The disadvantage of empty bending is that when the upper side and side are synchronously empty bending, the forming force is easy to exceed the critical point due to the pressure generated by the upper roll and the lower roll at the same time, resulting in edge instability and concave, and will also affect the stable operation and forming quality of the unit. This is also the different characteristics of qb square tube and round tube empty bending. The concept of square tube: square tube is the pressure processing of ingot, billet or square tube Make materials of all shapes, sizes and properties we need.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, 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, 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,LomHot dip galvanized pipe factory, large-diameter steel pipe, forging etc. can be stacked in the open air; Small and medium-sized section steel, wire rod, reinforcement,LomDN80 galvanized water pipe, 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, 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, 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 goodLom,Function index analysis of square tube - strength and plasticity discussed later are machine function indicators of metal under static load. In practice, many mechanical machines are under repeated load employment. In this environment, the whole opportunity is tired.Generally, chemical and electrolytic pickling are used for pickling treatment. Only chemical pickling is used for pipelines, which can remove oxide scale, rust and old coatings. Professional square tubes rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes are safe, environmentally friendly and economical! The products are exported to foreign countries and are deeply trusted. Sometimes they can be used as reprocessing after sand blasting and rust removal. Although chemical cleaning can make the surface reach a certain cleanliness and roughness, its anchor lines are shallow and easy to pollute the environment.Darayya,Hundreds of degrees Celsius, which can save energy.Stage ( & mdash; )If the test results of square tubes fail to meet the provisions of product standards, the unqualified ones shall be selected, the batch of square tubes shall not be delivered. If the following inspection items fail to pass the preliminary inspection, re inspection is not allowed: A. There are white spots in the low magnification; b. Microscopic.

Impact toughness the load acting on the machine part at a great speed by QB is called impact load, Japanese standard square tube, British standard square tube, American standard square tube, European standard square tube and non-standard square tube.Square tube is an essential material for the construction and Realization of industrialization. It is widely used and has a wide variety. According to different section shapes, square tube is generally divided into sections, plates, pipes and metal products. In order to facilitate the production, light rail it is also divided into heavy rail, large section steel, medium section steel, small section steel and square tube cold bending Section steel, high-quality section steel, medium and thick steel plate, sheet steel, electrical silicon steel sheet, strip steel, seamless steel pipe, square pipe, welded steel pipe, metal products, etc.Inspection environment,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, so it must be densified, usually pressurized during the reaction.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.Hot dip galvanized square tube is a kind of square tube which is welded after using steel plate or steel strip to curl and form, and on the basis of this square tube, the square tube is placed in the hot dip galvanized pool and formed through a series of chemical reactions; The production process of hot-dip galvanized square pipe is relatively simple but the production efficiency is very high and there are many specifications and varieties, but this kind of square pipe needs little equipment and capital, which is more suitable for the production of small galvanized square pipe manufacturers.

In the square tube production process of welding before forming, the forming is mainly completed by the sizing frame. The sizing machine is generally a two high mill, including horizontal frame and vertical roll frame. At present, there are mainly two kinds of square pipe pass design: one is the horizontal frame is designed according to the box hole, the frame is an elliptical hole, and the other frames are approximately rectangular holes. The pass section is composed of circular arc. Professional projects include: square pipe, square pipe, seamless square pipe, galvanized square pipe, galvanized pipe and other related businesses. Please welcome merchants who want to have this business. And the arc radius increases frame by frame, The fillet radius of the joint between the side wall and the bottom of all pass patterns is equal to the fillet radius of the finished section. The total elongation coefficient of the square tube is about , which is mainly distributed on the flat roller. The deformation of the vertical roller is very small, and its function is to press down the short side of the square tube. With this design, the calculation is complex and the calculation value is not accurate enough. It is necessary to constantly correct the pass circumference.Range, resulting in an under current area. The zinc layer at this part is thin, and there is no zinc layer attached to the cold galvanized square pipe. The cold galvanized square pipe has no zinc lump and caking as a whole, but the overall zinc layer is thin, and the thickness of the outer wall zinc layer is μ m-μ m. The and outer walls of the hot-dip galvanized square tube are attached with zinc layer, and there will be water marks and a few zinc tumors but the overall zinc layer is thick, and the thickness of the zinc layer on the inner and outer walls of the square tube is -mu; M above. The nature of QB square tube!Square tube failure. When the pipeline is erected, it is necessary to do a good job or directly use the square pipe. The reason for the corrosion of the pipeline is that the layer of the pipeline is damaged. Once the layer is separated from the pipe surface, it will naturally cause failure.Functional index analysis of qb square tube - mechanical function of plastic square tube. Solid bending, as the name suggests, is to compact the bending. During real bending, the inner and outer rollers and the inner and outer walls of the pipe blank are compacted in both directions.Lom,Precision inner diameter square tubes for hydraulic and pneumatic cylinders (gb-) are cold drawn or cold-rolled precision square tubes with precision inner diameter for hydraulic and pneumatic cylinders.Impact toughness the load acting on the machine part at a great speed by QB is called impact load,Lom40 galvanized square pipe thickness, and the ability of metal under impact load is called impact toughness.When storing QB square pipe, we need to select a suitable place. We need to think about many external factors, such as the corrosivity of steel pipe, etc. Therefore, the place must be clean, dry and ventilated, where harmful gases appear, QB square pipe can not appear, weeds and other sundries should be removed in time, and the outer surface of steel should be kept clean. If there are acid, alkali, salt, it is easy to react with the steel pipe and corrode the steel pipe, so try to cut it and don't let it. In addition, if we can think about those higher metal products, we can put them into the warehouse for very good retention. According to geographical conditions, there is a sealed warehouse, but the ventilation setting is excellent. The difference between QB square tube and seamless steel tube QB square tube is a kind of high-precision steel tube material after cold drawing or hot rolling treatment. QB square tube is mainly used to produce products of pneumatic or hydraulic components, such as air cylinder or oil cylinder, which can be seamless pipe or welded pipe, because there is no oxide layer on the inner and outer walls of QB square tube, no deformation under high pressure, high precision, high finish, cold bending, flaring and flattening without cracks. The chemical composition of QB square tube includes carbon silicon Si, manganese Mn, sulfur s, phosphorus P and chromium CR.