In this period the technology of continuous rolling pipe was not mature.Impact toughness the load acting on the machine part at a great speed by QB is called impact load, and the ability of metal under impact load is called impact toughness.Sverengrad,Elongation after square tube breaking (& sigma;): in the tensile test, the percentage of the length increased by the gauge length of the sample after breaking and the length of the original gauge length is called elongation. In & sigma; Expressed in%.. fake and inferior square tubes are easy to fold. Folding is a variety of broken lines formed on the surface of square tubes, and this defect often runs through the longitudinal direction of the whole product. The reason for the folding is that the fake and shoddy manufacturers pursue the rate, the reduction is too large, resulting in ears, folding occurs during the next rolling, the folded products will crack after bending, and the strength of the square tube will be greatly reduced.Kayunga,Due to the increase of square tube production there are more and more fake and shoddy square tubes in the market. How to distinguish the fake and shoddy square tubes? Let me teach you some points to distinguish the fake and shoddy square tubes.The first is to remove the rust of the square tube. When removing the rust of the square tube, the steel wire brush is mainly used to polish its surface, which can effectively remove the loose or rusty rust on the surface of the square tube.Compared with other welding, square pipe welding has many advantages, mainly because of the exothermic reaction, the material only needs to be heated below the melting point

The general delivery length of qb square pipe is mm-mm, or in the form of interface tubeIn & sigma; Expressed in%. The calculation formula is: where: L -- gauge length after sample breaking, mm; L -- original gauge length of sample, mm. Reduction of area (& psi;) in the tensile test, the percentage between the large reduction of the cross-sectional area at the reduced diameter and the original cross-sectional area after the specimen is broken is called the reduction of area. In & psi; Expressed in%. The calculation formula is as follows: where: S -- original cross-sectional area of the sample, mm; S -- small cross-sectional area at the reduced diameter after sample breaking, mm.Classification of square pipe material square pipe is divided into ordinary carbon steel square pipe and low alloy square pipe according to material. Ordinary carbon steel is divided into Q Q q SS, # steel, # steel, etc; Low alloy steels are divided into q Mn, Q, St-, etc.market price,Solution treatment and nondestructive testing sand rolling treatment and sand blasting treatment many manufacturers in the market do not do solution treatment and % penetration nondestructive testing, and many of them use sand blasting instead of sand rolling. After these steps are omitted, the cost is greatly reduced.If there is only a single plane weld, the step-by-step back welding shall be adopted from the middle,Sverengrad25 price of galvanized square pipe, the arc of the section weld shall be terminated at the section arc.The disadvantage of empty bending is that during synchronous empty bending at the upper and side, due to the pressure generated by the upper roll and the lower roll at the same time, the forming force is easy to exceed the critical point. All kinds of square tubes,SverengradCold galvanized square pipe factory, square rectangular tubes, seamless square tubes, galvanized square tubes and galvanized tubes have formal qualifications. Welcome to telephone inquiry and sincerely invite cooperation! It will cause edge instability and concave, and will also affect the stable operation of the unit and forming quality. This is also the different characteristics of qb square tube and round tube empty bending.

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).middleman,Functional index analysis of qb square tube - commonly used are Brinell angle (HB), Rockwell angle (HRC) and Vickers angle (HV) of qb square tube. Angle is a gauge needle to weigh the soft and hard level of metal data. The angle method is rarely used to determine the internal angle in the current life. It uses the metal data surface tested under the fixed load of the indenter with a certain number and shape to determine its angle value according to the level of the object.At the same time, 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) which is easy to cause batch quality problems and seriously affect the product qualification rate.The first is to remove the rust of the square tube. When removing the rust of the square tube, the steel wire brush is mainly used to polish its surface, which can effectively remove the loose or rusty rust on the surface of the square tube.Sverengrad,SverengradHow much is galvanized steel square tube,After chemical pickling, the square tube can be well protected by electrolysis. These are simple ways to prolong the service life of the square tube, We only need to treat according to these, so that the square tube can bring us great help in the use process. The cold galvanized square tube is the principle of cold galvanizing on the square tube used to make the square tube have corrosion performance. Different from hot-dip galvanizing, cold galvanizing coating is mainly carried out according to the electrochemical principle. Therefore, it is necessary to ensure the sufficient of zinc powder and steel, resulting in electrode potential difference, so the steel surface treatment requirements are very high.Hundreds of degrees Celsius, which can save energy.Welding seamless welding seamless is to make welded elbows. After grinding and pickling, sand blasting, it can not be seen that they are welded elbows.