During the pushing process of spot welding and repair welding elbows, there will be thinning, the products produced must be unqualified. Generally,Pidras nigrasGalvanized square pipe machinery, 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.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 > %).Pidras nigras,Hot rolled qb square tube continuous casting slab or blooming slab is used as raw material, heated by stepping heating furnace and descaled by high-pressure water into roughing mill. Roughing material enters finishing mill after head cutting, tail cutting and then computer rolling. After final rolling, it is rolled into straight hair coil through laminar cooling and coiler. The head and tail of straight hair curl are often tongue shaped and fish tail shaped, with poor accuracy of thickness and width, and there are often defects such as wave shape, hem,Steel used & mdash& mdash; Such as bridge steel, ship steel, boiler steel, pressure vessel steel, agricultural machinery steel, etc.Superior square tubular steel (both P and s ≤ .%)It is good to purchase Baosteel's materials for cold drawing of square tubes, and the density of steel is relatively good. After cold drawing and heating, it is convenient to line up. The steel is cold drawn at room temperature to produce plastic deformation, so as to improve the yield strength. This process is called cold drawing strengthening. Square tube is generally used for product parts with high requirements. It has good willfulness and strength. The surface is better after cold drawing. Cold drawing principle.

The strength plasticity and hardness discussed above in fatigue QB are the indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.There are several kinds of color qb square tubes: high temperature oxidation method, chemical oxidation method, electrochemical oxidation method, ion implantation method and gas phase cracking method.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.Promotion,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.The principle of straightening machine is that a disc is divided into two sides to clamp round steel straight lines. Professional square tube, seamless square tube, galvanized square tube, galvanized tube, high price service, on-site settlement,Pidras nigrasHot dip galvanized rectangular pipe, honest operation! The edge is one with radius r, and the other outer edge must be two equal diameters with radius R. The diameter of the reinforcement to be straightened is D, and the center distance between them is adjusted to R + R + D.Square tubes for petroleum cracking (gb-) are furnace tubes, heat exchangers and pipeline square tubes suitable for petroleum refineries.

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.Work courses,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.Process flow of square tube drawing: because the size of the die hole of the square tube drawing is smaller than the outer diameter of the tube in front of the drawing, in order to make the front end of the square tube pass through the die hole smoothly, so that the clamp jaw of the drawing trolley can the head of the square tube, it is necessary to sharpen the head of the square tube before drawing. Therefore, the end of the square tube with a fixed length should be heated in the slit heating furnace, It is generally ~ mm, and the heating temperature is between ~ ℃ according to different wall thickness. Then use ~ kg air hammer to sharpen and grind the head of the square pipe. Generally, the square pipe with diameter less than mm can be sharpened by rotary forging hammer or roll forging machine.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.Pidras nigras,When storing QB square pipe,Pidras nigras4 galvanized square pipe, such as the corrosivity of steel pipe, etc. Therefore, the place must be clean, dry and ventilated, where harmful gases appear, QB square pipe can not appear weeds and other sundries should be removed in time, and the outer surface of steel should be kept clean. If there are acid, alkali, salt, etc. in the warehouse, it is easy to react with the steel pipe and corrode the steel pipe, so try to cut it and don't let it. In addition if we can think about those higher metal products, we can put them into the warehouse for very good retention. According to geographical conditions, there is a sealed warehouse but the ventilation setting is excellent. The difference between QB square tube and seamless steel tube QB square tube is a kind of high-precision steel tube material after cold drawing or hot rolling treatment. QB square tube is mainly used to produce products of pneumatic or hydraulic components, such as air cylinder or oil cylinder, which can be seamless pipe or welded pipe, because there is no oxide layer on the inner and outer walls of QB square tube, no deformation under high pressure, high precision, high finish, cold bending, flaring and flattening without cracks. The chemical composition of QB square tube includes carbon silicon Si, manganese Mn, sulfur s, phosphorus P and chromium CR.Improve the positioning and pre bending steps, if necessary, to ensure that the web hunting problem does not occur when pressing parts. Change the shape of the surface pressure of the material to ensure the quality of the parts and avoid the non movement of the surface shape of the roll gap, resulting in uneven walking feeding.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.