Heating surface tubes for low and medium pressure boilers (working pressure is generally not greater than MPA and working temperature is below ℃);I-beam can only be used for beam, while H-beam can be used for load-bearing column of structure.Jonkiel, Carbon: the higher the carbon content, the higher the hardness of steel, but the worse its plasticity and toughnessI-beam can be divided into four types according to shape: cold-formed equal edge I-beam, cold-formed unequal edge I-beam, cold-formed inner crimping I-beam and cold-formed outer crimping I-beam.Lumia,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, due to the change of microstructure during heat treatment, 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.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,JonkielHigh pressure alloy pipe 12Cr1MoVG, 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.Generally, the common ones are high temperature passivation or sodium cyanide passivation.

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.Galvanized pipe is a layer of galvanized ordinary steel. This is a layer and is a great anti-corrosion protection.The key purpose of grinding and polishing alloy pipe is to moisten the surface, and the relevant limit accuracy or appearance change is not easy to change.ranking, Hot push hole diameter. More sensitive applications and facilities of such methods require simplicity, low cost, easy maintenance, durable economic development and convenient product specification transformation. For example, the production of large diameter must be grooved pipe, elbow and similar products. You only need to add some spare parts. The expansion method of hot push can be used to process and manufacture large-diameter, thick wall and thin alloy steel pipes, and can not exceed the working capacity of thick wall pipes of machinery and equipment.Heating surface tubes for low and medium pressure boilers (working pressure is generally not greater than MPA and working temperature is below ℃);Dehydrogenation solution: the alloy pipe shall be dehydrogenated after passivation treatment to avoid alkali embrittlement

Carburizing: carburizing is the process of penetrating carbon atoms into the surface layer of steel. It also makes the low-carbon steel workpiece have the surface layer of high-carbon steel, and then after quenching and low-temperature tempering, the part of the workpiece can maintain the toughness and plasticity of low-carbon steel.Installation material list, small internal stress and no scratch on the surface. The alloy pipe produced and processed has higher coordination ability in the scope of size, specification and model of diameter and wall thickness, especially in the production and manufacturing of steel structure design grade thick wall pipe, especially medium diameter small thick wall pipe, which has incomparable advantages of other processing technologies, and can meet a large number of customer regulations on the specification and model of alloy pipe.Recently, the price of zinc has been falling continuously. The key reason lies in the soft skin of galvanized pipe consumption and the slow start of production and marketing rate of manufacturing industries in the middle and lower reaches after the Spring Festival. The disadvantage of zinc price has long been far beyond the level of cyclical factors. The main performance of no prosperity in the hot season is whether the market situation in the off peak season will become a more worried problem in the galvanized pipe sales market.I-beam, also known as steel beam, is a long strip of steel with I-shaped section. I-beam is divided into ordinary I-beam and light I-beam. It is a section steel with I-type section shape.Jonkiel,According to the theory of steel structure,JonkielHow much is welded pipe per ton now,JonkielHow much is 80 galvanized pipe per meter, the I-beam flange should be stressed, that is the I-beam should be standing rather than lying down.Plan scheme : Martensitic chromium alloy pipe and chromium alloy pipe with Cr composition exceeding %, without high carbon steel and high chromium alloy pipe. The aqueous solution contains % sodium cyanide % ~ % (volume ratio) the solution temperature is ~ ℃, and the solution time is min.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, 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, 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.