steel tube

　　Production of cold drawing petroleum cracking tube can be cold-rolled, cold drawn, cold-drawn, cold-mix production. Using drawing process, a simple equipment, low investment, easy operation and maintenance and so on. But the drawback is the middle step of many, lumber rate. Using cold process equipment is more complex, and more investment, but can reduce the intermediate processes, improve the yield, high seamless steel product size, and surface accuracy, especially for high-precision seamless and extremely thin-walled seamless tube . 　　Due to limitations mill roll pass by the number and cost of finished product specifications can not be too much; cold-rolled and cold drawn joint production process to produce the finished product, with good quality steel processing cycle time is short, reduce intermediate degreasing, heat treatment, faint, Jiao straight processes, saving energy, reducing metal consumption, less raw material specifications and so on. Petroleum cracking tube can be c...

　　Hot-rolled seamless steel pipe from the tube to the product generally requires two heating, which perforated tube before and after heating and rolling blank pipe diameter at a given pre-heating; production of cold-rolled (pull) when the pipe requires the use of an intermediate annealing to eliminate the residual stress; steel for some special requirements, in order to improve the mechanical properties of steel pipe and improving organizational and process performance, but also its heat treatment. Common tube (pipe) heating tube defects uneven heating, oxidation, decarbonization, heating cracks, overheating, over-burning. 　　Heated front perforated tube, and its purpose is to improve the ductility; reduce deformation resistance steel; provide good microstructure is rolling. There annular furnace tube furnace, reheating furnace, inclined hearth furnaces and car bottom furnace. Given the shortage of pipe diameter before reheating, which aims to increase the temperature of the tube and ...

　　 Hot rolled seamless steel tube : hot rolling is related to the cold drawn, hot rolling is performed above the recrystallization temperature of the rolling. 　 　Hot-rolled seamless steel tube advantages: 　　Ingot casting can destroy tissue, grain refinement of steel and eliminate defects microstructure, so that the steel dense tissue mechanical properties are improved. This improvement is mainly reflected in the direction along the rolling direction to a certain extent, the steel is no longer isotropic; pouring formed bubbles, cracks and loose, can be welded at a high temperature and pressure. 　 　Hot-rolled seamless stee tube disadvantages: 　　1. After hot rolling, the steel inside the non-metallic inclusions (mainly sulphide and oxide, and silicates) is pressed into the sheet, delamination (interlayer) phenomenon. Layered in the thickness direction of the steel tension performance deteriorated significantly, and there may be an interlayer tear weld shrinkage. Weld local strain-...

　　In spiral welded pipe technology, forming angle is an important parameter, which refers to the angle (acute angle) helical axis of spiral welded steel production (tube) after welding and forming the center line between it and the strip (tube) width, coil diameter, stress and productivity have a certain relationship. 　　Relationship with the strip forming angle (tube) width and diameter spiral welded pipe 　　Under certain circumstances the width of the strip, forming angle changes directly affect changes in pipe diameter, while the diameter of the steel pipe of the same strip of different widths can be used, the use of different molding angle molding. From the production feasibility and economic considerations, strip width and pipe diameter ratio is a certain boundary and scope. From an economic consideration, forming angle smaller productivity is higher, if a 30 °angle than molding molding using 50 °angle to produce the same yield about a quarter the diameter of the pipe. From feas...

　　There are three main types of modern steel pipe production, namely welded pipes, seamless steel pipes and seamlessness pipes. 　　The welded pipe is formed by deforming the metal strip into a tubular shape and welding and forming at the welded joint. The welded pipe can be divided into furnace welding, high-frequency electric resistance welding, argon arc welding and ion welding according to the welding process; For straight seam welding and spiral welding. Common natural injuries in welded pipes include slag inclusions, cracks, pores, and virtual welds. 　　The seamless tube is processed into a capillary tube by a punching machine or an extruder, and then rolled and formed by a rolling mill. The small-diameter tube and the thin-walled tube are subjected to repeated cold rolling-annealing process. Common natural injuries to the seam tube include longitudinal cracking, transverse cracking, folding of the inner and outer walls, and warping, pitting, pitting, and delamination. 　　The s...

　　Nowadays, with quick construction of society and rapid development of technology, more and more different kinds of steel pipes are created, such as welded steel pipe, seamless steel pipe, ERW steel pipe and so on, and more and more steel pipes are needed. In the competitive market of steel pipe, ERW steel pipe, seamless pipe and welded steel pipe are well sold thanks to their specific characteristics. 　　There are a few aspects of differences between ERW steel pipe and seamless steelpipe. ERW pipe, which is short for electric resistance welding, is used in delivery of liquid, such as fuel, gas and so on, regardless the requirement of pressure, which plays an important role in the conveying tube all over the world, while seamless pipe is a kind of steel pipe shaping square and rectangle and having no seam around with hollow cross-sections, which is used in conveying liquid but also making structural members and machine parts, due to its surprisingly high anti-bending and anti-torque...

　　This new manufacture technique of a kind of API steel pipe which belongs to straight seam welded steel pipe is being widely accepted around the world. As a matter of fact, the API steel pipe is a kind of welded steel pipe that has no seams. Although the API steel pipe has not many applications like the welded steel pipe, the API steel pipe is mainly used for industry that links to the oil. And its application is increasing because of the increasing of the oil demand. 　　This kind of manufacture technique controls reasonably the sulfur content of carbon, phosphor as well as the sulfur and adds to a trace of alloying elements at the same time. The manufacture method of this straight seam welded steel pipe( API steel pipe) is that first, carry out pretreatment to the molten iron, and then proceed with smelt, refine, sheet stamping, hot rolling, laminar flow cooling, plate rolling, seam welding as well as test. And in the middle of welding technique, it is better to control the paramet...