Welding seamless welding seamless is to make welded elbows. After grinding and pickling, sand blasting, there is no sign of welding on the surface. Even using advanced flaw detection equipment, it can not be seen that they are welded elbows.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, compared with straight seam pipe of the same length, square rectangular tubes which will be oriented to the whole country for a long time Individuals and enterprises provide all kinds of square tubes, seamless square tubes, galvanized square tubes, galvanized tubes, on-site settlement, honest operation, local offices, long-term cooperation and low production speed. Therefore, most of the smaller square tubes adopt straight seam welding, and most of the large-diameter square tubes adopt spiral welding.Biaroza,However, and its external quality directly affects its applicationSquare tubes for petroleum cracking (gb-) are furnace tubes, heat exchangers and pipeline square tubes suitable for petroleum refineries.Minna,Section shape classification of large-diameter qb square tube square tube is classified according to section shape: simple section square tube & mdash& mdash; Square tube, rectangular tube and complex section square tube & mdash& mdash; Flower shaped square pipe, open square pipe, corrugated square pipe, special-shaped square pipe, large-diameter qb square pipe surface treatment classification square pipe is divided according to surface treatment: hot-dip galvanized square pipe, electro galvanized square pipe, oil coated square pipe, acid pickling square pipe, large-diameter qb square pipe purpose classification square pipe is classified according to purpose & mdash& mdash; Square tubes for decoration, machine tool equipment, machinery industry, chemical industry, steel structure, shipbuilding automobile, steel beam and column, special purpose, large-diameter qb square tube wall thickness classification, large-diameter qb square tube according to wall thickness Classification & mdash& mdash; Super large diameter qb square pipe, large diameter qb square pipe and thin-wall large diameter qb square pipe rectangular pipe are the names of square pipe and QB square pipe, that is, the strip steel is unpacked, leveled, crimped and welded to form a round pipe, then rolled into a square pipe from the round pipe, and then cut into the required length. Usually pieces per bag. Qb square pipe also known as square and rectangular cold-formed hollow section steel, is referred to as square pipe and rectangular pipe, code f and j respectively. The allowable deviation of wall thickness of qb square pipe shall not exceed plus or minus % of nominal wall thickness when the wall thickness is not greater than mm, plus or minus % of wall thickness when the wall thickness is greater than mm, except for the wall thickness of corner and welding joint area.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.At this time, if the welding wire of the same material is used for spot welding where the thickness is insufficient, it shall be welded to the fixed thickness,Biaroza5050 galvanized square pipe, ground and sandblasted, and repair welding shall be adopted where there are cracks, even if the steel pipe with another large opening can be made up at one time.

Steel for construction and engineering according to the classification of use without phase transformation or partial phase transformation of square tube: A. ordinary carbon structural steel; b. Low alloy structural steel; c. Steel reinforcement.When processing the square tube, such as arc, electric spark, flame, strong current, high-temperature furnace, electron beam, laser, high-temperature radiation, microwave, chemical furnace, etc.Safety and health,Steel for construction and engineering according to the classification of use without phase transformation or partial phase transformation of square tube: A. ordinary carbon structural steel; b. Low alloy structural steel; c. Steel reinforcement.The principle is similar to that of the plate rolling machine. The bending machine can determine a circle. Adjust the height to adjust the curvature.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, 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.

Mechanical engineering, power plants, 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 qb square tubes.Where to sell API,: 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, 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.When cutting, please fix it with square tubes such as vise, and then cut it after it is fixed.The second is the pickling of the square pipe. Both chemical and electrolytic methods are used when pickling the square pipe. These two methods can remove the oxide skin of the square pipe.Biaroza,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.Zinc layer thickness: there is a great difference between cold galvanized square pipe and hot galvanized square pipe in galvanizing process; Cold galvanized square pipes are prone to & ldquo; Electric burning & rdquo; The color of this part is gray and the zinc layer is thick. It is easy to form a current dead angle at the corner, resulting in an under current area. The zinc layer at this part is thin, and there is no zinc layer attached to the cold galvanized square pipe. The cold galvanized square pipe has no zinc lump and caking as a whole, but the overall zinc layer is thin, and the thickness of the outer wall zinc layer is μ m-μ m. The and outer walls of the hot-dip galvanized square tube are attached with zinc layer, and there will be water marks and a few zinc tumors, but the overall zinc layer is thick, and the thickness of the zinc layer on the inner and outer walls of the square tube is -mu; M above. The nature of QB square tube!Square tube nonferrous metals, also known as non-ferrous metals, refer to metals and alloys other than ferrous metals, such as copper, tin,BiarozaDN80 galvanized square pipe, lead, zinc, aluminum, bronze, aluminum alloy and bearing alloy. In addition, chromium,Biaroza40 thickness of galvanized square pipe, nickel, manganese, molybdenum, cobalt square tube, vanadium, tungsten, titanium, etc. are also used in industry. These metals are mainly used as alloy additives to improve the performance of metals. Tungsten, square tube titanium molybdenum, etc. are mostly used to produce cemented carbide for tools. The above non-ferrous metals are called industrial metals. In addition, there are precious metals: platinum, gold, silver and rare metals, including radioactive square tubes.