The general delivery length of qb square pipe is mm-mm, mostly mm and mm. Qb square tube is allowed to deliver short length and non fixed length products not less than mm, or in the form of interface tube. fake and inferior square tubes are easy to fold. Folding is a variety of broken lines formed on the surface of square tubes, and this defect often runs through the longitudinal direction of the whole product. The reason for the folding is that the fake and shoddy manufacturers pursue the rate, the reduction is too large, folding occurs during the next rolling, the folded products will crack after bending, and the strength of the square tube will be greatly reduced.Moita,Stainless steel qb square pipe for fluid transportation, Standard No.: gbt-. The representative materials are Cr crni crni cr crninb, crnimo, etc. It is mainly used to transport low-pressure corrosive media.Spraying (throwing) derusting spraying (throwing) derusting is that the high-power motor drives the spraying (throwing) blade to rotate at high speed, so that the steel sand, steel shot, iron wire section, minerals and other abrasives can be sprayed (thrown) on the surface of the square tube under the action of centrifugal force, which can not only completely remove rust, oxides and dirt, but also the square tube under the violent impact and force of abrasives, It can also achieve the required uniform roughness.Tando Adam,After chemical pickling, the square tube can be well protected by electrolysis. These are simple ways to prolong the service life of the square tube, We only need to treat according to these, so that the square tube can bring us great help in the use process. The cold galvanized square tube is the principle of cold galvanizing on the square tube used to make the square tube have corrosion performance. Different from hot-dip galvanizing, cold galvanizing coating is mainly carried out according to the electrochemical principle. Therefore it is necessary to ensure the sufficient of zinc powder and steel, resulting in electrode potential difference, so the steel surface treatment requirements are very high.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.For improper stamping direction, simulation software shall be used in the initial stage of design to ensure that the direction of stamping parts is analyzed, and when the high-quality requirements of components require the re development of molds, the direction shall be adjusted to seamless square tubes. The square tube manufacturer introduces the forming, bending and bending of square tubes. As the name suggests, the bending is compacted, and the inner and outer rollers are double with the inner and outer walls of tube billets during actual bending Compact towards the.

At this time, if the welding wire of the same material is used for spot welding where the thickness is insufficient, it shall be welded to the fixed thickness, ground and sandblasted, and repair welding shall be adopted where there are cracks, even if the steel pipe with another large opening can be made up at one time.Be sure to select special for square pipe cutting.Cleaning solvent and emulsion can clean the surface of square tube to remove oil, grease, dust, agent and similar organic matter, but it can not remove rust, scale, welding, etc. on the surface of square tube, so it is only used as an auxiliary means in production.new product,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, 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, 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,MoitaHow much is the galvanized square tube, 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, 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, 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 goodGenerally, the adobe has cracks due to the action of thermal stress, 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, 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, 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, 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, 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, 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,Moita46 price of galvanized square pipe, 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, it can reflect that the square tube is good. On the contrary 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, if the surface is not goodquality standard,There are many ways of ignition, such as arc, electric spark, flame, strong current, high-temperature furnace, electron beam, laser, high-temperature radiation, microwave, chemical furnace, etc.In the case of dynamic load, plastic design usually calculates the allowable stress according to the safety factor that the allowable stress is not less than the dynamic load and multiplied by the allowable stress. In the case of bending of an axis, it can be calculated by the formula a = W. replacing the calculated strength with plasticity can improve the bearing capacity of the member by %.QB square tube is a product appeared in recent years, which mainly has strict tolerance and roughness for the dimensions of inner hole and outer wall. Production process classification of large-diameter qb square tube large-diameter qb square tube is divided into hot-rolled seamless square tube, cold drawn seamless square tube, seamless square tube and qb square tube according to production process. Among them, qb square tube is divided into: (a) by process & mdash& mdash; Arc welded square pipe,MoitaPrice of galvanized steel, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Material classification of straight seam welded square pipe and spiral welded square pipe large diameter qb square pipe: plain carbon steel square pipe and low alloy square pipe. Ordinary carbon steel is divided into Q Q q SS, # steel, # steel, etc; Low alloy steels are divided into q Mn, Q, etc.Moita,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.If the re inspection results are unqualified (including the items whose preliminary inspection results are unqualified and re inspection is not allowed), the supplier can submit them for acceptance one by one; Or re conduct heat treatment (the number of RE heat treatment shall not exceed times), and propose acceptance with a new batch.The principle is similar to that of the plate rolling machine. The bending machine can determine a circle. Adjust the height to adjust the curvature.