Lessbridge159 galvanized square pipeWeak market

LessbridgeQ235 hot dip galvanized rectangular pipe,

After the sample is flattened to the specified flattening distance h, remove the load and remove the sample.

Yield point of square tube (& sigma; s): the stress of metal material with yield phenomenon when the sample can continue to elongate without increasing (maintaining constant) the force during the tensile process, which is called the yield point. If the stress decreases, the upper and lower yield points shall be distinguished. The unit of yield point is nmm2 (MPA).

Lessbridge.Cold rolled pipe, cold drawn pipe, hot rolled seamless pipe, etc. are produced on the automatic precision pipe rolling mill. The solid pipe blank is cut into the required length by removing surface defects, centered on the end face of the perforated end of the pipe blank, and then sent to the heating furnace for heating. It is perforated on the piercer. At the same time, it rotates and advances continuously under the action of roll and plug, A cavity is gradually formed inside the pipe blank, which is called the rough pipe, and then sent to the automatic pipe mill for continuous rolling. After the wall thickness is adjusted by the whole machine, and the diameter is determined by the sizing machine to meet the specification requirements. The continuous pipe mill is more advanced in producing hot-rolled seamless steel pipe. If you want to obtain seamless pipe with smaller size and better quality, Cold rolling and cold drawing must be adopted, or the combination of cold rolling and cold drawing is usually carried out on the roll mill. The seamless pipe is rolled in the annular pass composed of variable section circular hole groove and fixed conical plug. Cold drawing is usually carried out on the single chain or double chain cold drawing machine, that is, the heated pipe blank is placed in a closed cylinder, and the perforated rod and rod move, This method can produce steel pipe with small diameter. In the building materials industry, the development of various pipes is different. Because of their different characteristics there is a certain distance between pipes. Square pipe is one of many pipes in the building materials industry. It is formed after strip steel treatment. We need to understand the various characteristics of steel pipes. However, in the building materials industry, the development of various pipes is different. Because of their different characteristics, there is a certain distance between pipes. Square pipe is one of many pipes in the building materials industry. It is formed after strip steel treatment. The various characteristics of steel pipe need to be understood by everyone. However, due to the of steel pipe and other raw materials, qq355b square tube will have excellent rolling fatigue characteristics and corrosion resistance. Wear resistance, impact toughness and bending strength. Therefore, in the subsequent production and application, qq355b square tube will be used as the material of rolling mill flap ball screw. The qq355b square tube of case hardening steel also has the surface compressive stress characteristics obtained by heat treatment,LessbridgeQuotation for galvanized square pipe, and its application range is expected to be improved and expanded.

.Square pipes are mainly used in engineering buildings glass curtain walls, door and window decoration steel structures, guardrails, machinery, automobiles, household appliances, shipbuilding, containers, electric power, agricultural construction, bicycle frames, shelves, fitness equipment, leisure and tourism, steel furniture, various specifications of oil casing, oil pipes and pipeline pipes, water, gas, sewage, air Heating and other fluid transportation, fire fighting and support, construction and other fields.

Galvanized q355b square pipe for low pressure fluid transmission, Standard No.: gbt3092-2008. The representative materials are the same as above. It is mainly used to transport low-pressure fluids such as water, gas, air and oil and add water or steam. The surface of square pipe shall be hot galvanized or cold galvanized.

Great relationship. Large fillet radius, insufficient blank holder area, easy to produce unstable wrinkles; If the fillet is too small, the resistance of the material into the die will increase in the deformation process, and the material is not easy to move and transfer inward, thus increasing the large tensile stress in the force transfer area which may lead to tensile cracking.

The selected punch and die fillets are related to the magnitude and distribution of stress

In the square tube production process of welding before forming, the forming is mainly completed by the sizing frame. The sizing machine is generally a two high mill, including horizontal frame and vertical roll frame. At present, there are mainly two kinds of square pipe pass design: one is the horizontal frame is designed according to the box hole, the frame is an elliptical hole, and the other frames are approximately rectangular holes. The pass section is composed of circular arc. Professional projects include: square pipe, square pipe, seamless square pipe, galvanized square pipe, galvanized pipe and other related businesses. Please welcome merchants who want to have this business. And the arc radius increases frame by frame, The fillet radius of the joint between the side wall and the bottom of all pass patterns is equal to the fillet radius of the finished section. The total elongation coefficient of the square tube is about 05, which is mainly distributed on the flat roller. The deformation of the vertical roller is very small, and its function is to press down the short side of the square tube. With this design,LessbridgeDimensions of galvanized square pipe, the calculation is complex and the calculation value is not accurate enough. It is necessary to constantly correct the pass circumference.

Due to the interaction between chromium and carbon in martensitic chromium nickel square tube, stable R phase region and stable a + R phase region are formed at high temperature. The increase of carbon content can expand the R-phase region, but the dissolution limit of carbon decreases with the increase of chromium content. The addition of nickel to martensitic chromium nickel square tube solves the problem that the hardness of steel is sacrificed to improve the corrosion resistance of martensitic square tube. However, the nickel content is not easy to be too high, otherwise the square tube will become austenite square tube due to nickel expanding austenite phase zone and reducing MS temperature, so as to completely lose the quenching ability.

Supply chain quality management.The square tube is a low-alloy high-strength structural steel with carbon content of 0.1% - 0.25%, and the main alloy elements manganese, silicon, vanadium, niobium and titanium are added; Its total alloy content is 3%. According to the strength, it is divided into four levels: 300, 350, 400 and 450MPa.

The standard number of square pipes for transporting flammable and non flammable fluids is gbt97 1 (gbt97 - 199 represents steel for l245-l4 and other pipelines. It is mainly used for transporting flammable and non flammable fluids, low-pressure or high-pressure square pipes, with high requirements.

It is mainly caused by the fact that the square pipe body has no cover, the covering protection is not ideal, and there is no support, partly due to the excessive number of stacking layers, and most coastal areas belong to marine climate, with large annual rainfall, high air humidity, ponding in the square pipe and the square pipe. The protection shall be: if the bare pipe or pipe needs to be stored for a long time it shall be protected with an uncovered object from the beginning of storage to avoid rusting, layer aging, edge warping and other phenomena of the square pipe.

At the same time, the heating temperature and heating time will also have a great impact on the performance of square tube. The heating of square tube blank is the key process to ensure that the square tube blank has enough plasticity and complete the smooth perforation. If the heating temperature is too high or the heating time is too long, the billet of the square tube will be burned and decarburized, and even the chemical composition of the square tube will be unqualified (unqualified carbon content), mm2. Elongation after fracture (& sigma;) in the tensile test n (Newton) so -- original cross-sectional area of the sample, agricultural and chemical machinery, glass curtain walls, automobile chassis airports, boiler construction, highway railings, housing construction, pressure vessels, oil storage tanks, bridges, power station equipment, heavy transportation machinery and other welded structural parts with high load, etc. Process classification: according to the production process, square tubes are divided into hot-rolled seamless square tubes, cold drawn seamless square tubes, seamless square tubes and q355b square tubes.

Common specifications of square tube: ~ 5 18 & times; 18× 0.4～ 5 20× 20× 0.4～ 5 25× 25× 0.6～ 0 30× 30× 0.6～ 0 34× 34×0～ 0 35× 35×0～ 0 38× 38×0～ 0 40× 40×0～ 5 44× 44×0～ 5 45× 45×0～ 0 50× 50×0～ 0 60× 60×5～ 0 70× 70×0～ 0 75× 75×0～ 0 80× 80×0～ 0 85× 85×0～ 0 95× 95×0～ 0 100× 100×0～ 0 120× 120×0～ 0 150× 150×0～ 0 180× 180×0～

Lessbridge.It is learned from the authority that if there is dirt on the outer surface of the square pipe during degreasing, 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, the end of the pipe can be tightly blocked with a wooden plug or closed with other. The degreasing solvent with the volume of 15% - 20% of the pipe from the other end shall be sealed with a wooden plug, placed in a flat and clean place or on a workbench with sleepers for 60-80min and the pipe shall be rotated every 20min. 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 oil-free compressed air or nitrogen, 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 60 to 80 minutes. The concentrated pipeline and equipment of the concentrated unit can be directly pumped and circulated with 88% concentrated for pickling after all installation. Pipes that cannot circulate or are not resistant to concentrated corrosion must be degreased separately.

The first is the influence of external conditions. It mainly depends on the medium characteristics and temperature around the square pipe and whether the medium around the pipe is corrosive. Because the corrosivity of the medium is closely related to the microorganisms contained in the soil. And if it is a long-distance pipeline, the soil environmental properties are more complex. In addition, the temperature of the environment where the pipeline is located will also affect the corrosion of the square pipe. If the temperature is high, the corrosion speed will also be accelerated, while if the temperature is low, the corrosion speed will be slowed down.

With the progress of the times, square tubes are used in more and more fields, and their scope of use is obviously increasing, we need to store square tubes reasonably. Customers should also learn to arrange reasonably when storing square tubes. Let's understand how to store square tubes correctly.