Stainless steel qb square pipe for mechanical structure， Standard No.: gbt-. Representative material Cr cr crni CrNi crninb， etc. It is mainly used for machinery， automobile， bicycle， furniture，Square rectangular tube hotel and restaurant decoration and other mechanical parts and structural parts.
8Requirements for samples samples can be taken from metal pipes with qualified appearance. Generally，Galvanized square pipe price meterAccuracy analysis of sawing is adopted.
tSquare tube for automobile half shaft sleeve (gb-) is a high-quality carbon structural steel and alloy structural steel hot-rolled square tube for automobile half shaft sleeve and drive axle housing.
High hardness square tubes mainly bear fatigue load so they must have high hardness. Therefore， quenching， surface quenching or chemical heat treatment shall be carried out， followed by low-temperature tempering treatment.
ABatty KentAccording to the welding specification， process test and process analysis， it is determined that the butt weld of QB square pipe adopts double-layer CO gas shielded welding. HMnSiA， mm welding wire for welding material; The shielding gas is pure CO gas. The welding current of layer weld is ~ A， and that of the second layer is ~ A; The arc voltage is ~ V. The process requirement is that the layer weld must be fully welded to ensure good back forming; The welding current， arc voltage，Square rectangular tube wire feeding speed and welding speed can be adjusted according to the equipment model.
KvThe selected punch and die fillet has a great relationship with the size and distribution of stress. Large fillet radius
There are many forms of heating furnace， but the ring heating furnace is mainly used. The heating furnace has an annular furnace bottom， which can rotate slowly， the blank is loaded along the diameter direction of the furnace bottom from the inlet， and can be heated and homogenized to the specified temperature when it is used at the outlet. The production process of seamless square tube is relatively slow and the heating operation especially needs patience. Because if the heating operation is not standardized， folding and eccentricity on the inner or outer surface of the tube blank will only produce waste products and defective products.
According to the welding specification， process test and process analysis， it is determined that the butt weld of QB square pipe adopts double-layer CO gas shielded welding. HMnSiA， mm welding wire for welding material; The shielding gas is pure CO gas. The welding current of layer weld is ~ A， arc voltage，Square rectangular tube wire feeding speed and welding speed can be adjusted according to the equipment model.
sAccording to metallographic classification， the annealed state of square tube: A. hypoeutectoid steel (ferrite + pearlite); b. Eutectoid steel (pearlite); c. Steel precipitation through a common square tube (pearlite + cementite); d. Ledeburite steel (pearlite + cementite).
TThe common surface treatment of square pipe includes surface treatment，Galvanized square pipe price meterAccuracy analysis of chemical treatment， shot blasting treatment， manual mechanical treatment and flame treatment. The treated will be separated. ~ Mpa compressed air entrains abrasives， and the nozzle sprays to the steel surface at high speed. The impact and friction of abrasives remove the oxide scale， rust and dirt on the steel surface， and make the steel surface reach a certain roughness.
YofferBefore square tube forming， the strip steel shall be leveled trimmed， planed，Galvanized pipe_ Galvanized square pipe_ Seamless steel pipe_ Square tube - Wuxi Jiahang surface cleaned， transported and pre bent.
jKSquare pipe is an important pipe. Its application in various fields has different performance. According to its different performance， the protective layer of seamless qb square tube can be chiseled and measured.
The general delivery length of qb square pipe is mm-mm， mostly mm and mm. Qb square tube is allowed to deliver short and non fixed length products not less than mm， or in the form of interface tube， but the Demander shall cut off the interface tube when using it. The weight of short length and non fixed length products shall not exceed % of the total delivery. For qb square tube with theoretical weight greater than kgm， it shall not exceed % of the total delivery. The bending degree of qb square tube shall not be greater than mm per meter， and the total bending degree shall not be greater than .% of the total length. The square tube is classified according to the production process: hot rolled seamless square tube， cold drawn seamless square tube， seamless square tube and square tube.
Market trendmThe level of R-angle square tube is generally - times of the wall thickness. R-angle square tube of the size required by customers can also be produced according to the needs of customers; Square tube is a kind of long steel with hollow section and no joints around. It is a square tube formed by four sides of seamless tube mold. Square tube has hollow section. It is specialized in selling square tube， square rectangular tube， seamless square tube， galvanized square tube， galvanized tube， strict testing and quality assurance. In the process of preferential activities， welcome to consult. It is widely used as a pipeline for conveying fluid. It is mainly used in conveying， hydraulic support and mechanical structure， Medium and low pressure， high pressure boiler tubes， heat exchange tubes， gas， which can be regarded as DEG from round tube to square tube; To & deg; The bending deformation of angle， so the deformation angle & theta; It can accurately reflect the deformation degree of corners and edges. In the design process， considering the influence of dimensional accuracy and metal work hardening， the distribution of deformation angle is usually larger at the beginning and middle passes， and then gradually decreases. In the pass formed directly by arc intersection， the fillet part of the pipe blank cannot be filled with the pass， so the pass perimeter is different from that of the pipe blank. In order to ensure the dimensional accuracy， the fillet part of the pass needs to be corrected and calculated. Therefore， this method has higher design accuracy than other methods. However， due to the large amount of iterative calculation， this method is more suitable for pass design by computer. If you use a frame that deforms both horizontally and vertically， you can directly use the deformation angle & theta; Pass design.
Preheating must be carried out before heat treatment of qb square tube， so as to better ensure that there will be no many problems in the whole heat treatment process of qb square tube， and the quality of qb square tube will also be well guaranteed.
eExcept for the thickening of wall thickness， the corner size and edge flatness of square pipe reach or even exceed that of resistance welding cold forming
wGAfter aluminum deoxidation in molten steel， & omega; When (ALS) is .% ~ .%， calcium treatment can achieve better effect on the denaturation of Al.
It is learned from that when degreasing the square pipe， if there is dirt on the outer surface of the steel pipe， it can be washed with purified water and dried naturally， then soaked with degreasing agent with a dry cloth to remove the oil and then dried in the open air. When degreasing the inner surface of the opposite pipe， placed in a flat and clean place or on a workbench with sleepers for -min the end of the pipe can be tightly blocked with a wooden plug or closed with other. The degreasing solvent with the volume of % - % of the pipe from the other end shall be sealed with a wooden plug， and the pipe shall be rotated every min. If degreasing is required for stainless steel elbow， degreasing solvent shall be appropriately added to make it fully soaked. After degreasing， pour out the solvent in the pipe， dry the pipe with exhaust fan， or dry it with natural air. Large diameter pipes can be manually scrubbed with cotton cloth dipped in solvent; The square tube can also be soaked in a long tank containing solvent for to minutes. The concentrated pipeline and equipment of the concentrated unit can be directly pumped and circulated with % concentrated for pickling after all installation. Pipes that cannot circulate or are not resistant to concentrated corrosion must be degreased separately.