steel tube

　　The seamless pipe line is mainly used for pumping high pressure oil and gas near the wellhead. As the corrosion problem of hydrogen sulfide is becoming more and more serious, the development of anti-sulfur seamless pipeline tube is urgent, and the anti-sulfur performance is the key. Discusses the influence of hydrogen induced crack (HIC) resistance of medium and material factors, Cu, Ni join can improve the performance of seamless line pipe material HTC reduce the S content in the steel, by spraying calcium silicon powder also can reduce the sensitivity of hydrogen bubble. 　　With the development of oil and gas exploration, the problem of hydrogen sulphide corrosion is very acute because of the increasing amount of oil and gas Wells in the complex and sulfur environment. In recent years, there has been an increase in demand for the seamless pipe line. The seamless pipeline pipe is mainly used for pumping high pressure oil and gas near the wellhead, and it is made by seamless tube p...

　　A tube is a closed shape used to perform some structural function. The shape can be round, square, rectangular or whatever can be designed and manufactured for a particular application. Round tubes differ from pipes in the way they are dimensioned. A 1 1/2-inch round tube has a 1 1/2-inch outside diameter. A 1 1/2-inch round pipe has a 1 1/2-inch inside diameter. The reason being that the outside of tubes is important for structures, however the inside of pipes is used for fluid flow. 　　 Welded Steel Tube 　　Welded steel tubing is made from either hot-rolled or cold-rolled steel that is provided to the tubing manufacturer in coils. The coil may be processed to remove scale, improve finish, amend heat treatment or in other ways to achieve the specified end product. The coil is then run through grooved rollers until the shape has been formed and the free edges are correctly spaced for welding. 　　The edges of the tube are butt welded together, generally with electrical resistance w...

　　A tube is a closed shape used to perform some structural function. The shape can be round, square, rectangular or whatever can be designed and manufactured for a particular application. Round tubes differ from pipes in the way they are dimensioned. A 1 1/2-inch round tube has a 1 1/2-inch outside diameter. A 1 1/2-inch round pipe has a 1 1/2-inch inside diameter. The reason being that the outside of tubes is important for structures, however the inside of pipes is used for fluid flow. 　 　 Seamless Steel Tube 　　The manufacture of seamless steel tube typically begins in an electric arc furnace. The steel is then cast as an ingot or continuously cast as a bloom. The bloom is then rolled into a billet. The solid billet becomes a tube by being drawn over a piercing tool by two external rollers set at an angle to each other that move the billet. At this point a “rough” tube has been formed. 　　The rough tube is put through an elongator, in which three rollers and an internal mandrel s...

　　Electric Resistance Welding (ERW) pipe is manufactured by rolling metal and then welding it longitudinally across its length. Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length. 　　In Seamless pipe, there are no welding or joints and is manufactured from solid round billets. The seamless pipe is finished to dimensional and wall thickness specifications in sizes from 1/8 inch to 26 inch OD. Applicable in for High-pressure applications such as Hydrocarbon Industries & Refineries, Oil & Gas Exploration & Drilling, Oil & Gas Transportation and Air and Hydraulic cylinders, Bearings, Boilers, Automobiles 　　etc. 　　ERW (Electric Resistance Welded) pipes are welded longitudinally, manufactured from Strip / Coil and can be manufactured upto 24” OD. ERW pipe cold formed from a ribbon of steel pulled th...

　　To identify that a pipe supplied is seamless or ERW , Simply read the stencil on the side of the pipe 　　If it is ASTM A53, Type S means seamless. 　　Type F is furnace but welded, 　　Type E is Electrical resist welded. 　　Thats how. It is the easiest way to identify wether pipe is seamless or ERW. 　　In short, Seamless is marketed on an outdated myth that it does not have flaws but that welded has an inherent flaw throughout the length of each tube, as stated above. Intuitively this concept is easily accepted by purchasers and designers with limited experience with the various products. Each product form and manufacturing method has its own inherent problems and potential defects.

　　Low carbon steel pipe has a large aging tendency, which means low carbon steel pipe has both quenching aging tendency and deformation aging tendencies. When the steel from the rapid cooling of high temperature, ferrite scraping carbon, nitrogen supersaturation, the formation of iron carbon nitrogen started slowly at room temperature. Which leads to the increase of strength and hardness, and the decrease of plasticity and toughness. This penomenon known as quenching aging. Low carbon steel pipe will produce aging even if not quenched and air cooled. 　　 Carbon steel pipe and nitrogen atoms interact with dislocations, and carbon and nitrogen atoms gather around the dislocation lines. This combination of carbon and nitrogen atoms and dislocation lines is called the Koch's air mass. It will increase the strength and hardness of steel and plasticity and toughness reduced, a phenomenon known as deformation aging. 　　Compared with quenching, deformation of low carbon steel pipe has a...

　　Under cold conditions a low-carbon steel welding, the cooling rate of the welded joint, which has made cracking tendency to increase, especially in the first weld Heavy structures susceptible to cracking, it is necessary to take the following process steps: 　　1) Do not possible under conditions of low temperature bending, correction and assembly weldments. 　　2) Preheat, 16Mn seamless steel pipe welding process strictly maintained interlayer temperature should not fall below the preheating temperature. 　　3) Hydrogen or ultra-low hydrogen welding. 　　4) The whole seam continuous welding should be completed to avoid interruption. 　　5) When positioning welding to increase the welding current, welding speed slows down, due to increase tack welds cross-sectional area and length, preheated if necessary. 　　6) Not be performed on a base material arc groove surface other than the need to fill the crater when extinction.

　　T-welded steel pipe containing Ni in the acidic environment, strong corrosion resistance in the presence of sulfuric acid or hydrochloric acid environment, the T-shaped welded steel pipe in the higher the content of Ni, the stronger the corrosion resistance. In the general environment, only in the T-shaped welded steel pipe to add Cr to prevent the phenomenon of erosion. The poor edge of the strip is another cause of the wrong side of the important reasons. Mass flow rate, heat flux, and structural parameters (helical curvature diameter and T / D ratio) on the saturated bubble boiling heat transfer coefficient in the vertical spiral tube were investigated. 　　 Welded steel pipe in the production, the wrong side occurs, its impact on many factors. In the production practice, often by the wrong side of the wrong side of the steel pipe downgrade. Therefore, it is necessary to analyze the cause of the spiral steel pipe misalignment and its prevention measures. 　　As the non-cutting ed...

　 　(1) Economic situation 　　From a global perspective, the demand for steel continues to grow with the development of the world economy. From a country's perspective, the development of the steel industry is also positively related to the economic development of the country. The speed of economic growth directly affects the society's consumption demand for steel, which affects the price of steel products. It can be said that the development of the steel industry is more affected by the economic cycle. When the national economy is in a period of rapid growth, the market demand for steel products is strong and prices are rising. When the national economy enters a period of adjustment, the price of steel products will also fall. 　 　(2) Cost status 　　At present, 2/3 of the world steel production and most of China's steel production are produced with iron ore as the basic raw material. Therefore, the change of iron ore price is a key factor affecting the production cost of...

　　In sizing rolling, seamless steel pipe diameter is compressed at the same time, the wall thickness will also change, changes in diameter and ovality of the pipe depends mainly on the amount of reduction sizing, and if appropriate adjustment of the sizing press lower volume and temperature, it can eliminate the ovality of seamless steel tubes, while maintaining a predetermined diameter, which also allows seamless improved mechanical properties. However, during the seamless steel pipe sizing, but also make the pipe residual stress, reduce its mechanical strength. 　　The residual stress is a common method of project. Mechanism of heat treatment to reduce the welding residual stress is a view that the yield stress of the material increases as the heating temperature decreases, the elastic modulus of the material has declined, so the temperature of the heat treatment process requirements, internal welding materials residual stress exceeds the yield strength of the material at this tempe...

　　The contents of the welded steel pipe welding inspection include the inspection of the materials, tools, equipment used in the whole production process, process and finished product from drawing design to product completed. It is divided into three stages: pre-weld inspection, inspection in welding process, finished product inspection after welding. According to whether damage the welded carbon steel pipe or not, test methods can be divided into destructive testing and non-destructive testing two categories. 　　 Pre-weld inspection 　　Pre-weld inspection includes the inspection of raw materials (such as base metal, electrodes, flux, etc.) and the inspection of welding structure design. 　　 Inspection in welding process 　　Inspection in welding process includes the inspection of welding process specifications, the inspection of weld size, the inspection of fixture conditions and structural assembly quality. 　 　Finished product inspection after welding 　　There are many methods...

　　In general, seamless steel pipe uses Brinell, Rockwell, Vickers three hardness indicators to measure the hardness. 　　1. Brinell hardness 　　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 　　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 from the hard...

　　What is the welding qulity of SSAW steel pipe ? It is the the degree to which the welding product meets the design technical requirements. Pipe manufacturer usually ensure the welding qulity of SSAW steel pipe by design quality, processing quality, quality inspection, post-weld treatment, etc., since the welding quality not only affects welding products's use performance and life, it also affects personal and property safety. 　　Welding quality usually appears as welding defects, that includes external defects and internal defects. External defects refer to excess height does not meet the requirements, welding tumor, undercut, crater, arc burns, surface pores, surface cracks, welding deformation and warping. Internal defects refer to cracks, not penetration, not fused, slag and porosity. 　　How to prevent the appearance of welding defects to ensure the welding quality? 　　1. Welding method should be suitable for the characteristics of components, and its economical efficiency ...

　　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...

　　In the production process of welded steel pipe, quality inspection is a very importance of foundation link. In general, pipe manufacturer will use optical microscope to test weld seam. Optical microscope is light waves to deal with visible and near-visible, bunching the beam to irradiate on the object, the imaging falls on the human retina, photosensitive film or other recording system, breaking the limitations of human physiology, the visual extension to The human eye can not tell the microscopic world. It is the most important optical precision instrument used to observe, record and study the fine structure of the object being examined. 　　High-frequency welded steel pipe is using the welding method to effectively connect the metal material. When pipe manufacturers produce high-frequency welded steel pipe (such as ERW steel pipe , LSAW steel pipe, spiral welded pipe), many factors in the welding process directly affect the weld metal and heat affected area of the macrostructure an...