Cleaning solvent and emulsion can clean the surface of square tube to remove oil, grease, dust, 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.B. low alloy structural steel C. ordinary structural steel and high-quality steel for specific purposes (including high-quality steel)Lezhe , we should choose them according to their characteristics. We have different types of square tubes in different fields. What is the difference between the characteristics of square tubes and ordinary steel tubes? Let's introduce them today to let us have a deeper understanding of each other's tubes.Alloy steel: A. low alloy steel (total alloy element content & le; %); b. Medium alloy steel (total alloy element content > ~ %); c. High alloy steel (total alloy element content > %).Flong,Principle of cold drawing strengthening: the lattice defects of steel increase during plastic deformation, and the serious distortion of defect lattice will hinder the progress and slip of lattice, so the yield point of steel increases and the plasticity and toughness decrease. Due to the internal stress in plastic deformation, the modulus of steel decreases. The cold drawn reinforcement is stored at room temperature for ~ d or heated to ~ ℃ and maintained for a fixed time. This process is called aging treatment.Special performance steel: A. stainless and acid resistant steel; b. Heat resistant steel: including oxidation resistant steel, heat strength steel and air valve steel; c. Electric heating alloy steel; d. Wear resistant steel; e. Low temperature steel; f. Electrical steel.In this period, the technology of continuous rolling pipe was not mature.

Among them, qb square tube is divided into: (a) by process & mdash& mdash; Arc welded square pipe, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Straight seam welded square pipe, spiral weldingQb square tube is a kind of hollow square section steel square tube, also known as hollow cold-formed section steel. It is a section steel with square section shape and size made of hot-rolled or cold-rolled strip or coil plate after cold bending and high-frequency welding.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.where,Special performance steel: A. stainless and acid resistant steel; b. Heat resistant steel: including oxidation resistant steel, heat strength steel and air valve steel; c. Electric heating alloy steel; d. Wear resistant steel; e. Low temperature steel; f. Electrical steel.Hardness hardness is a pointer to measure the hardness and softness of metal materials. At present,Lezhe Galvanized spiral welded pipe manufacturer, 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.The general delivery length of qb square pipe is mm-mm, mostly mm and mm. Qb square tube is allowed to deliver short length and non fixed length products not less than mm, or in the form of interface tube

Comprehensive classification ordinary steel A. carbon structural steel: (a) Q (b) Q (b); (c) Q( C)； (d) Q( B)； (e) Q.Marketing Department,Lezhe Small galvanized square pipe,The other is designed with deformation angle, which can be regarded as DEG from round tube to square tube; To & deg; The bending deformation of angle, so the deformation angle & theta; It can accurately reflect the deformation degree of corners and edges. In the design process, considering the influence of dimensional accuracy and metal work hardening, the distribution of deformation angle is usually larger at the beginning and middle passes, and then gradually decreases. In the pass formed directly by arc intersection, the fillet part of the pipe blank cannot be filled with the pass, so the pass perimeter is different from that of the pipe blank. In order to ensure the dimensional accuracy, this method has higher design accuracy than other methods. However due to the large amount of iterative calculation, you can directly use the deformation angle & theta; Pass design.In the standard of qb square tube this method is more suitable for pass design by computer. If you use a frame that deforms both horizontally and vertically, most of them specify tensile test and hardness test at the same time. For those materials that are not convenient for hardness test, such as qb square tube, only tensile test is specified. In particular, the new portable surface Rockwell hardness tester and pipe Rockwell hardness tester can quickly and accurately test the hardness of stainless steel plate,Lezhe Galvanized square pipe direct selling, stainless steel strip and qb square tube as thin as .mm, which makes it easy to solve the problems that were difficult to solve in China in the past.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.Lezhe ,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.Functional index analysis of qb square tube - the load on the machine parts due to the great progress of strength is called the frontal collapse load. The power of destruction of qb square tube under the frontal collapse load is called the frontal collapse toughness.Square tubes for petroleum cracking (gb-) are furnace tubes