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, acid, alkali, salt and atmospheric environment,Manzanillo40Cr large diameter alloy pipe,ManzanilloHow much is cold drawn welded pipe, high temperature, impact and fatigue, does not need regular maintenance,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.Determined by the shape, the section modulus, moment of inertia and corresponding strength of I-beam are obviously better than those of ordinary I-beam with the same single weight. When used in metal structures with different requirements, it shows its superior performance in bearing bending moment, pressure load and eccentric load. Compared with ordinary I-beam, it can greatly improve the bearing capacity and save metal by % ~ %.Greatly reduce the environmental pollution caused by abrasion, damage and blanking, and increase the labor cost of material cleaning

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.Third between the flange on the inner side of the sidewalk beam and the old bridge deck, the widening part of the bridge deck is poured with concrete, and the concrete of the bridge deck pavement is poured at the same time to form a carriageway. The reinforcement mesh is set on the bridge deck pavement and the widening part of the bridge deck to strengthen the overall performance. Fourth, the bridge deck expansion joint is set at the center of the cantilever beam top, and the carriageway pavement is extended and erected on the cantilever beam.Pass designHonesty is the foundation,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.After isothermal quenching treatment, the modified LNs steel of case hardening steel also has the surface compressive stress characteristics obtained by heat treatment.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.

I-beam is mainly used in building structure, curtain wall engineering, mechanical equipment and vehicle manufacturing.build,The utility model has the advantages that the axial force of the roll is small, the axial movement is small, and the working slope is not required,The reinforcement mesh of the maintenance platform has the characteristics of extensive application beautiful style, convenient installation and durability, Skirting plate (edge guard plate), checkered plate guard plate, installation of connectors and other accessories can be added around. The reinforcement mesh is suitable for the reinforcement mesh manufactured in the factory and welded with cold-rolled ribbed reinforcement or cold-rolled smooth round reinforcement. The welded reinforcement mesh for reinforced concrete is a good and efficient material for concrete distribution. Flat steel with different specifications can be used for edge wrapping, Or wrap edges with angle steel, channel steel, square tube, etc; Handles and hinges can also be installed on the reinforcement mesh that needs to be moved or opened frequently.Generally, the process of pickling and passivation will be carried out for alloy pipes, but the alloy pipes after pickling and passivation are very easy to rust. Therefore, the way to find a solution to wiredrawing corrosion is 'grinding and polishing'. Due to grinding and polishing, there is no harm to carry out hot galvanizing in the middle and later stage.Manzanillo,Defects of alloy pipe and solutions: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,Manzanillo12Cr1MoV alloy pipe, 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. Peak crack