B. low alloy structural steel C. ordinary structural steel and high-quality steel for specific purposes (including high-quality steel)Superior square tubular steel (both P and s ≤ .%)Bouquet cross,The researcher's test before using the strip thinning drawing also confirmed that using the strip thinning drawing can greatly reduce the large value of tangential residual stress of the drawn parts and effectively prevent the occurrence of longitudinal cracking. According to different deformation degree and original sheet thickness, the appropriate thinning coefficient & psi is selected; N (generally .t ~ .t), if & psi; If n is too small, the deformation stress will increase sharply, resulting in the fracture of the bottom of the drawing part.Alloy steel: A. low alloy steel (total alloy element content & le; %); b. Medium alloy steel (total alloy element content > ~ %); c. High alloy steel (total alloy element content > %).Pontinha,If there is only a single plane weld, the step-by-step back welding shall be adopted from the middle, that is, the arc of the section weld shall be terminated at the section arc.. 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, the oil brush work shall be carried out in accordance with the requirements of the rule system, 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, 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, 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, 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, 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,Bouquet crossSeamless galvanized square pipe, 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, thin-walled pipe alloy steel sheet, 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, 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 goodThe purpose of heat is to prevent the generation of cold cracks. Cold crack is directly related to carbon equivalent. Therefore, it is necessary to distinguish the carbon equivalent of the qb square tube, and the carbon equivalent of the qb square tube is the same. If the carbon equivalent of Q is less than .%, it can be said that the weldability is OK. Generally speaking, the cold crack increases when the carbon equivalent is .%.Tool derusting mainly uses tools such as steel wire brush to polish the surface of square pipe, which can remove loose or oxidized scale, rust, welding slag, etc. The derusting of manual tools can reach grade SA and that of power tools can reach grade SA. If the square pipe surface is firmly attached with iron oxide scale, the derusting effect of tools is not ideal and can not reach the anchor depth required by construction.production,Due to the increase of square tube production, there are more and more fake and shoddy square tubes in the market. How to distinguish the fake and shoddy square tubes? Let me teach you some points to distinguish the fake and shoddy square tubes.B. spring steel C. bearing steel tool steel: A. carbon tool steel; b. Alloy tool steel; c. High speed tool steel.The appearance of fake and inferior square tubes often has pitting. Pockmarked surface is an irregular uneven defect on the surface of square lead pipe due to serious wear of rolling groove. Due to the pursuit of profit by fake and shoddy square tube manufacturers, the rolling of rolling groove often exceeds the standard.

Square tube heating process square tube calculates the chip thickness of workpiece. After each regrinding, the service life of the saw blade. Regrinding times of the saw blade. When the saw blade is replaced, the main drive AC motor spindle rotates stepless speed change AC motor feed capacity stepless speed change feed fast return to a constant value center system brush device hydraulic saw cutting system system system represents the quality RA flatness, large burr height cutting Chip length tolerance dimension: width and length . ~ .mm ~ m ~ ~ min kW ~ rpm ( kw ~ mmmin mmmin .kw .kw & times; kW S & mu; m . mm & plusmn; mm about mm about mm about mm high. The total weight of each billet square tube is seconds (including, pipe blank cutting,Bouquet crossHow much is a ton of galvanized square tube, saw blade return, opening device, pipe blank discharge, head and tail cutting time, but excluding pipe blank transportation time). The large production capacity of the three saws is T / A. the pipe blank saw has a special reversing device (hydraulic servo device) to reduce vibration and improve the service life of the saw (only during feeding). The sawing machine has two devices distributed at the inlet and outlet (the input area is supported by roller table to ensure the bending of billet) The inlet end after sawing. Open it to ensure that the saw blade does not contact the blank when it returns. & mdash; feed saw gear & mdash; saw gear vibration reduction, which is composed of a fixed gear vibration reduction, as a movable vibration reduction to avoid the axial of the saw blade. & mdash; brush and sweep device & mdash; a driving brush and sweep device is installed at the bottom of the saw blade to clean the iron filings on the teeth and will not affect the service life of the saw blade. &Mdash; saw blade. In order to improve the service life of the saw blade a small amount of high load agent container is atomized by air and poured on the saw blade without residue. & mdash; saw blade cooling device. A special nozzle is used to spray cold air at - oC on the saw blade. The cut-off blank is transferred to the buffer chain in front of the loader after passing through the outlet roller table and weighing device (Note: # before sawing, and after weighing there is a feeding bench for single size billets that need to be cut, there is a feeding bench for returned billets). The buffer transfer chain transports the billets to the lower roller table of the loader. The billets are turned over from the chain to the roller table by the turnover hook. The weighed qualified billets are loaded into the annular furnace by the loader, and the weighed unqualified billets are transported from the roller table to the removal bench for removal.Where can I find it?,Improve the positioning and pre bending steps, if necessary, to ensure that the web hunting problem does not occur when pressing parts. Change the shape of the surface pressure of the material to ensure the quality of the parts and avoid the non movement of the surface shape of the roll gap, resulting in uneven walking feeding.Square tube has good machinability,Bouquet crossPrice of 80% galvanized square pipe, good cold deformation plasticity and weldability; In addition, the toughness of steel does not decrease much during heat treatment, especially when water quenching; However, this steel has great resistance to white spots, temper brittleness and overheating during heat treatment.Square tubes have different functions and different characteristics. Square tubes of various specifications, square rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes are welcome to waste merchants, industries, enterprises and power departments to visit and negotiate! Oxidation will also occur on the surface of square tubes after long-term use. What should we do if oxidation occurs? Let me give you a detailed introduction on how to remove square tubes Oxide scale.Bouquet cross,The reason why it is divided into two types is that chemical cleaning can only clean the surface very thoroughly, and it is difficult to achieve the desired results in some fine cracks.According to smelting classification and furnace type, A. open hearth steel: (a) acid open hearth steel; (b) Alkaline open hearth steel.Engaged in square tube, square rectangular tube, seamless square tube, galvanized square tube, galvanized tube, price advantage and quality guarantee! However, the Demander shall cut off the interface pipe when using it. The weight of short length and non fixed length products shall not exceed % of the total delivery. For qb square pipe with theoretical weight greater than kgm, it shall not exceed % of the total delivery. The bending degree of qb square pipe shall not be greater than mm per meter, and the total bending degree shall not be greater than .% of the total length. Galvanized qb square pipe for low-pressure fluid transmission, with standard number of gbt-. Representative materials: QA, qbqb, etc. It is mainly used for conveying water, gas, air, oil and heating hot water or steam, and its purpose is limited to general low pressure fluid.