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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,cork20 seamless pipe manufacturer, 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,corkQ235B longitudinal welded pipe manufacturer, 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, 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.Aiming at the connective tissue and texture produced in stainless steel plate Position and other crystal defects are generally removed by heat treatment processes such as quenching or quenching. The effect of quenching is to optimize the crystal, eliminate structural defects, reduce strength, and also conducive to cold drawing. In the production and manufacture of cold drawn alloy pipe, the formulation of appropriate annealing process is a necessary condition to ensure that the alloy pipe mechanism meets the standard and the commodity does not crack. If the manufacturer in order to better one sidedness, reduce the product cost and reduce the quenching process, it will eventually lead to bad harm to the product quality.cork,The allowable deviation of vertical installation of galvanized pipe is mm per meter, and the allowable deviation above m is no more than mm. The allowable deviation of horizontally installed pipes is mm per meter. Mixed pass system. According to the characteristics of rolling mills and products, in order to give full play to the advantages of their respective systems and overcome their disadvantages, mixed pass system is often adopted, that is, the combination of more than two systems. For example, straight leg cross rolling pass system is adopted for finished hole and front hole of finished product, and bent leg cross rolling system is adopted for other passes; or direct rolling system is adopted for rough rolling hole and straight rolling system is adopted for the last ~ finish rolling holes Leg oblique tie hole, etc.Stijena,The sodium cyanide passivation treatment of alloy pipe can be divided into four categories. Before passivation treatment, the surface of alloy pipe shall be clear of oil stains, pickled and passivated. Passivation treatment can be carried out only after the surface is cleaned, and the workpiece of alloy pipe products can be infiltrated into aqueous solution. The passivation treatment of the alloy tube in sodium cyanide transforms the surface layer into a very thin passivation treatment film, which determines that the color of the surface layer has no change before and after passivation treatment, and the reproducibility of the solution is good.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, the use of I-beam should be reasonably selected according to the mechanical properties, chemical properties, weldability and structural size of I-beam.→ wide flange and large lateral stiffness. Strong bending resistance.

Pass design According to the diameter of the pipe, the pipe with small diameter can only be welded on one side and the technician can drill into the pipe to weld on both sides. Single side welding requires the welder&#;s technology, which can be formed by welding two on one side. Through the steel ball test, it can ensure that the cross-sectional area passing capacity and weld formation meet the design requirements.Main uses: as a finished material, flat steel can be used to make hoop iron, tools and mechanical parts, and used as building frame structural parts and escalators in buildings. Flat steel is divided into two types according to its shape: plane spring flat steel and single-sided double groove spring flat steel. Hot rolled spring flat steel is mainly used to manufacture leaf springs for automobiles, tractors, railway transportation and other machinery.management,Defects of alloy pipe and solutions:Difference and application description between H-beam and I-beamUnder the action of thermal stress, the heart is pulled. At the end of cooling, because the final cooling volume shrinkage of the heart cannot be carried out freely,corkPrice of 12Cr1MoV alloy 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, 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, shape and chemical composition of the workpiece in the martensitic transformation zone.

X-ray or ultrasonic testing shall be carried out for repair welding of alloy pipe, dead end welding of strip steel and circumferential seam. For the spiral welding of steel for the transportation of flammable general liquids, yibai%sx ray or ultrasonic testing shall be carried out. For the spiral welding of alloy pipes for the transportation of water, wastewater, gas, heating steam and other general liquids, X-ray or ultrasonic testing sampling inspection (%) shall be carried out.analysis,GB No. I-beam is in height, in leg width and in waist thickness.According to the data information display information, there is an inseparable correlation between the annual real estate sales data information and the apparent consumption data information of galvanized pipe. From the consumption surface of the middle and lower reaches of galvanized pipe, decoration design, elevator car, handicrafts, household appliances and other industries are closely related to the situation of the real estate industry.Advantages of using I-beam: reduce maintenance cost, reduce downtime, improve equipment operation rate, reduce wear,When it is used for ground heating and hot spring transportation, it can meet the requirements of refrigeration and achieve the practical effect of less damage. It is applicable to water conservancy engineering, mining and other industries to meet the provisions of cold, cold and corrosion prevention. In addition the chemical raw material transmission pipeline has a wide indoor space.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.H-section steel is an economic section high-efficiency profile with more optimized section area distribution and more reasonable strength weight ratio. It is named because its section is the same as the English letter 'H'. There is no slope on the inner side of the two outer edges of H-section steel, which is straight. This makes the welding and splicing of H-section steel simpler than I-section steel, better mechanical properties per unit weight, and can save a lot of materials and construction time.