steel tube

　　Wrong Side of High Frequency Straight Seam Welded Pipe : 　　Wrong side of high frequency straight seam welded pipe is the most common pre-welding problems, ultra-poor of the wrong side will directly lead to the degradation of steel or scrap. Therefore, pre-welding requires strict control of the amount of wrong side. When the whole root or half of the steel pipe billet error occurs when the general is due to: 　　1, Open seam adjustment is not in place (seam side); 　　2, The joint pressure roller adjustment is not in place (pressure roller circumferential angle is not right, or to the tube centerline as the axis, the left and right pressure roller asymmetry, or the relative pressure roller radial extension is inconsistent), no pressure round; 　　3, The pre-bend is not pre-bending in place, there is a straight edge edge of the phenomenon. 　　When the head or tail of the tube is wrong, it is generally due to: 　　1, The import and export roller position is not right; 　　2, Ring fra...

　　Pre-welding quality of straight seam steel pipe includes seam quality and weld quality. 　　(1) Joint (that is, forming seam) no wrong side or wrong side is less than the specified value, the general provisions of the wrong amount ≤ 8% thickness, the maximum does not exceed 1.5mm. 　　(2) To ensure that the weld has a suitable penetration depth and welding volume, it is necessary to ensure that after welding does not crack, does not produce burning phenomenon, but also to control the weld height, the weld weld height does not have an impact. 　　(3) The weld is continuous, good shape, in order to help ensure the final external welding quality. 　　(4) Weld does not exist welding bias, pores, cracks, slag, burning and back welding and other defects, requiring weld center deviation ≤ 1 mm. 　　(5) No arc burns, splash small, does not affect the tube end groove and surface quality. 　　(6) Weld and base metal match, weld metal physical and chemical properties to meet the quality requir...

　　 Straight seam steel pipe fracture, hydraulic (pneumatic) parts in the design of the use of mechanical properties, brittle fracture is also related to the use of components temperature. 　　It has been found that when the temperature is below a certain temperature, it is found that the information will be transformed into a brittle state, and its impact absorption is significantly reduced. This phenomenon is called low stress brittle fracture in cold brittle and high strength metallic materials. In the process, the data organization is far from uniform, isotropic, there will be cracks, there will be inclusions, pores and other defects, these defects can be seen as micro-cracks in the material. Therefore, the design should also be based on the work of the component temperature to select the appropriate cold brittle transition temperature of the information. 　　In general, it is assumed that the information is uniform and continuous isotropic, according to this method analysis is con...

　　Effects of Deoxidizer on High Frequency Straight Seam Welded Pipe : 　　1.For the ω (Als ≤ 0.01% straight seam welded pipe, the use of two deoxidizer on the VD treatment of steel in the total oxygen impact is small, can be ω (T.O control in the 20 × 10-6 below; Si-Al-Ba deoxidation After the process can be a lower total oxygen content, the process of deoxidation effect is stronger than Si-Ca deoxidation effect. 　　2.When the Si-Ca and Si-Al-Ba two kinds of deoxidizer are used in the high-frequency straight seam welded pipe, the number and size of the inclusions in the smelting process are quite different. The number of inclusions in Si-Al-Ba Less than Si-Ca after deoxidation, and smaller size. 　　3.The inclusions in the forging material differ greatly from those in the aluminum inclusions. When the Si-Al-Ba deoxidation is used, the inclusions in the forging material are dominated by massive and chain alumina, and the high-frequency straight seam welded pipe uses Si-Ca deoxidation T...

　　The seamless steel pipe for fluid transportation is a general seamless steel pipe for conveying fluids such as water, oil, gas, etc., and a steel pipe having a hollow section and having no weld seam from beginning to end. The use of steel pipes to manufacture ring-shaped parts can improve the material utilization rate, simplify the manufacturing process, save materials and processing man-hours, such as rolling bearing rings, jack sleeves, etc., and have been widely used in steel pipes. Steel pipes are also indispensable materials for various conventional weapons, and barrels, barrels, etc. are all made of steel pipes. Steel pipes can be divided into round pipes and shaped pipes according to the shape of the cross-sectional area. Since the area of the circle is the largest under the condition of equal circumference, more fluid can be transported by the circular tube. In addition, when the circular section is subjected to internal or external radial pressure, the force is relatively un...

　　Several days ago, we introduced the types of tube that used in oil pipeline , today, we will share the connection modes of oil pipelines for people those interested in this aspect. 　　Oil pipeline must use a certain connection to form a complete system. Connection methods of pipeline are mainly three categories, including screw thread, welding and flange connection. 　　When the pressure is not high, the pipe with small diameter can be connected by using screw thread this method. This connection method is very convenient, but most of the diameter of oil pipelines are generally larger, so other two connection methods are used commonly. 　　The pipeline that DN≥50 basically uses welding method to connect. Welding has many advantages, such as convenient construction, strong, tight and saving steels. The general straight pipe or bends those parts do not need to tear down can use this method. 　　The connection of pipes and valves or other equipment (such as: pump) and the parts those ne...

　　Welded carbon steel pipe includes LSAW (longitudinal submerged arc welded) steel pipe and spiral welded pipe . Some people those do not very understand this industry may not know differences between the former and the latter very clearly. Don’t worry, today we will talk about this topic. 　　Spiral welded pipe is made by using low carbon construction steel strip or low alloy structural steel strip to roll into a tube according to a certain helix angle (called the forming angle), and then welding the seam together. It can use the narrow band steel to produce steel pipe with large diameter. Spiral welded pipe is mainly used for oil and natural gas pipeline, its specifications are expressed by outer diameter * wall thickness. Spiral welded pipe with also includes single-sided welding and double-sided welding. 　　LSAW steel pipe is made by using strip steel as raw materials and doing longitudinal welded in the high-frequency welding equipment(hence the name due to the weld forms a strai...

　　The biggest difference between water gas pipeline and galvanized steel pipe is that the former is seamed steel pipe and its pressure bearing capacity is low, the later is seamless steel pipe and its pressure bearing capacity is high. 　　Water gas pipes are constituted by welded steel pipes with thick wall, its materials are different from galvanized steel pipes. Water gas pipe is made of low-carbon steel welded pipe. those Galvanized are called galvanized iron tubes. Those non-galvanized are called black pipes. 　　Galvanized steel pipe is divided into cold galvanized steel pipe and hot galvanized steel pipe. The electroplating of hot galvanized steel pipe is relatively strong, its zinc layer is thick, and there is a blue ring logo on the head of galvanized pipe. Cold galvanized steel pipe is also made by electroplating, but it is made with less technology, and its performance is far worse, no blue logo. Cold galvanized steel pipe has been banned, hot galvanized steel pipe is promo...

　　The finished seamless steel pipe is sent to the inspection department for product quality inspection, which is an important measure to ensure the quality of the seamless steel pipe. Inspection standards and content are defined by national standards and some standards or technical conditions. 　　The inspection of the finished seamless steel pipe can be spot-checked and all. The spot check is generally to determine the mechanical properties, internal organization and chemical composition of the seamless steel pipe. In addition to sampling in a batch of seamless steel tubes, some seamless steel tubes for important purposes are sometimes inspected. In addition, hot-rolled seamless steel tubes are subjected to process tests such as flattening, bending, crimping and flaring, and hydrostatic tests according to standard requirements. 　　The inner and outer surface quality of the seamless steel pipe should be inspected with the naked eye or special equipment. Of course, the simplest inspec...

　　In general, seamless steel pipe uses Brinell, Rockwell, Vickers three hardness indicators to measure the hardness. 　　1. Brinell hardness test 　　In the standard of seamless steel pipe, Brinell hardness is used most, it often use indentation diameter to represent the hardness of the material, which is both intuitive and convenient. But it is not suitable for harder or thinner steel pipes. 　　2. Rockwell hardness test 　　The Rockwell hardness test of seamless steel tubes is the same as the Brinell hardness test, they are both indentation test method. The difference is that Rockwell hardness measures the depth of indentation. Rockwell hardness test is a widely-used method currently, HRC is next only to after Brinell hardness HB in the steel pipe standard. Rockwell hardness can be applied to measure metal material from very soft to very hard, which makes up for the weakness of Brinell method. And it is simpler than the Brinell method, it can read out the hardness value directly fro...

　　Structural welded steel pipe is used in steel structure, bridge support, building structural pipe, pile foundation tube, etc.. As the structural tube needs great egret capacity to pressure-bearing and withstand voltage, generally, we use the pipe that the wall thickness is greater than 8mm. The main material of the structural welded steel pipe is carbon steel, and mainly includes LSAW steel pipe, ERW steel pipe , and spiral welded pipe. The main parameters of the structural welded steel pipe include diameter, wall thickness, length, welding technology, whether the need for surface corrosion insulation treatment. The welded steel pipe for exporting needs to be grooved, painted, added the cap. Structural welded steel pipe is made with double-sided submerged arc welding or high-frequency welding. 　　Structural welded steel pipe is manufactured by continuous on-line production, the thicker the wall thickness is, the greater the unit and welding equipment investment is, the structural we...

　　In 1940 the United States first use UOE method to produce large diameter LSAW steel pipe . In the early 1950s, the United States built a LIOE pipe workshop with a diameter of 607 to 915 mm. 1955 ~ 1967 years of Europe, the United States, Japan UOE welded pipe construction workshop, the diameter of its pipe range of 406 ~ 1067mm, the maximum length of steel pipe is 12m. From 1967 to 1976, the maximum diameter of welded steel pipe was 1626mm, the pipe wall thickness was 40mm, the length of pipe was 18m, and continuous pre-welding and automatic nondestructive testing and automatic control were used in Germany and Japan. 　　Design scale and product program UOE pipe workshop design scale is generally 40 to 110 million t/a, the main varieties of high-quality carbon steel pipe, steel pipe yield strength of 750MPa, product specifications for the diameter of 406 ~ 1626mm, wall thickness 6. 4 ~ 40mm, length up to 18m. 　　Process UOE pipe material for the thick and thick steel plate, planing ...

　　In the production process of longitudinal submerged arc welded pipe ( LSAW steel pipe ), pipe manufacturers usually use laser weld seam tracking system. So what role does it play on LSAW steel pipe’s production process? Prime Steel Pipe will introduce it below: 　　 1.Improved the weld quality of LSAW steel pipe: 　　The main quality benefits of using the laser weld tracking system are: the system can always ensure that the weld is formed in the correct position, which greatly improves the quality of the welding. For example, Prime Steel Pipe’s system can better control the penetration of the roots than manual or mechanical tracking, as well as the penetration between the inner and outer joints. 　　 2.Progressive productivity: 　　The use of laser weld tracking system can significantly improve productivity. In the manipulator or operator-operated pipe press, the system is very easy to set up, the operator no need to worry about the location of the torch, can engage in other work. In...

　　We have mention the definition of hot rolling seamless steel pipe previously, today, Prime Steel Pipe will continue to talk about the advantages and disadvantages of hot rolling seamless steel tube with all of you. 　　Advantages of hot rolling seamless steel pipe 　　Can damage the ingot casting organization, refine the grain of steel, and eliminate the defects of microstructure, so that the steel structure is dense, mechanical properties improved. This improvement is mainly reflected in the rolling direction, so that the steel to a certain extent is no longer an isotropic body; pouring the formation of bubbles, cracks and loose, but also in the high temperature and pressure under the welding. 　　Disadvantages of hot rolling seamless steel pipe 　　1. After hot rolling, non-metallic inclusions (mainly sulfides and oxides, as well as silicates) inside the steel are pressed into flakes and delamination (interlayer). Stratification makes the performance of the steel in the thickness ...

　　Stainless steel hardness testing should take stainless steel seamless pipe’s mechanical properties into account, which relates to the stainless steel as raw material for deformation, stamping, cutting and other processing performance and quality. Therefore, all the seamless steel pipe need to be carried out mechanical performance testing. Mechanical performance testing methods are mainly divided into two categories, one is the tensile test, one is the hardness test. 　　The tensile test is to make the seamless steel pipe into a sample, pull the specimen to the fracture on the tensile tester, and then measure one or several mechanical properties, usually only to determine the tensile strength, yield strength, elongation at break and rate of reduction in area. Tensile test is the most basic mechanical properties of metal materials test methods, almost all of the metal material, as long as the mechanical properties are required, are provided for the tensile test. Especially those which...