The surface of cold galvanized layer is smooth, dense and uniform. It has good mechanical properties and corrosion resistance. The consumption of hot-dip galvanized coating is between % - %. The galvanizing process is complex, but the thickness of single-sided coating, surface coating and double-sided coating is different, so the thin-walled pipe shall be galvanized. The zinc coating has strong protection and corrosion resistance.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.Sibiti,After the passivation treatment of alloy pipe, it is clearly proposed that water cleaning shall be carried out immediately after the aqueous solution, ~ times of water cleaning, and then chromic acid closed solution shall be carried out. Chromic acid solution must be carried out h after the subsequent water cleaning of metallographic structure and austenitic alloy pipe. Chromic acid aqueous solution (mass ratio) is % ~ %, the solution temperature is ~ ℃, and the solution time is min. Then dry.The utility model has the advantages that the axial force of the roll is small, the working inclined plane is not required, the pass occupies a small length of the roll body, and more passes can be matched under the condition of a certain length of the roll body.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 ℃ ~ ℃)

Judged as failing.Galvanized pipe is often seen in our daily life, especially in some construction sites. This product has the advantage of durability when used. It also has the characteristics of surface gloss uniform zinc layer and no missing plating. Moreover, the cost of hot-dip galvanizing for rust prevention is lower than that of other paint coatings. In addition, this product also has the characteristics of no dripping, strong adhesion breaking the clean Legion and strong corrosion resistance. Even if it is used in some places where the environment is not good, its service life is also very long, and it also has the characteristics of corrosion resistance. The standard anti rust thickness of hot-dip galvanizing can be maintained for more than years without repair. This is used in some suburban environments. However, in urban or offshore areas standard urban or offshore areas can be maintained for years without repair. The products produced by our company must meet these requirements. Friends who need to order can call us directly.The shape of small longitudinal crack on the surface of alloy pipe is less than mm The overall width is less than mm The depth is lower than .mm.Good reputation,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.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,Republic of Bosnia and MontenegroHow much is welded pipe, 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,Republic of Bosnia and MontenegroHot dip galvanized welded pipe manufacturer, 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. Frame line crack

H-beam is a widely used profile in steel structure buildings. It is different from I-beam. The first is the flange, and the second is that the inner surface of the flange has no inclination, and the upper and lower surfaces are parallel. The section characteristics of H-beam are obviously better than those of traditional I-beam, channel steel and angle steel.Which one is betterI-beam is divided into ordinary I-beam and light I-beam. The specification of hot rolled ordinary I-beam is -#. The specification of hot-rolled flexible I-beam supplied through agreement between the supplier and the buyer is -#. I-beam is mainly used in building structure,Republic of Bosnia and MontenegroLongitudinal welded pipe manufacturer, vehicle manufacturing, other industrial structures and fixed panels and cabinets. I-beam is often used together with I-beam. Pickling stainless steel pipe. When removing grease, rust prevention, spot welding, free iron and other dirt, prevent metal corrosion and hydrogen embrittlement and inhibit fog production.→ under the same section load, the weight of hot-rolled H steel structure is reduced by % - % compared with the traditional structure.Republic of Bosnia and Montenegro,Whether I-section steel is ordinary or light, 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.Greatly reduce the environmental pollution caused by abrasion, damage and blanking, and increase the labor cost of material cleaningPlan scheme : high carbon steel with carbon content exceeding .% and alloy pipe with chromium content not less than %