Xiangyang medium thick wall rectangular tube manufacturer wholesale direct production
1. Solid bending: solid bending, which literally means that the bending is compacted, and the inner and outer rollers and the inner and outer walls of the tube blank are compacted in both directions during solid bending. 1) The advantage of real bending is small elasticity, accurate forming, and only accurate roll shape is required. The R of internal angle forming is relatively accurate. 2) The defect of real bending is tensile/thinning effect. 1、 The actual bending will produce tension at the bend, and the tensile effect will shorten the longitudinal length of the bending line; 2、 The metal at the solid bend will become thinner due to stretching. 2. Empty bending: empty bending is the bending moment formed by the one-way contact between the outer roll and the outer wall of the tube blank to bend the strip. Empty bending will cause the bending line to shrink, and the shrink effect will make the bending line longitudinally extend, and the metal at the bend will appear to accumulate and thicken, which is the shrink/thicken effect of empty bending. 1) The advantage of empty bending is that it can stop the bending of side length when the real bending cannot be stopped, such as the synchronous bending and finishing of the upper/side edges of square and rectangular tubes. Empty bending can also bend the inner corner with R<0.2t without breaking the pipe wall. 2) The defect of empty bending is that when the upper side/side side are synchronously empty bending, because the upper roll and the lower roll produce pressure at the same time, the forming force is easy to exceed the critical point, forming the edge instability concave, and also will affect the stable operation of the unit and the forming quality. This is also the different characteristics of square and round tubes during empty bending.
Xiangyang medium thick wall rectangular tube manufacturer wholesale direct production
1. Fake rectangular tubes are easy to fold. 2. The surface of fake and inferior rectangular tubes is often pitted. 3. The appearance of fake and inferior rectangular tubes is easy to produce scars. 4. The appearance of fake and inferior materials is easy to crack. 5. Fake rectangular tubes are easy to scratch. 6. The fake and inferior rectangular tube has no metallic luster and is light red. 7. The transverse reinforcement of fake and inferior rectangular tubes is thin and low, which often shows the phenomenon of being insufficient. 8. The cross section of the fake rectangular tube is oval. 9. The composition of steel is average, the tonnage of the cold shear is high, and the end face of the cutting head is smooth and uniform. 10. The material of fake and inferior rectangular tubes contains many impurities, and the density of steel is relatively small. 11. The inner diameter of fake and inferior rectangular tubes fluctuates greatly. 12. The trademark and printing of the tube are relatively standard. 13. The spacing of rectangular pipes with a diameter of more than 16 is more than IM. 14. The longitudinal reinforcement of deformed steel bars made of fake and inferior steel is often wavy.
Xiangyang medium thick wall rectangular tube manufacturer wholesale direct production
The manufacturing technology of fine steel pipes is very strict. Only a few steel pipe factories can meet the conditions for consumption of fine steel pipes, which leads to the appearance of fine steel pipes in the market, some of which are not really fine steel pipes. Therefore, when we purchase steel pipes, we should know some skills to distinguish fine steel pipes. But for ordinary steel pipes, it is indicated that they are not lubricated enough, and their toughness and torsional strength are not good enough. Once this steel pipe stops flaring or flattening, it is easy to show cracks. When these cracked steel pipes are used in machinery and equipment, they will present falling and broken residues. These residues will enter more and more delicate parts with the use of the equipment, which will affect the speed and progress of the equipment for a long time, presenting various equipment problems. If fine steel pipes are used, this phenomenon will be reduced in greater layers. Fine seamless steel pipe is a kind of high-precision steel pipe material after cold drawing or hot rolling. This allows the pipeline to be free from leakage under high pressure. Even after flaring, flattening and other operations, the pipeline will not show cracks. This ensures the normal operation of the equipment, speeds up the consumption efficiency and improves the overall interests. With the change of time, the supply and demand relationship of the market is also changing from time to time. This is why there are always some new products in the market. Because every industry hopes to have higher quality and higher performance products. In the steel pipe market, the speed of change will be even higher. Especially in recent years, the renewal rate of steel pipes has reached a peak. Under such a background, there are many steel pipes whose quality cannot keep up with this change, which have slowly disappeared. However, there are also some steel pipes that, depending on their quality and application performance, have opened up a larger market space, and fine steel pipes are one of them.
Xiangyang medium thick wall rectangular tube manufacturer wholesale direct production
(1) Alloy composition For seamless square tubes, elements 0, 10 and F are the main alloy elements that make the alloy have good pitting corrosion resistance. Other elements may also have corresponding effects. K and other elements will reduce the pitting corrosion resistance of seamless square tubes. It is certain that the effect of alloying elements on the pitting corrosion resistance of data can be summarized briefly into favorable effects. 13. The impact of 0 is variable. 3 is beneficial in solid solution, but it is harmful when it is precipitated as intermediate metal phase, 0 is good in solid solution, and it is harmful when it is precipitated as carbide, but it has slightly adverse effects. (2) The study on cold working of austenitic seamless square tubes shows that the number of etch pits on the surface of the specimen increases and the size of the etch pits decreases after cold working. This is due to the increase of dislocation density during cold processing. Dislocation exposed on the surface is easy to cause corrosion pits. Cold processing tends to increase pitting corrosion. (3) For a given alloy environment system, the element that determines the corrosion potential of alloy spots is the brightness of the data surface. In fact, it is meaningless to compare the corrosion tendency of stop points of alloys with different surface brightness. The influence of surface brightness on the pitting corrosion performance of seamless square tubes is shown in the figure. It indicates that in the same data environment system, if the surface brightness is different, the difference of pitting corrosion potential can be more than 14. (4) The oxide formed by heating of the seamless square tube in the air may have a serious impact on the pitting corrosion performance. The microstructure of hot-dip galvanized square tubes plays an important role in the pitting corrosion resistance of alloys. Various phases, such as sulfide inclusion and 3-ferrite. Phase, sensitized grain boundary and weld may have a decisive impact on the pitting corrosion resistance of steel, and they are all sensitive parts to pitting corrosion. For cast seamless square tubes with complex microstructure and martensite seamless square tubes with microstructure sensitive to heat treatment process, the relationship between pitting corrosion and constituent phases is closer. It is pointed out that the complex manganese sulfide inclusions are more sensitive to pitting corrosion. Therefore, the use of aluminum deoxidizer should be prevented when smelting seamless square tubes. (5) The oxide film produced by welding may be detrimental to the pitting corrosion resistance of the alloy in strong chloride solution. (6) The main function of passivation treatment is to dissolve the inclusions and infections on the surface of the seamless square tube to make it clean. It can also remove the manganese sulfide inclusions on the surface, which may become the source of pitting corrosion, thus improving the pitting corrosion resistance of the seamless square tube. It should be noted that the seamless square tube should be cleaned with sodium hydroxide solution after passivation treatment.
Xiangyang medium thick wall rectangular tube manufacturer wholesale direct production
Wall thickness grading of rectangular pipes - extra thick rectangular pipes, thick rectangular pipes, thin rectangular pipes. The thick wall rectangular pipe is a galvanized welded square pipe used for low pressure fluid escort, which is only used for ordinary low pressure fluid, mainly used for water, gas, oil, hot water or steam escort; Galvanized welded thick wall rectangular pipe for low pressure escort is mainly used to escort ordinary low pressure fluids such as water, gas, oil, hot water or steam. The surface of the square pipe adopts hot galvanizing or cold galvanizing anti-corrosion process. The rectangular thick wall mining infusion welding square tube is mainly used for mining air pressure welding, row welding, shaft drop welding, etc.
