In this period, the technology of continuous rolling pipe was not mature.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.Brosad,When we understand the causes of defects in the drawing process of qb square tube, we should constantly improve the technology in the subsequent production process,If the test results of square tubes fail to meet the provisions of product standards, the unqualified ones shall be selected, and double the number of samples shall be taken from the same batch of square tubes for re inspection of unqualified items. If the re inspection results (including any index required by the test of the project) are unqualified, the batch of square tubes shall not be delivered. If the following inspection items fail to pass the preliminary inspection, re inspection is not allowed: A. There are white spots in the low magnification; b. Microscopic.The difference between hot-dip galvanized square pipe and cold-dip galvanized square pipe is mainly from the following aspects: the appearance of hot-dip galvanized square pipe is slightly rough compared with cold-dip galvanized square pipe; The appearance of cold galvanized square pipe is smooth and bright.Change to square pipe: generally, 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. Stage ( & mdash; )

Purpose of square tube the purpose of square tube includes construction, machinery, steel construction and other projects, shipbuilding, solar power generation support, steel structure engineering, electric products ( pieces)Square tubes are more and more widely used in practice. Different types of square tubes have different characteristics, so as to improve its work efficiency. Next let's introduce what should be paid attention to when heating the lower tube.Forging square tube: a kind of pressure processing in which the reciprocating impact force of the forging hammer or the pressure of the press changes the blank into the shape and size we need. It is generally divided into forging and die forging. It is often used to produce large-scale materials and materials with large square tube size.Economic management,BrosadGalvanized square pipe machine,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.During the pushing process of spot welding and repair welding elbows, there will be thinning,BrosadGalvanized round iron pipe, so manufacturers usually use thick spot pipes. If thin raw materials are used, the products produced must be unqualified. Generally, there are about wires thinned. If the technology is not good or the drawn pipe is used, the thickness is significantly lower than the standard.The reason why the surface of fake and shoddy materials is easy to crack is that its blank is adobe with many air holes. During the cooling process, the adobe has cracks due to the action of thermal stress and there are cracks after rolling.

The floating mandrel mill is in its heydayMarket trend,: 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.Classification of wall thickness square tubes are divided into super square tubes, square tubes and thin-walled square tubes according to wall thickness. Gbt-gbt-gbt-, JG -, ASTM A JIS gen or technical agreement.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, and on the basis of this square tube, 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,Brosad4 galvanized square pipe, but this kind of square pipe needs little equipment and capital, which is more suitable for the production of small galvanized square pipe manufacturers.Brosad,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, and on the basis of this square tube, 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 this kind of square pipe needs little equipment and capital, which is more suitable for the production of small galvanized square pipe manufacturers.. fake and inferior square tubes are easy to fold. Folding is a variety of broken lines formed on the surface of square tubes, 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.Square tube is made of different materials. It needs qualified inspection by relevant staff before leaving the factory. Square tube has a wide range of uses. Its main field is not only the construction industry, but also can be seen everywhere in our daily life. The service life of square tubes is mainly affected by surface treatment. I will explain the specific operations of surface treatment of square tubes.