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, 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, 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,Lemni kuvolchaHot dip galvanized square pipe Market, 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,Lemni kuvolcha6-inch galvanized square pipe, 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,Lemni kuvolchaDN65 galvanized round pipe, 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, all kinds of square tubes, rectangular tubes, seamless 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 goodFerrous metals refer to iron and iron alloys. Such as steel, pig iron, ferroalloy, cast iron, etc. Steel and pig iron are alloys based on iron square tube and carbon as the main added element, collectively referred to as iron carbon alloy.Lemni kuvolcha,Shot blasting is a high-speed rotating impeller that throws small steel shot or small iron shot out and hits the surface of the square tube at high speed, so the oxide layer on the surface of the square tube can be removed. At the same time, the steel shot or iron shot impacts the surface of the square tube at high speed, resulting in lattice distortion and deformation on the surface of the square tube, increasing the surface hardness, which is the main reason for the surface deformation of the square tubeComprehensive classification ordinary steel A. carbon structural steel: (a) Q (b) Q (b); (c) Q( C)； (d) Q( B)； (e) Q.Maldonado,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.Square tubes are classified by forming: forged steel; Cast steel; Hot rolled steel; Cold drawn steel.Engaged in square tube, square rectangular tube, seamless square tube, galvanized square tube, galvanized tube, old brand, 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, air gas, oil and heating hot water or steam, and its purpose is limited to general low pressure fluid.

B. low alloy structural steel C. ordinary structural steel and high-quality steel for specific purposes (including high-quality steel)The selected punch and die fillet has a great relationship with the size and distribution of stress.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.manufacturer,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, seamless square tubes, galvanized square tubes, 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.The principle of straightening machine is that a disc is divided into two sides to clamp round steel straight lines. Professional square tube, square rectangular tube, seamless square tube, galvanized square tube, galvanized tube, high price, service, on-site settlement, honest operation! The edge is one with radius r and the other outer edge must be two equal diameters with radius R. The diameter of the reinforcement to be straightened is D, and the center distance between them is adjusted to R + R + D.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, etc. in the warehouse, 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, 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, sulfur s, phosphorus P and chromium CR.

Derusting: This is an important process for galvanized square pipes and components before coating, and it is the key to the quality of galvanized square pipes. Thorough derusting can improve the adhesion of antirust paint and prolong the service life of galvanized square pipe.OK or not?,After cold drawing and aging treatment, the tensile ultimate strength is also increased, and the plasticity continues to decrease. Due to the reduction of internal stress during aging, the modulus can be basically restored. According to this principle, cold drawing or cold drawing of reinforcement or low carbon steel wire rod is often carried out on site or prefabricated component factory, so as to improve yield strength and save steel.× × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × Standard treatment of steps for preventing oxidation of ~ square tube square tube is a kind of metallic maintenance. The main components are iron and zinc. It is easy to have redox reaction in the air. Once the reaction occurs, many new substances have taken place, and the original characteristics have changed. However in order to maintain the original relevant characteristics, anti-oxidation treatment is required. The direct reason is to prevent the square tube from reacting with the oxygen in the air, which is the way to isolate the oxygen in the air. Today, this article makes a relatively standardized treatment on the relevant steps to prevent oxidation of square tubes: the key depends on what kind of antirust paint you use. . If you use epoxy zinc rich or iron rich antirust paint, you can directly spray fluorocarbon paint on it; if alkyd antirust or red lead is used, it shall be cleaned with paint remover and sprayed with epoxy zinc rich or iron rich antirust paint again before fluorocarbon paint can be sprayed.B. converter steel: (a) acid converter steel; (b) Basic converter steel. Or (a) bottom blown converter steel; (b) Side blown converter steel; (c) Top blown converter steel.Lemni kuvolcha,After cold drawing and aging treatment, the yield point is improved, and the plasticity continues to decrease. Due to the reduction of internal stress during aging, the modulus can be basically restored. According to this principle, cold drawing or cold drawing of reinforcement or low carbon steel wire rod is often carried out on site or prefabricated component factory, so as to improve yield strength and save steel.Steel used & mdash& mdash; Such as bridge steel, ship steel, boiler steel, agricultural machinery steel, etc.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.