When the square tube is covered, the surface of the square tube shall be ventilated to avoid the collection of water vapor on the surface due to difficult volatilization.
The square tube adopts the electric contact pressure gauge to press down the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth transportation of the strip steel.
Colima.Generally, since the q355b square tube material is selected as the base metal, it generally has special purposes, so the welding materials will not be selected casually. It is better to use it according to the welding material manual. If the welding rod manual says that the base metal should be preheated, it should be preheated. Because the welding materials are not used according to the manufacturer's instructions, the weld performance will be greatly reduced.
The raw material for rolling square tube is round tube blank. For a long time, square tube, rectangular tube, seamless square tube galvanized square tube and galvanized tube have complete products, and the blank with a growth of about 1m shall be brought to the furnace for heating. The billet is sent to the furnace for heating at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene. The temperature in the furnace is the key problem. After the round tube billet is discharged from the furnace excellent quality and favorable price. The round tube embryo shall be cut and processed by cutting machine, it should be pierced through the pressure piercer. Generally, the more common piercer is the conical roll piercer. This piercer has high production efficiency, good product quality, large perforation expansion and can wear a variety of steel grades.
It is feasible to use the theory to calculate static structures, such as warehouses houses and bridges, but it is not suitable for moving components such as wheels. At this time people often use the plastic theory. The research of the plastic theory can be traced back to 1914. In 1975, the European Design Association formulated a plastic design code, which is mainly used for static load plane beams and frame structures subjected to bending stress The solution is as follows: for high-rise buildings, more detailed calculations are needed.
Empty bending is the bending moment formed in one direction between the outer roll and the outer wall of the tube blank to bend the strip. Empty bending will compress the bending line, the compression effect will lengthen the bending line longitudinally, and the metal at the bending will accumulate and thicken, which is the compression thickening effect of empty bending.
Reinforcing phases such as reinforcing particles, short fibers and whiskers can be added to the solder to form composites.
The great difference between the square pipe and the thin-walled steel pipe produced by the square pipe factory lies in the thickness of the steel pipe wall. Generally speaking, the thin-walled steel pipe is cold drawn technology, while the square pipe generally uses hot rolling technology. If it is distinguished by the unit of measurement, and the thin-walled steel pipe is that the wall thickness diameter is less than 0.02, Larger than is the square pipe. In terms of use, thin-walled steel pipes are mostly used in pipes. The square tube is mostly used in the blank of hollow parts. Used on pressure bearing and important pipelines.
How many?.Avoid contact with pollutants such as oil and copper when storing square tubes.
Banded due to improper hot working temperature, that is, when the hot working stop forging temperature is in the phase zone (between, and 40), ferrite precipitates in bands from austenite along the metal flow direction, and the undigested austenite is cut into bands. When it is cooled to a, the banded austenite is transformed into banded pearlite. This can be improved or eliminated by increasing the final rolling temperature, increasing the forging ratio, diffusion annealing and normalizing.
According to the welding specification, process test and process analysis, it is determined that the butt weld of Q345B square pipe adopts double-layer CO2 gas shielded welding. H08Mn2SiA, 2mm welding wire for welding material; The shielding gas is pure CO2 gas. The welding current of layer weld is 200 ~ 250A, and that of the second layer is 240 ~ 320A; The arc voltage is 24 ~ 26V. The process requirement is that the layer weld must be fully welded to ensure good back forming; The welding current, arc voltage, wire feeding speed and welding speed can be adjusted according to the equipment model.
In the process of processing, the processing temperature is the key. Professional square tube, square tube, seamless square tube, galvanized square tube and galvanized tube have advanced technology, strict detection, more affordable price and more preferential price. Consultation is welcome. It must be noted that the blank heating should be uniform. Perforation has a great impact on the quality. The perforation temperature of blank varies according to different materials, generally around 1200 ℃.
Test method.With the progress of the times, and their scope of use is obviously increasing, which makes us have many kinds of square tubes. At this time, 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.
According 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).
HDPE plastic square pipe made according to the properties of square pipe has the advantages of light texture, high strength, good resistance, easy laying, low water resistance, low cost and corrosion resistance. Its service performance and economic benefits far exceed reinforced concrete pipe and general specification iron pipe. It is an updated product of engineering pipe.
Colima.Brinell hardness, Rockwell hardness and Vickers hardness are commonly used.
Square tube flattening test is a kind of test to check the deformation performance of metal tubes (seamless square tubes and rectangular tubes) flattened to the specified size and show their defects. Relevant flattening tests shall be carried out in accordance with relevant provisions of test standards. Requirements for samples samples can be taken from metal pipes with qualified appearance. Generally, sawing is adopted. The inner and outer walls of the pipe shall retain the original surface without any processing. Sample length L & asymp; D (D is the outer diameter of the pipe). When the outer diameter is large, the length l shall not exceed 100mm. When the outer diameter is less than 20mm, l = 20mm. When cutting the sample, the surface of the sample shall not be damaged and the performance of the metal shall not be changed due to heating or cold processing. The edge of the section shall be flattened. The flattening test is a test to check the deformation performance of the metal pipe (seamless square pipe and rectangular pipe) flattened to the specified size and show its defects. Relevant flattening tests shall be carried out in accordance with relevant provisions of test standards.
The flattening speed of the sample can be 20 ~ 50mmin.