High quality steel (P & le; .%, S & le; .%)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, 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.Maastricht,High strength structural steel with carbon content of .% - .%, adding main alloy elements such as manganese, silicon, vanadium, niobium and titanium; Its total alloy content is %. According to the strength, it is divided into four levels: , , plasticity and hardness discussed above are indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.Nieuwegein,Brinell hardness (HB), Rockwell hardness (HRC) and Vickers hardness (HV) are commonly used.For transportation: water supply, drainage, sewage treatment engineering, mud transportation, marine water transportation.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, 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, 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,MaastrichtHot dip galvanized rectangular square pipe, 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, 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 the steel pipe surface does not need to be coated with oil after being cleaned, 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, it can reflect that the square tube is good. On the contrary, if the surface is not good

For oil, the oil brush work shall be carried out in accordance with the requirements of the rule system, so as to ensure the oil brush and the oil in the correct position of the brush and avoid wrinkles.The general delivery length of square pipe is mm-mm, mostly mm and mm. The square tube is allowed to deliver short and non fixed length products not less than 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).Hardness QB square hardness is a pointer to measure the hardness and softness of metal materials. At present,For transportation: water supply, drainage, sewage treatment engineering, mud transportation, marine water transportation.The load of impact toughness acting on the parts at a great speed is called impact load. It is specialized in products and renewable resources. Its business includes: square tube, square tube, seamless square tube, galvanized square tube and galvanized tube. The ability of metal under impact load is called impact toughness.Precision pipe is a seamless pipe with high dimensional accuracy and good surface finish for mechanical structure and hydraulic equipment. The selection of precision seamless mechanical structure or hydraulic equipment can greatly save machining hours improve material rate and improve product quality. Seamless pipe can be divided into hot rolled pipe and cold rolled pipe according to different production

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.Statistics,B. low alloy structural steel C. ordinary structural steel and high-quality steel for specific purposes (including high-quality steel)The 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, and R and R can be equal or different.Maastricht,It should be noted that the position of the disc from the calibration line can be adjusted according to the reinforcement diameter, and R and R can be equal or different.Square tube production most square tube processing is square tube pressure processing, resulting in plastic deformation of the processed steel (billet ingot,MaastrichtJDG pipe galvanized, etc.). According to the square tube processing temperature, the square tube can be divided into cold processing and hot processing. The main processing of square tube includes: rolling: the gap (various shapes) between the square tube metal blank and the rotating roll , because of the compression of the roll, the material section is reduced and the length is increased. This is a common production method for producing square tubes. It is mainly used to produce square tube profiles, plates and tubes. It is divided into cold rolling and hot rolling.Brinell hardness (HB), Rockwell hardness (HRC) and Vickers hardness (HV) are commonly used.