The alloy tube can be hardened by induction heating, so it has excellent rolling fatigue characteristics and corrosion resistance. Therefore, this kind of steel has been widely used as the material of rolling mill flap ball screw in rolling mill manufacturers. In addition to the excellent properties of cronidur steel, the modified LNs steel of case hardening steel also has the surface compressive stress characteristics obtained by heat treatment, and its application range is expected to be further expanded.Its heat sealing effect is remarkable. It can be directly buried immediately, which can not only save resources, but also reduce consumption, not occupy the natural environment, but also purify the environment. The transportation of gas can meet the requirements of long-distance transportation, prevent actual operation and maintenance, meet the requirements of thermal insulation and cold protection, reduce heating equipment, and reduce the construction cycle time of the project. On the whole, it is more convenient to use. It can also be used for the transportation of floor heating and hot springs.Gillard melena,Oxygen blowing welded pipe: it is used as steel blowing pipe. Generally small-diameter welded steel pipe is used. There are eight standards from / inch to inch. Made of , , , or q-q steel strip. In order to prevent corrosion, some are aluminized.Ways to obtain surface compressive stress characteristics of alloy tubesBan Phai, because the section size is relatively high and narrow, the moment of inertia of the two main axes of the section is quite different, so it can only be directly used for members bent in the plane of their web or form lattice stressed members. It is not suitable for axial compression members or members with bending perpendicular to the web plane, which makes it very limited in the scope of application. I-beam is widely used in buildings or other metal structures.During the heating and cooling process of structural welded pipe workpiece, due to the inconsistent cooling speed and time of surface layer and core layer, the temperature difference will be formed, resulting in uneven volume expansion and contraction, resulting in stress, namely thermal stress. Under the action of thermal stress, the starting temperature of the surface layer is lower than that of the core layer, and the shrinkage is greater than that of the core layer making the core layer stretch. At the end of cooling, the surface layer is compressed and the core is stretched because the cooling volume contraction of the core cannot be carried out freely. That is, under the action of thermal stress, the surface of the workpiece is compressed and the core is pulled. H-section steel is an economic section steel with better mechanical properties than I-section steel. It is named because its section shape is the same as the English letter 'H'. The flange of hot rolled H-beam is wider than that of I-beam, with large lateral stiffness and strong bending resistance. Under the same specification, H-beam is lighter than I-beam.equipment maintenance ,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, 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,Gillard melenaPrice of No. 20 seamless pipe, due to the change of microstructure during heat treatment,Gillard melenaPrice of 15CrMoG alloy pipe, 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, 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,Gillard melenaHow much is welded pipe per ton now, shape and chemical composition of the workpiece in the martensitic transformation zone.When selecting I-beam in structural design, reasonable I-beam shall be selected according to its mechanical properties, weldability and structural size.H-section steel

Heating surface pipes, economizers, superheaters, reheaters, pipes for petrochemical industry etc. for high-pressure boilers (working pressure is generally above MPa and working temperature is between ℃ ~ ℃)Where is it,The specification of I-beam is expressed in cm of waist width. For example, the waist width of No. I-beam is cm. The types of I-beam include hot-rolled ordinary I-beam Light I-beam and wide parallel leg I-beam (H-beam). The waist width of hot-rolled ordinary I-beam in China is ~ mm, expressed as No. ~ No., and the inclination of inner side wall of leg is : The pass system of rolled I-beam includes direct rolling pass system, cross rolling pass system and mixed pass system. In addition, I-beam can also adopt special rolling method.The pollution of the joint causes the welding cracking. The composite pipe welding is an accurate work. If it is not done well, it will not only waste resources, but also lead to work efficiency, rework and restart, and waste financial resources.Advantages of using I-beam: reduce maintenance cost, improve equipment operation rate reduce wear, H-section steel is an economic section steel with better mechanical properties than I-section steel. It is named because its section shape is the same as the English letter 'H'. The flange of hot rolled H-beam is wider than that of I-beam, with large lateral stiffness and strong bending resistance. Under the same specification, H-beam is lighter than I-beam.Nitriding: also known as nitriding, it is the process of penetrating nitrogen atoms into the surface layer of steel. At present, gas nitriding is widely used in the production of alloy steel pipe. Cross rolling pass system. This pass system refers to that the two open legs of the I-beam pass are not on the same side of the waist at the same time, and the waist has an included angle with the horizontal axis.