move, This method can produce steel pipe with small diameter. In the building materials industry, the development of various pipes is different. Because of their different characteristics, there is a certain distance between pipes. Square pipe is one of many pipes in the building materials industry. It is formed after strip steel treatment. We need to understand the various characteristics of steel pipes. However, the development of various pipes is different. Because of their different characteristics, there is a certain distance between pipes. Square pipe is one of many pipes in the building materials industry. It is formed after strip steel treatment. The various characteristics of steel pipe need to be understood by everyone. However, due to the of steel pipe and other raw materials, the storage of steel pipe needs specific conditions.Qb square tube, qb square tube, qb square tube, QB square tube, but their uses are very different. The shape is different. Qb square tube is a cuboid the bearing capacity of steel is the same, and I-beam is in I-shape. The purpose is different. I-beam can be used as span and support. Square pipe is a little worse than span. It is no problem to do support. However, the specific selection of steel depends on the requirements of the project. Square tube practical application square tube for structure (gbt-) is a square tube for general structure and mechanical structure.Square tube has a wide range of application fields. Its main field is the construction industry, which promotes the development of economic construction. Because the production process of square tube hole is different, the production design of square tube hole is also different. Next, I will introduce in detail the types of tube hole design below.

When the vehicle is replaced with seamless square tube blank, the material is too soft to affect the requirements so as to ensure the quality of parts and avoid wrinkles.During the storage of square tubes, pay attention to the stacking layers of square tubes to avoid local stress at the tube end caused by too many layers, resulting in radial plastic deformation and layer damage of square tubes. It is recommended that the stacking layers of smooth pipes refer to apirp l- Recommended Practice for railway transportation of square pipes for pipelines or apirp lw- Recommended Practice for ship and sea vessel transportation of square pipes for pipelines. It can also be determined by test or implemented according to the safe stacking height of square pipes. The stacking layers of pipes shall be implemented according to GBT - polyethylene layer of buried steel pipelines.B. low alloy structural steel C. ordinary structural steel and high-quality steel for specific purposes (including high-quality steel)How many?,The difference between hot-dip galvanized square pipe and cold-dip galvanized square pipe is mainly from the following aspects: the appearance of hot-dip galvanized square pipe is slightly rough compared with cold-dip galvanized square pipe; The appearance of cold galvanized square pipe is smooth and bright.The inspection items, sampling position and test of square tube shall be in accordance with the provisions of corresponding product standards. With the consent of the demander, hot-rolled square tubes can be sampled in batches according to the rolled root array.Because the green billet can be pressed into any shape,frankincense6. How much is a ton of galvanized pipe, it is easy to weld the square tube into difficult products.

Structural stainless steel square pipe (gbt-) is a hot-rolled (extruded, expanded) and cold drawn (rolled) square pipe made of stainless steel for corrosion-resistant pipes, structural parts and parts widely used in chemical, petroleum light textile, food, machinery and other industries.Latest quotation,Section shape classification of large-diameter qb square tube square tube is classified according to section shape: simple section square tube & mdash& mdash; Square tube, rectangular tube and complex section square tube & mdash& mdash; Flower shaped square pipe, open square pipe, corrugated square pipe, special-shaped square pipe, large-diameter qb square pipe surface treatment classification square pipe is divided according to surface treatment: hot-dip galvanized square pipe, electro galvanized square pipe, oil coated square pipe, acid pickling square pipe, large-diameter qb square pipe purpose classification square pipe is classified according to purpose & mdash& mdash; Square tubes for decoration, machine tool equipment, machinery industry, chemical industry, steel structure, shipbuilding, automobile steel beam and column, special purpose, large-diameter qb square tube wall thickness classification, large-diameter qb square tube according to wall thickness Classification & mdash& mdash; Super large diameter qb square pipe, large diameter qb square pipe and thin-wall large diameter qb square pipe rectangular pipe are the names of square pipe and QB square pipe, that is, leveled the strip steel is unpacked, crimped and welded to form a round pipe, then rolled into a square pipe from the round pipe, and then cut into the required length. Usually pieces per bag. Qb square pipe, also known as square and rectangular cold-formed hollow section steel, is referred to as square pipe and rectangular pipe, code f and j respectively. The allowable deviation of wall thickness of qb square pipe shall not exceed plus or minus % of nominal wall thickness when the wall thickness is not greater than mm, plus or minus % of wall thickness when the wall thickness is greater than mm, except for the wall thickness of corner and welding joint area.The normal process flow is as follows: the round steel is perforated to form a tube embryo, then pickling is carried out, the black skin on the outer surface is washed off, and then grinding is carried out. After passing the inspection, the rolling mill or cold drawing and cold drawing are carried out. Annealing is required for wall reduction, but not for air drawing. After forming, annealing and straightening are carried out,frankincenseHow much is processing galvanized square tube, and pickling is tested and stored in the warehouse. Basically, these are the processes. Better manufacturers will perform whitening treatment during annealing to make the surface treatment more beautiful. The narrow blank of square pipe can produce welded pipe with larger diameter, and the blank of the same width can also produce welded pipe with different diameter. However, compared with the straight seam square pipe with the same length the weld length increases by %, and the production speed is low. Square pipes with large or thick diameter are usually made of steel blank directly, while small welded pipes and thin-walled welded pipes only need to be directly welded with steel strip. Then after simple polishing, wire drawing is OK. Therefore, straight seam welding is mostly used for relatively welded pipes, and spiral welding is mostly used for large-diameter welded pipes.There are many ways of ignition, such as arc, flame, strong current, high-temperature furnace, electron beam, laser, high-temperature radiation, microwave, chemical furnace, etc.frankincense,Square tube plays an important role in the rapid economic development. The functions of square tube are different, and its characteristics are also different. Square tube has strict standards. There are many welding processes and advantages of square tube. Let me show you the welding process and advantages of lower tube.When sand blasting or manual mechanical derusting is used, due to the falling off of the oxide scale of the galvanized square pipe, the metal on the surface of the galvanized square pipe is directly exposed in the air. If a primer is not applied in time, the surface of the galvanized square pipe is easy to rust again, affecting the adhesion of the paint film. I am engaged in all kinds of square tubes, square rectangular tubes, galvanized square tubes,frankincenseDN25 galvanized welded pipe, galvanized tubes and other materials all year round. I operate in good faith. Welcome to call! As the paint is a time-effective material, the overstock of inventory is easy to expire. Therefore, the main indexes of the paint must be rechecked before use, and the paint can be used only when the results meet the standards.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, and its scope of application, 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.