Empty bending empty bending is the bending moment formed in one direction between the outer roll and the outer wall of the tube blank to bend the strip. Empty bending will compress the bending line, the compression effect will lengthen the bending line longitudinally, and the metal at the bending will accumulate and thicken, which is the compression thickening effect of empty bending.Purpose of square tube the purpose of square tube includes construction, machinery, steel construction and other projects, shipbuilding, solar power generation support, steel structure engineering, electric products ( pieces)Schiedam ,Low alloy steel is divided into q Mn, Q, St-, etc.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, 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, 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, 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, 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, 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,Schiedam 10mm square tube, 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 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 goodAnew,We all know very well. Therefore, the quality of square tubes will directly affect the development of the construction industry. What if we can make the service life of square tubes longer? Here, we also need to ask the personnel of the square tube manufacturer for instructions, and use ingenious methods to prolong the service life of the square tube, so that the square tube can bring us greater help in life.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.The characteristics of square pipe are as follows: the production process of square pipe is simple, the production efficiency is high, the cost is low and the development is fast. The strength of spiral square pipe is generally higher than that of straight seam square pipe. It can produce square pipe with larger pipe diameter with narrow blank, and square pipe with different pipe diameter with blank of the same width. However, compared with straight seam pipe of the same length, the weld length is increased by ~, square rectangular tubes, seamless square tubes, galvanized square tubes, galvanized tubes, on-site settlement, honest operation, local offices long-term cooperation, and low production speed. Therefore, most of the smaller square tubes adopt straight seam welding,Schiedam 100 price of galvanized pipe, and most of the large-diameter square tubes adopt spiral welding.
Large diameter qb square tube production standard classification square tube is divided according to production standard: national standard square tube, Japanese standard square tube, American standard square tube, European standard square tube and non-standard square tube.With the development of economy there are a lot of demands for project construction, which leads to the continuous increase of square pipe. The of square pipe is more complex. Great efforts should be made in the selection of raw materials, structured treatment and so on.Principle of cold drawing strengthening: the lattice defects of steel increase during plastic deformation, 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.Free consultation,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.Main uses of square tube: square tube is mainly used in tap water engineering, petrochemical industry, chemical industry, electric power industry agricultural irrigation and urban construction. It is one of the key products developed.Hot dip galvanized square pipe is widely used, mainly in curtain wall, solar power generation support, construction, machinery and steel structure engineering, especially in curtain wall, machinery and construction. The effect of cold galvanized square tube is far from that of hot galvanized square tube; How to distinguish hot galvanized square pipe from cold galvanized square pipe?
Normalized: A. pearlite steel; b. Bainitic steel; c. Martensitic steel; d. Austenitic steel.Where is it,Square tube is a very good steel in economic construction. There are many kinds and principles of cold drawing. You may still have a lot of insufficient understanding of the cold drawing principle of each other's pipe. Next, I'll lead you to learn its cold drawing principle.The general delivery length of square pipe is mm-mm, 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 % of the nominal wall thickness when the wall thickness is not greater than mm, plus or minus % of the wall thickness when the wall thickness is greater than mm, except for the wall thickness of corners and weld areas. The weight of short gauge and non fixed gauge products shall not exceed % of the total delivery. For square tubes with a theoretical weight greater than kgm, it shall not exceed % 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, we will mainly explain the characteristics of pipe cooling technology below. What are the main characteristics of square tubes? Square tube parts have accurate dimensions and smooth surfaces: the dimensional accuracy of cold parts developed at present can reach grade ~ . If ideal ones are adopted, 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).C. special performance steel: (a) stainless and acid resistant steel; (b) Heat resistant steel; (c) Electric heating alloy steel; (d) Electrical steel; (e) High manganese wear resistant steel.Schiedam 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.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.Change to square pipe: generally, the strip steel is unpacked, leveled, 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. Stage ( & mdash; )