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.The characteristics of square pipe are as follows: the production process of square pipe is simple, the production efficiency is high, the cost is low and the development is fast. The strength of spiral square pipe is generally higher than that of straight seam square pipe. It can produce square pipe with larger pipe diameter with narrow blank, and square pipe with different pipe diameter with blank of the same width. However, compared with straight seam pipe of the same length, the weld length is increased by ~ which will be oriented to the whole country for a long time Individuals and enterprises provide all kinds of square tubes, square rectangular tubes, seamless square tubes, galvanized square tubes, galvanized tubes, on-site settlement, honest operation, local offices, and low production speed. Therefore, most of the smaller square tubes adopt straight seam welding,san diego 90 galvanized square pipe, and most of the large-diameter square tubes adopt spiral welding.san diego ,The general delivery length of square pipe is mm-mm mostly mm and mm. The 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 allowable deviation of the wall thickness of square pipe shall not exceed plus or minus % of the nominal wall thickness when the wall thickness is not greater than mm, plus or minus % of the wall thickness when the wall thickness is greater than mm, except for the wall thickness of corners and weld areas. The weight of short gauge and non fixed gauge products shall not exceed % of the total delivery. For square tubes with a theoretical weight greater than kgm, In this way, the use efficiency of square tube can be improved. Next, we will mainly explain the characteristics of pipe cooling technology below. What are the main characteristics of square tubes? Square tube parts have accurate dimensions and smooth surfaces: the dimensional accuracy of cold parts developed at present can reach grade ~ . If ideal ones are adopted, their accuracy is second only to that of fine polished surfaces. Therefore, cold parts generally do not need to be reprocessed, and a small amount only need finishing (grinding).Brinell hardness (HB), Rockwell hardness (HRC) and Vickers hardness (HV) are commonly used.Hung Yen,The strength, plasticity and angle discussed later are the machine function indicators of metal under static load. In practice, many mechanical machines are under repeated load, and the whole opportunity is tired in this environment.. 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.Hot dip galvanized square tube is a kind of square tube which is welded after using steel plate or steel strip to curl and form, the square tube is placed in the hot dip galvanized pool and formed through a series of chemical reactions; The production process of hot-dip galvanized square pipe is relatively simple, but the production efficiency is very high and there are many specifications and varieties, but this kind of square pipe needs little equipment and capital, which is more suitable for the production of small galvanized square pipe manufacturers.

The surface of fake and inferior square tubes is easy to produce scabs. There are two reasons: the material of fake and inferior square tubes is uneven and there are many impurities. The guide equipment of fake and shoddy material manufacturers is simple and easy to stick to steel. These impurities are easy to scar after biting the roll.During the storage of square tubes, pay attention to the stacking layers of square tubes to avoid local stress at the tube end caused by too many layers, resulting in radial plastic deformation and layer damage of square tubes. It is recommended that the stacking layers of smooth pipes refer to apirp l- Recommended Practice for railway transportation of square pipes for pipelines or apirp lw- Recommended Practice for ship and sea vessel transportation of square pipes for pipelines. It can also be determined by test or implemented according to the safe stacking height of square pipes. The stacking layers of pipes shall be implemented according to GBT - polyethylene layer of buried steel pipelines.Cleaning solvent and emulsion can clean the surface of square tube to remove oil, grease, agent and similar organic matter, but it can not remove rust, scale, welding, etc. on the surface of square tube, so it is only used as an auxiliary means in production.Where is good,: it refers to the processing of square tube, which places metal in a closed Jane and applies pressure at the end to extrude the metal from the specified die hole to obtain finished products with the same shape and size. It is mostly used to produce non-ferrous metal materials. Square tube ferrous metal,san diego Specification table of 4-point galvanized pipe, steel and non-ferrous metal. Before introducing the classification of steel, briefly introduce the basic concepts of ferrous metal, square tube steel and non-ferrous metal.The strength, plasticity and hardness discussed above in fatigue QB are the indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.For oil, the oil brush work shall be carried out in accordance with the requirements of the rule system, so as to ensure the oil brush and the oil in the correct position of the brush and avoid wrinkles.

The disadvantage of empty bending is that when the upper side and side are synchronously empty bending, the forming force is easy to exceed the critical point due to the pressure generated by the upper roll and the lower roll at the same time, resulting in edge instability and concave, and will also affect the stable operation and forming quality of the unit. This is also the different characteristics of qb square tube and round tube empty bending. The concept of square tube: square tube is the pressure processing of ingot,san diego DN32 galvanized pipe outer diameter, billet or square tube Make materials of all shapes, sizes and properties we need.Quality inspection report,Fake and shoddy square tubes are easy to scratch, because the equipment of fake and shoddy material manufacturers is simple and easy to produce burrs and scratch the surface of square tubes. Deep scratches reduce the strength of square tubes.After the square pipes are stacked and stored, the pipe end protector shall be removed to avoid moisture gathering on the surface of the pipe end protector and the square pipe, which is difficult to volatilize.Precision inner diameter square tubes for hydraulic and pneumatic cylinders (gb-) are cold drawn or cold-rolled precision square tubes with precision inner diameter for hydraulic and pneumatic cylinders.san diego ,Hardness QB square hardness is a pointer to measure the hardness and softness of metal materials. At present, the hardness method is commonly used to measure the hardness in production. It uses the indenter with fixed geometry to measure the hardness value of the metal material surface tested under fixed load according to the degree of hardness.Spraying (throwing) derusting spraying (throwing) derusting is that the high-power motor drives the spraying (throwing) blade to rotate at high speed, so that the steel sand, steel shot iron wire section, which can not only completely remove rust minerals and other abrasives can be sprayed (thrown) on the surface of the square tube under the action of centrifugal force, oxides and dirt, but also the square tube under the violent impact and force of abrasives, It can also achieve the required uniform roughness.Ship carbon steel square pipe (gb-) is a carbon steel square pipe for ship class I pressure pipe system, class II pressure pipe system, boiler and superheater. It is a long-term business square pipe, square pipe, seamless square pipe, galvanized square pipe and galvanized pipe. Welcome to consult. The working temperature of carbon steel square pipe wall shall not exceed ℃, and the working temperature of alloy steel square pipe wall shall exceed ℃.