The advantage of empty bending is that it can bend the side length when the real bending cannot be carried out, such as synchronous bending and finishing of the upper side and side of qb square tube. Empty bending can also bend the inner corner of r.t without breaking the tube wall.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 > %).Maypen, 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 .%.If there is only a single plane weld, the step-by-step back welding shall be adopted from the middle, that is, the arc of the section weld shall be terminated at the section arc.Viru,Ship carbon steel square pipe (gb-) is a carbon steel square pipe for ship class I pressure pipe system, boiler and superheater. It is a long-term business square pipe, square pipe, seamless square pipe, and the working temperature of alloy steel square pipe wall shall exceed ℃.The appearance of fake and inferior square tubes often has pitting. Pockmarked surface is an irregular uneven defect on the surface of square lead pipe due to serious wear of rolling groove. Due to the pursuit of profit by fake and shoddy square tube manufacturers, the rolling of rolling groove often exceeds 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 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 tubeThe square tube shall be painted correctly. Professional square tube, square rectangular tube, seamless square tube, galvanized square tube and galvanized square tube have stable, safe and reliable performance and can be maintenance free. The technical level has reached the domestic level and the advanced level of similar international products. Otherwise, the square tube will be corroded. The correct paint shall also be selected during painting, so as to ensure that the square tube can be used more firmly, So as to ensure that the square tube will be better and better in future use. The square tube is widely used in the soul. Each kind of square tube has different functions for the other tube. We choose the right way and different square tubes, which can increase the performance of the square tube and be applied to different fields. Let me briefly introduce the lower tube.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, 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.Executive standard,During the pushing process of spot welding and repair welding elbows there will be thinning, so manufacturers usually use thick spot pipes. If thin raw materials are used, the products produced must be unqualified. Generally, the thickness is significantly lower than the standard.Welding is a synthetic gradient material, which can be used as solder to weld special-shaped materials in order to overcome the mismatch of chemical, mechanical and physical properties between base metals.Welding seamless welding seamless is to make welded elbows. After grinding and pickling,Maypen80 galvanized rectangular pipe, 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.

Brinell hardness (HB),MaypenGalvanized seamless pipe, Rockwell hardness (HRC) and Vickers hardness (HV) are commonly used.total costSquare tubes are classified by forming: forged steel; Cast steel; Hot rolled steel; Cold drawn steel.Effective treatment of square tube coating & ldquo; Surface defense line & rdquo; Surface technology and measures square tube coating is used as the back course & ldquo; Surface defense line & rdquo; The surface treatment technologies and measures can be carried out on the basis of other surface treatment technologies or processes. Here's the & ldquo; Surface treatment before coating & rdquo; It refers to all treatment measures for preparation for coating or joint protection with coating. Therefore, the surface treatment before coating is also called coating surface pretreatment.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, the fillet part of the pass needs to be corrected and calculated. Therefore, this method has higher design accuracy than other methods. However, due to the large amount of iterative calculation, this method is more suitable for pass design by computer. If you use a frame that deforms both horizontally and vertically you can directly use the deformation angle & theta; Pass design.Maypen,The floating mandrel mill is in its heydaySquare pipe welding is suitable for surface treatment of materials. Square pipe welding can be used for ceramic ceramic, metal ceramic and metal metal welding.Carbon steel classified by chemical composition: square tube A. low carbon steel (C & le; .%); b. Medium carbon steel (C & le; . ~ .%); c. High carbon steel (C & le; .%).