Welded steel pipes need to be processed through various processes before application. The heat treatment of welded steel pipes is a very important link in the processing of welded steel pipes. Hot working is a metal hot working process in which metal materials are heated, insulated and cooled in a certain medium, and their metal properties are controlled by changing the metallographic structure on the surface or inside of the material. During the heating and cooling process of structural welded steel pipe workpiece, due to the inconsistency of cooling speed and time between the surface and the core, the temperature difference will be formed, which will lead to uneven volume expansion and contraction and produce stress, that is, thermal stress. Small longitudinal crackjeremy ,Galvanized pipe: the hot-dip galvanized pipe base plate and molten electroplating solution are combined physically and chemically to form a dense corrosion-resistant structure of zinc iron alloy layer. The alloy layer is integrated with the pure zinc layer and the steel pipe substrate. Therefore, it has strong corrosion resistance.I-beam is a kind of economical section steel with better section mechanical properties. Its characteristics are as follows:Samara,Alloy pipe is a very important way and type of seamless steel pipe. Its use is relatively common. It is widely used in various engineering projects, house construction and building decoration. Its fracture will always be found in the production, manufacturing and key marketing of alloy pipe, That is, many stages of production and processing are not done well. Another is that the seasoning is not enough and the proportion of chemical molecules is wrong. There are all reasons.Under the action of thermal stress, because the initial temperature of the surface layer is lower than that of the heart and the shrinkage is greater than that of the heart, the heart is pulled. At the end of cooling, because the final cooling volume shrinkage of the heart cannot be carried out freely,jeremy How many inches is the 219 seamless pipe, the surface layer is compressed and the heart is pulled. That is, under the action of thermal stress, the surface of the workpiece is finally compressed and the center is pulled. This phenomenon is affected by factors such as cooling rate, material composition and heat treatment process. The faster the cooling rate, the higher the carbon content and alloy composition, the greater the uneven plastic deformation caused by thermal stress during cooling, and the greater the final residual stress. On the other hand, due to the change of microstructure during heat treatment, i.e. the transformation from austenite to martensite, the increase of specific volume will be accompanied by the expansion of workpiece volume, and each part of workpiece will undergo phase transformation successively,jeremy 1Cr5Mo thick wall alloy pipe,jeremy 40Cr seamless alloy pipe, resulting in inconsistent volume growth and structural stress. The final result of the change of tissue stress is the tensile stress on the surface and the compressive stress in the center, which is just opposite to the thermal stress. The microstructure stress is related to the cooling rate, shape and chemical composition of the workpiece in the martensitic transformation zone.According to the theory of steel structure, the I-beam flange should be stressed, that is, the I-beam should be standing rather than lying down.

I-beam is widely used in buildings or other metal structures.Classification by use Hot hole breaking cold rolling method. This method is dominated by expansion and expands vertical sliding and skew rolling. The former one is mainly cold rolling by relatively limited mandrel mill, cold rolling by few station mandrel mill, cold rolling by three high limited mandrel mill and cold rolling by fluctuating mandrel mill. In this way, low metal material consumption, excellent product quality and excellent automatic control system are more and more widely used. The competitive advantage of the latter one is low cost and short whole process. It is suitable for the processing and manufacturing of CrMoG alloy pipes with large quantities, small types, multi specifications and high precision. Therefore it is widely usedoriginal,The crack mainly occurs at -mm from the edge of the alloy pipe. The shape is several parallel vertical cracks of different sizes. The regularity is that the thicker the specification and model of the alloy pipe is The wider the width, the more serious the disadvantages.The import and export order of I-beam is generally based on the specifications required in use after determining the corresponding carbon structure steel (or low alloy steel) steel grade. Except for the specification number, I-beam has no specific composition and performance series.The crack mainly occurs at -mm from the edge of the alloy pipe. The shape is several parallel vertical cracks of different sizes. The regularity is that the thicker the specification and model of the alloy pipe is The wider the width the more serious the disadvantages.

All the cracks occur at -mm away from the edge below the alloy pipe, and the macroeconomic orientation is vertical to the cold rolling orientation, showing a 'high mountain' shape.Industry management,It is often asked that the shape of I-beam is similar to that of H-beam. What is the difference between them? Many people can&#;t explain it in detail. Here is a detailed answer for you: many people think that I-beam is a domestic name and H-beam is a foreign name. In fact, this cognition is wrong. H-beam and I-beam are different in shape!The monthly summary of the real estate industry shows that there is a significant positive correlation between the market sales and the long-term trend of the apparent consumption of galvanized pipe, but there will also be a backwardness of the market in a special stage, there will be a rapid decline in the moving average of the apparent consumption of galvanized pipe, welded steel pipe and so on.Some applications of I-beam:jeremy ,The section of I-beam has good straight pressure and tensile resistance, but the section size cannot resist torsion because the wing plate is too narrow. On the contrary, H steel has its own advantages and disadvantages.Because the section size of ordinary I-beam and light I-beam is relatively large and narrow, the moment of inertia of the two main shafts on the section is quite different which limits its application range. I-beam shall be selected according to the requirements of design drawings. In the structural design, chemical properties weldability and structural size of I-beam.I-beam, whether ordinary or light, can only be directly used for bending members or lattice members on its Web because of its large and narrow section size and large moment of inertia difference between the two main axes on the section. It is not suitable for axial compression members and flexural members perpendicular to the web plane