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,NewmarkHot dip galvanized rectangular pipe, seamless square tubes and qb square tubes.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,NewmarkHow much is 80 galvanized pipe, 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.Newmark,The purpose of heat is to prevent the generation of cold cracks. Cold crack is directly related to carbon equivalent. Therefore, it is necessary to distinguish the carbon equivalent of the qb square tube, and the carbon equivalent of the qb square tube is the same. If the carbon equivalent of Q is less than .%, it can be said that the weldability is OK. Generally speaking, the cold crack increases when the carbon equivalent is .%.Generally, sampling quantity, sampling position and test of square tube shall be in accordance with the provisions of corresponding product standards. With the consent of the demander, hot-rolled square tubes can be sampled in batches according to the rolled root array.If the re inspection results are unqualified (including the items whose preliminary inspection results are unqualified and re inspection is not allowed), the supplier can submit them for acceptance one by one; Or re conduct heat treatment (the number of RE heat treatment shall not exceed times), and propose acceptance with a new batch.The local heat release in the welding process of square tube can reduce the heat affected zone, avoid the micro of thermal sensitive materials, and maintain the properties of materials.

Ferroalloy is an alloy composed of iron and silicon, manganese, chromium, titanium and other elements. Ferroalloy is the raw material for steelmaking. It is used as deoxidizer and alloy element additive for steel in square tube steelmaking.Functional index analysis of square tube - commonly used are square tube Brinell angle (HB), Rockwell angle (hrahrbhrc) and Vickers angle (HV) Equal angle is a gauge needle to weigh the soft and hard level of metal data. In the current life, the angle method is rarely used to determine the angle. It uses the indenter with a certain number and shape to determine the angle value of the metal data surface being tested under a certain load according to the level.Square tubes for low and medium pressure boilers (gb-) are high-quality carbon structural steel hot-rolled and cold drawn (rolled) square tubes for superheated steam tubes, boiling water tubes for low and medium pressure boilers of various structures and superheated steam tubes, large smoke tubes,NewmarkCold rolled square tube, small smoke tubes and arch brick tubes for locomotive boilers. Square tubes for high-pressure boilers (gb- is a high-quality carbon steel, alloy steel and stainless heat-resistant steel square tube for the heating surface of water tube boilers with high pressure and above. High pressure square tube for chemical fertilizer equipment (GB - is a high-quality carbon structural steel and alloy steel square tube suitable for chemical equipment and pipelines with working temperature of - ~ ℃ and working pressure of ~ mA.install,Cold drawn or cold rolled precision square tube (gb-) is a cold drawn or cold rolled precision square tube with high dimensional accuracy and good surface finish for mechanical structure and hydraulic equipment. The selection of precision square mechanical structure or hydraulic equipment can greatly save machining hours improve material rate and improve product quality.Hundreds of degrees Celsius, which can save energy.Viewing color: the color of the cold galvanized square tube is yellowish green, cyan white or slightly colored at a fixed angle with the sun. The color of hot-dip galvanized square pipe is silver white at a fixed angle with the sun.

With the progress of the times and the development of science and technology, the application fields of square tubes are widely divided. The main fields are the construction industry. Affected by the environment and weather,For structure: as pile driving pipe and bridge; pipe for wharf, road and building structure marine pile driving pipe, etc.In order to ensure excellent coating quality, the coating is required to be firmly attached to the surface of the coated object. This depends on the quality of the coating itself; On the other hand, it depends on the quality of the coated surface treatment before construction. After various surface treatments, the coating quality and economic effect are very different.It should be noted that the position of the disc from the calibration line can be adjusted according to the reinforcement diameter, and R and R can be equal or different.Newmark, I'll lead you to learn its cold drawing principle.Derusting grade for the construction process of epoxy, ethylene, phenolic and other coatings commonly used for square pipes, the surface of square pipes is generally required to reach near white grade (SA). Practice has proved that almost all oxide scale, rust and other dirt can be removed by using this derusting grade, and the depth of anchor grain can reach ~ & mu; m, which fully meets the requirements of adhesion between layer and square pipe The shot derusting process can meet the technical conditions of near white level (SA) with low operation cost and stable and reliable quality.Plasticity QB square plasticity refers to the ability of metal materials to produce plastic deformation (deformation) without deformation under load.