TezinetsCold r
San-RamonDN25 there are various forms of heat exchangers petrochemical and other occupations, but the conventional heat exchangers have many disadvantages, such as poor heat exchange, difficult cleaning, large dust thermal resistance and so on, which can not meet the needs of production customers. The square tube heat exchanger based on square tube throat has the advantages of excellent heat exchange, easy cleaning, small dust thermal resistance and compact structure.
Square pipe is a square steel pipe cold drawn from seamless steel pipe, which is not a straight q355b square pipe, and q355b square pipe,Tezinets46 galvanized pipe, also known as welded pipe, is a square pipe welded by steel plate or strip steel after crimping. Q355b square tube has the advantages of simple production process, high production efficiency, many varieties and specifications and less equipment. The commonly used materials are Q235A and Q235C.
Tezinets.Square tube, modified square tube, square tube Q345B 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.
Chemical polishing: less investment in processing equipment, high speed,TezinetsHot dip galvanized rectangular tube, high efficiency and good durability. Its defects are poor brightness, gas overflow, demand for ventilation equipment and difficult heating. It is suitable for processing small batch of disordered parts and products with low brightness demand for small parts.
.The advantage of empty bending is that it can bend the side length when the real bending cannot be carried out, such as synchronous bending and finishing of the upper side and side of q355b square tube. Empty bending can also bend the inner corner of r0.2t without fracture of pipe wall. The disadvantage of empty bending is that when the upper side and side are synchronous empty bending, due to the pressure generated by the upper roll and the lower roll at the same time, the forming force is easy to exceed the critical point, resulting in edge instability and concave, and will also affect the stable operation of the unit and forming quality. This is also the different characteristics of q355b square tube and round tube empty bending.
Now, with the continuous development of q355b square tube, its use is becoming more and more extensive, and the technology is also following up. Therefore, we still look forward to the development of q355b square tube in the future.
In the process of square pipe, we will conduct a variety of tests on it to ensure that the square pipe can be better used in practice. In order to make better use of large-diameter steel pipe, we will continue to innovate. Let's introduce the main elements contained in the lower pipe. For the martensitic chromium square tube, the main elements affecting the are chromium, carbon and molybdenum; For Martensitic chromium nickel square tube, the main influencing elements are nickel, aluminum, cobalt, nitrogen and titanium.
When cutting the square tube, there will be deformation, uneven incision and crack of the incision. What should we pay attention to when cutting the square tube and how to operate it? Today, I will introduce some problems that should be paid attention to when cutting the square tube. If the correct operation will make the square tube cutting work very smooth, please use a rag or cloth to clean the oil on the surface of the square tube Sundries or soil shall be completely clean.
Reinforcing phases such as reinforcing particles, oil, natural gas, heating and other pipelines.
market price.However, there is a large rate of end in the application of steel pipe, which is mainly due to the trouble of internal and external treatment. The first question is very crucial, and the external quality is good or bad
The advantage of empty bending is that it can bend the side length when the real bending cannot be carried out, such as synchronous bending and finishing of the upper side and side of q355b square tube. Empty bending can also bend the inner corner of r0.2t without fracture of pipe wall. The disadvantage of empty bending is that when the upper side and side are synchronous empty bending, due to the pressure generated by the upper roll and the lower roll at the same time, the forming force is easy to exceed the critical point, resulting in edge instability and concave, and will also affect the stable operation of the unit and forming quality. This is also the different characteristics of q355b square tube and round tube empty bending.
Mechanical properties of seamless q355b square tube: tensile strength & sigma; b (MPa)：≥ 980 yield strength & sigma; s (MPa)：≥ 835 elongation & Delta; 5(%)：≥ 12 reduction of area & psi; (%)：≥ 40 impact absorption energy (impact value) (aku2j): & Ge; 39 the products produced by the more complex technology are exquisite. At present,TezinetsPrice of galvanized square pipe, Fangguan is highly praised by the public in the market. What is important is that there is a good guarantee in terms of quality. Therefore, whether Fangguan can obtain such a high market evaluation depends on the complex technology of Fangguan.
To sum up, improving the quality level of square tube is the key to ensure the service life of die. Therefore, the quality level of square tube, including surface quality and internal quality, should be improved as much as possible by using more mature process measures.
A complete range of products.Upper yield point (& sigma; Su): the large stress before the yield of the sample occurs and the stress decreases for the first time; Lower yield point (& sigma; SL): the small stress in the yield stage when the initial instantaneous effect is not considered.
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.
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, if & psi; If n is too small, the deformation stress will increase sharply, resulting in the fracture of the bottom of the drawing part.
Tezinets.How to reduce the amount of oxide scale is the key to the heating operation of seamless square tube. Especially when it's hot. Starting from the service life of tools and the surface quality of pipes, the requirements are more stringent. For example hot furnaces are divided into heating furnace and reheating furnace according to their functions; The former is used to heat the blank from normal temperature to processing temperature; The latter is used to reheat the blank to the necessary processing temperature during processing.
All seamless q355b square tubes shall be tested for mechanical properties. Mechanical property tests are mainly divided into two categories: tensile test and hardness test.
Galvanized q355b square pipe for low pressure fluid transmission, gas Standard No.: gbt3092-2008. The representative material is the same as above. It is mainly used to transport low pressure fluids such as water, air, oil and heating hot water or steam. The surface of square pipe adopts hot galvanizing or cold galvanizing process.