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How to get rid of surface stains of cracking tube follow the steps below: The first step is to clean, we must first petroleum cracking tube surface oil, dirt, grease, and some other substances removed.  The second step is naturally acid, generally speaking, there are two pickling treatment, a chemical treatment, another treatment method is electrolysis, which can be handled in two ways petroleum cracking tube surface cleaning clean, but chemical pickling is a pipeline anti-corrosion measures.  The third step is necessary to use the tool to the surface of the oil cracking pipe polished, although the effect may not be very good polish, but this procedure is also indispensable. The final step is to make the surface of petroleum cracking tube jet, one can remove some of the dirt, the second is to make the roughness of petroleum cracking tube more evenly.  For petroleum cracking tube defects formed on the surface there are many, but certainly there are a lot of different reasons, the specific form of the crack is different, often found defective for its appearance on petroleum cracking tube we can see, the main reason for its main form by the following points. In fact, for the production process, the emergence of various drying phenomena of its raw materials for steelmaking summer rainy season or when it will produce up to steel gas content’s sake. In the process, the ingot when heated due to heating of the air bubbles are burned through, it will have more cracks after the rolling, which will meet the petroleum cracking tube relatively thin, dense and sizes, its length ranging from cracks, these things collectively referred to as hairline, this is a defect. So the cause of the surface oil cracking tube defects are many, so we have to remedy. After oil cracking pipe handling, appearance becomes smoother, more beautiful. Although after the rust will not affect the use again, but if we do the work in advance, so do not bother it. We buy petroleum cracking tube among the first to note that it is not a strong corrosion resistance, have a longer life does not have to select a high-quality petroleum cracking pipe products that can reduce our future work a lot of trouble.

Due to the wide range of application of shaped steel tube, which promotes the rapid development of the production of shaped steel tube. The development of shaped steel pipes is the main link of product variety, including section shape, material and performance, a shaped steel tube factory (workshop) for a variety of products, often living in all metal pressure processing factories and mines. A special-shaped steel tube plant, foreign products amounted to more than 8000, in a factory of our country turns out to be production of cold drawn round pipe, compared with a single product, after nearly ten years accept shaped steel tube set loan, products section, specifications and varieties development to 2100, almost every year to increase of new varieties of hundreds to hundreds. It is not the same as the general steel pipe plant products more and more specialized and the main target on the production index of the production is not the same. shaped steel pipe production is characterized by many varieties, small batch, mobile ling. Of course, it does not exclude some of the more mature, the need for a larger variety of professional production. Shaped steel tube material not only various carbon actinium, structural steel, low alloy steel and high alloy gold actinium, stainless steel, high-temperature and gold, tungsten, molybdenum, titanium, beryllium and other metal and alloy. Extrusion method is one of the effective methods to produce shaped steel tube. It is suitable for producing various sections and materials. In recent years, many hundreds of tons to 3150 tons of extruding machines have been established successively. This is not enough, in order to production of a wide variety of special-shaped steel tube, must also have a variety of means of production. Therefore, in recent years, our country in the original only on the basis of cold drawing machine, Wei new roll drawing, extrusion, hydraulic, spinning, rolling, rolling and rotary forging dozens of production equipment and continuous improvement and creation of new equipment and technology. In addition, technical strength training and production technology research. Is also a key to improve the production of shaped steel tube. The prospects for the development of the production of special steel tube is very broad, vigorously carry out the metal deformation, the correct calculation method, give full play to the production potential, improve the quality of products such as theoretical research is imperative. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

High frequency welding is a welding process in which the heat source used to melt the joining surfaces is obtained from high-frequency (HF) alternating current (ac) resistance heating. Steel weld gap control Adjusting the amount of pressing the squeeze roll is maintained across the weld flush with the opening angle of 7 degrees or less, the gap control between 1-3 mm. Weld control is too large, it may appear poor welding, weld cracking produce incomplete fusion or weld control is too small, due to the excessive heat, weld likely to cause burning, molten metal splash, build-up is too large, affecting the quality of welding. (Splatter reasons: melt extrusion tube side, the internal pressure is greater than the surface of the weld steam pressure)  Regulation of high-frequency induction loop position Induction coil placement should be in the same center line pipe, induction loop front roll center line distance from the squeeze, squeeze rollers under the premise does not burn , depending on pipe size as close, too far away when the heat affected zone width, weld strength will decrease. Coupled induction coil more tightly as possible, the selection of a single circle, should be equal to the width of the induction coil pipe diameter. Optional lap or two laps great impact on high frequency oscillation frequency and output efficiency.  Impedance (also known as magnet) position control Impedance is a group or a special magnet whose cross-sectional area of 70% attributable to the inner diameter of the steel pipe section. Its role is to strengthen the electromagnetic induction, eddy currents concentrate the heat weld edges. Sometimes add some magnets outside the weld, can also play a supporting role. Magnet permeability on temperature is large, the lower the temperature the higher the permeability. Magnet should be placed in the heating section V-zone, squeezing front roll center position, the position of the magnet and the magnetic permeability of welded directly affect the efficiency and weld quality.  Heat output control High-frequency power input to the heat pipe weld area called the input of heat, lack of heat input welding speed is too fast, can not reach the edge of the pipe welding temperature, the formation of incomplete fusion or penetration of the crack but excessive heat input when welding speed is too slow, too prone to burning, so that the weld breakdown, causing metal splash, the formation of pores. By adjusting the speed of the high-frequency voltage or welding method, the size of the control input of heat, the steel pipe weld neither appear nor appear incomplete penetration welding wear phenomenon, reaching the welding quality requirements.

Usually, according to the purpose of the steel pipe and working condition is different, dealing with the allowable deviation of the size of the steel pipe, surface quality, chemical composition, mechanical properties, process performance and other special performance and so on different technical conditions were put forward. Generally seamless steel pipe is used to transport oil, gas, water and other fluid pipeline and manufacture of various structure parts, dealing with its mechanical properties such as tensile strength, yield strength and elongation to do sampling test. Duct usually works under the condition of pressure, also asked to do hydrostatic test and flaring, flattening and crimping process performance test. For large long distance crude oil, refined oil, natural gas pipeline steel pipe is increased the carbon equivalent and welding performance, low temperature impact toughness, severe corrosion condition, the stress corrosion and corrosion fatigue strength and corrosion environment and so on. Ordinary boiler tube is used in the manufacture of all kinds of structure of boiler superheated steam pipe and boiling water. High pressure boiler tube is used in the high voltage or super high pressure boiler superheated steam pipe, heat exchanger, and is used in the high pressure pipe of the equipment. The thermal technology equipment in steel tube are working in different conditions of high temperature and high pressure, should guarantee the good surface state, mechanical properties and process performance. Is to test its mechanical properties, flattening and water pressure test, high pressure boiler tube also asked to do about the inspection of the grain size and more strictly nondestructive testing. Machinery with the size of the seamless steel pipe according to the requirements must have higher precision, good mechanical properties and surface condition. Such as bearing tube of high wear resistance, uniform organization and strict inner and outer diameter tolerance. Except for general mechanical performance inspection items, also want to do low power, fracture, annealing organization (spheroidizing, net light, strip), non-metallic inclusions (oxide, sulfide, dotted, etc.), such as decarburization layer and its hardness index test. Be used in the chemical fertilizer industry in the normal pressure high-pressure seamless steel tube is 2200 ~ 3200 mpa, the working temperature for – 40 ~ 400 ℃ and corrosive environment chemical medium (such as ammonia, methanol, urea, etc.). High-pressure seamless steel tube should have strong corrosion resistance, good mechanical properties and surface state. In addition to do mechanical properties, flattening and water pressure test, should according to different types of steel accordingly reduced corrosion test, grain size and more strictly nondestructive testing. Be used in oil drilling, geology with steel pipe under high pressure, alternating stress, work under corrosive environment, therefore, should have a high level of strength, and anti-wear, torsional and corrosion resistant properties. According to the different grade of steel should be tested for tensile strength, yield strength, elongation, impact toughness and hardness test. To be used in oil well casing, tubing and drill pipe, more detailed pision of the steel grade, class, and is suitable for different environment, geological condition by the users to choose their own higher requirements of additional technical conditions, to meet the specific requirements of the different. Been used in chemical, petroleum cracking, aviation and other machinery industry of various kinds of stainless heat acid tube in addition to the mechanical properties and water pressure test, but also specifically between works corrosion test, flattening, flaring, NDT test, etc. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Generally speaking, the welded steel pipes are pided into general welded pipe, galvanized welded pipe, oxygen welding pipe, metric system welded tube, transformer tube, welding thin wall pipe and spiral welded pipe etc. Generally, Controlling the shape of the weld is by adjusting welding current, arc voltage, welding speed, welding wire extension, welding wire Angle and welding head offset.  1, the welding current on weld penetration and bead height is very significant. The larger the current, the greater the penetration, the weld height is greater. 2, the arc voltage and wire elongation has a greater impact on the weld width. The greater the Arc voltage, the larger the wire elongation.  3, the welding speed, the smaller the bead width, penetration depth is smaller.  4, the wire angle has great influence on the weld shape. Welding wire is in the direction of deviation from the vertical, weld penetration increased width decreases; if the wire deflection departure from the welding direction, the weld penetration depth decreases and the width increases.  5, the welding head offset is welded to the pipe center point of the horizontal radial distance, the shape of the weld is also great. This is the spiral submerged arc welded pipe -specific issues. Spiral pipe in the spiral tube for welding under a state of movement, there is a circumferential steel rotating movement, which will cause the flow of molten iron bath, the impact of weld. Select the appropriate offset to help weld with satisfactory appearance and shape, if the offset is greater and the bead height is smaller , as well as side to side mobility trends within the weld and weld middle sag larger trend.

The annealing of the stainless steel elbow is one of the factors that determine the quality of the stainless steel elbow. If we grasp this part, we will improve the production efficiency. The stainless steel elbow is heated to a certain temperature and heat for a while, and then slowly cooling it, called annealing. The annealing process of the stainless steel elbow is to heat the steel to the temperature of the phase transformation or part of the transformation, and the heat treatment method after heat preservation is slow. Annealing of stainless steel elbow, in order to eliminate the defects, improve the organization to make component uniformity and refine the grain and improve the mechanical properties of the hot pressing stainless steel elbow and reduce the residual stress; at the same time, reduce hardness and improve the plasticity and toughness, improve the machining performance. Therefore, the stainless steel elbow annealing in order to eliminate and improve the previous process of the organization and the residual stress, and to prepare for the subsequent process, the annealing is a semi – finished heat treatment, also known as pre heat treatment. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Speaking of 304 stainless steel and 201 stainless steel, we certainly no stranger, but in the eyes of many consumers, the difference between the two is not directly with the naked eye can be judged. Some businesses shoddy, the use of 201 stainless steel instead of 304 stainless steel, not only will cause economic losses to customers, more serious may also lead to security incidents. So we introduce these two kinds of stainless steel material characteristics, to distinguish between 304 stainless steel and 201 stainless steel. The characteristics of 304 stainless steel 304 stainless steel is a common material in stainless steel, processing performance, high toughness, widely used in all walks of life. 304 stainless steel is the most important element is Ni, Cr, the specific requirements are determined by the product standards, the industry generally determine that as long as the Ni content> 8%, Cr> 18%, can be considered 304 stainless steel, so 18/8 stainless steel The resulting name. 304 stainless steel is a common material in stainless steel, the density of 7.93 g / cm3. Resistant to 800 degrees of high temperature, with processing performance, high toughness characteristics, widely used in industrial and furniture decoration industry and food and medical industry. For example: 304 stainless steel pipe, 304 stainless steel pipe fitting, 304 stainless steel flange, etc The source of 200 series stainless steel 200 Series stainless steel was born in World War II, it is the beginning as a 300 series of stainless steel alternatives in the United States successfully developed. As a result of the war, nickel at the time of the country’s strategic material, and thus the strict control of the country, the United States a serious shortage of nickel supply, so the United States took the lead in the development of manganese instead of nickel austenitic stainless steel new material. 201 stainless steel as a typical representative of the 200 series, also has a series of typical shortcomings. Chromium content of less than 18% and low content of nickel can not reach the balance of the formation of ferrite, for 200 series stainless steel chromium content down to 13.5% ~ 15%, in some cases even down to 13% to 14% Corrosion resistance can not be compared with 304. 201 stainless steel contains a lot of manganese, it can not be used for food and pharmaceutical industries. I poured a couple tablespoons of plain white vinegar (which is of course, quite acidic) into two pots—my All-Clad 2-quart saucepan, and another generic stainless steel pan I had lying around. I also put some of the vinegar into a glass cup as a control. After a few minutes, I taste-tested the vinegar from each.The All-Clad vinegar? Tasted exactly like the vinegar in the glass cup. But the vinegar in the cheap, generic stainless pan tasted like metal. Blech. The taste is still in my mouth as I type! I definitely will be sticking with the All-Clad for my stainless steel cookware, personally. And, I’m pretty convinced my vinegar test is a decent way to determine the reactivity of your stainless steel. Try it out on yours and see if it passes! But if it doesn’t, I wouldn’t freak out over this. Just be mindful about cooking with very acidic things like tomato-based sauces and stuff, and avoid storing these foods in your stainless steel. Related: How safe is your stainless steel? Test the quality with vinegar! If it tastes metallic, it’s leaching heavy metals. The distinguish methods of 304 stainless steel and 201 stainless steel Compared to 304 stainless steel, 201 stainless steel nickel and chromium element content is lower than 304, and because 201 stainless steel contains a lot of manganese, 304 stainless steel manganese content of less than 2%, used to say no manganese, and strictly called low manganese. However, the color point of view, 201 stainless steel manganese element, the color will be darker than 304, 304 to light some, but it is not easily distinguishable to the naked eye. 1. Because of the difference in nickel content, 201 stainless steel corrosion resistance and acid-base resistance are lower than 304. And because the carbon content of 201 is higher than 304, so 201 to 304 than the hard and brittle, a little steel, more easily cracked, while the 304 is better toughness. If you use a hard knife in the 201 stainless steel surface scratched the surface will have obvious scratches, but the scratches 304 will not be particularly evident. 2. Because 201 stainless steel contains manganese, if long-term in the wet and salty air will rust, but 304 stainless steel will not rust. Some people may say that 304 stainless steel will rust, it is probably not 304 stainless steel. Household stainless steel doors and windows, staircase handrails, some relatively dry environment can use 201 stainless steel. If the long-term in a humid environment, like the sink, kitchen and so you need to select 304 stainless steel, more corrosion-resistant. 3. Now on the market there is a detection of stainless steel reagent, as long as a few drops can be a few seconds What is the difference between the material Stainless steel, the principle is very simple: the elements contained in the material reacts with the reagent to produce colored material. Reagent itself is very low cost, and accurate and convenient, is a good way to distinguish. 4. You can also use professional testing equipment – spectrometer detection. This method is the fastest and most accurate, but the instrument is expensive. If the material is very important, you can find a special testing company, they will have a spectrometer. I believe that through the above description, how to distinguish between 304 stainless steel and 201 stainless steel, we have more understanding, and hope to help you in the practical application of convenient choice.

The residual defects in erw steel pipe ultrasonic testing is an important reason for failure of the weld, causing defects missed is inappropriate due to a probe parameter selection, disturbing wave effects and burr flaw echo echo does not distinguish between such a variety of factors.  Steel ultrasonic testing to detect delamination defects can reduce the subsequent generation of weld defects; weld inspection by the online automatic ultrasonic testing, offline auto detection, manual ultrasonic testing is completed. Online automatic ultrasonic testing set after the internal and external deburring, ultrasonic probe temperature by several groups for real-time monitoring of the weld, the weld quality real-time monitoring is an effective means of welding seam produced incomplete fusion, scraping the inner seam is not timely in addition to other issues, which can be in this position detected in a timely manner, contribute to the timely adjustment of the inner seam welding process and scraping device, greatly reducing the generation of weld defects, to eliminate the appearance of a large number of substandard products. Offline ultrasonic testing of the weld is the ultimate intrinsic quality detection means, which is to ensure the quality of the main ERW pipe weld points, offline pipe probe positioning can guarantee to more accurately detect defects. Automatic ultrasonic defect is detected, manual ultrasonic testing is generally used to further identify. Automatic ultrasonic testing process layout and manual ultrasonic probe and probe selection process is basically the same.

Stainless steel is typically heat treated based on the improvement of processability, elimination of internal stresses and strengthening of the ductility and corrosion resistance of metals, or the generation of hard structures capable of tolerating abrasion and high mechanical stresses. Heat treatment of stainless steel is mostly carried out under controlled conditions to avoid carburization, decarburization and scaling on the metal surface. Heat treatment techniques include annealing, case hardening, precipitation strengthening, tempering, normalizing and quenching. The following describes the heat treatment process basically includes most of the mainstream of steel heat treatment process. Annealing of stainless steel Stainless steel will be heated to a certain temperature and a fixed time insulation, and then slowly cooling, known as annealing. Annealing of stainless steels are to heat the steel to the phase transition or part of the phase transition temperature, through the insulation after the slow cooling heat treatment method. The purpose of annealing is to eliminate defects in the organization, to improve the organization so that the composition of the grain homogenization and refinement to improve the mechanical properties of steel to reduce residual stress; at the same time reduce the hardness, improve the plasticity and toughness, improve the cutting performance. So the annealing is to eliminate and improve the former procedures left after the organization of defects and internal stress, but also for the follow-up process to prepare, it is semi-finished annealing heat treatment, also known as pre-heat treatment. Annealing of stainless steels is carried out at temperatures greater than 1040°C, but certain types of steel can be annealed at very controlled temperatures of below 1010°C while considering fine grain size. The process is maintained for a short interval, in order to prevent surface scaling and control grain growth. Normalizing of stainless steel Normalizing is heated to above the critical temperature of stainless steel, it is all around for uniform austenite, and then in the air to cool naturally. It can improve comprehensive mechanical properties of stainless steel, but with less ductility for the same composition than full annealing. Quenching Quenching is a process of cooling a metal at a rapid rate. This is most often done to produce a martensite transformation. To harden by quenching, a stainless steel must be heated above the upper critical temperature and then quickly cooled. Depending on the alloy and other considerations (such as concern for maximum hardness vs. cracking and distortion), cooling may be done with forced air or other gases, (such as nitrogen). Liquids may be used, due to their better thermal conductivity, such as oil, water, a polymer dissolved in water, or a brine. Upon being rapidly cooled, a portion of austenite (dependent on alloy composition) will transform to martensite, a hard, brittle crystalline structure. The quenched hardness of a stainless steel depends on its chemical composition and quenching method. Cooling speeds, from fastest to slowest, go from brine, polymer (i.e. mixtures of water + glycol polymers), fresh water, oil, and forced air. However, quenching a certain steel too fast can result in cracking. If the percentage of carbon is less than 0.4 percent, quenching is not possible. Tempering Tempering is a process of heat treating, which is used to increase the toughness of iron-based alloys. Tempering is usually performed after hardening, to reduce some of the excess hardness, and is done by heating the metal to some temperature below the critical point for a certain period of time, then allowing it to cool in still air. The exact temperature determines the amount of hardness removed, and depends on both the specific composition of the alloy and on the desired properties in the finished product. For instance, very hard tools are often tempered at low temperatures, while springs are tempered to much higher temperatures. Most applications require that quenched parts be tempered. Tempering consists of heating stainless steel below the lower critical temperature, (often from 400 to 1105 ˚F or 205 to 595 ˚C, depending on the desired results), to impart some toughness. Higher tempering temperatures (may be up to 1,300 ˚F or 700 ˚C, depending on the alloy and application) are sometimes used to impart further ductility, although some yield strength is lost. It should be noted that not all steels will respond to all heat treatment processes, summaries the response, or otherwise, to the different processes. Anneal Normalise Harden Temper Low Carbon <0.3% yes yes no no Medium Carbon 0.3-0.5% yes yes yes yes High Carbon >0.5% yes yes yes yes Low Alloy yes yes yes yes Medium Alloy yes yes yes yes High Alloy yes maybe yes yes Tool Steels yes no yes yes Stainless Steel (Austenitic eg 304, 306) yes no no no Stainless Steels (Ferritic eg 405, 430 442) yes no no no Stainless Steels (Martensitic eg 410, 440) yes no yes yes Heat treatment of stainless steel surface (1) surface hardening: the steel surface is quickly heated to above the critical temperature, but the heat has not yet had time to reach the heart before the rapid cooling, so that the surface layer can be quenched in the martensite, while the heart does not occur Phase change, which achieved the surface hardened and the heart of the same purpose. Applicable to medium carbon steel. (2) Chemical heat treatment: refers to the chemical element of the atom, with the help of atomic diffusion of high temperature, it penetrated into the surface layer of the workpiece to change the chemical composition and structure of the workpiece surface layer, so as to achieve a specific surface layer of steel The required organization and performance of a heat treatment process. In accordance with the different types of infiltration of elements, chemical heat treatment can be pided into carburizing, nitriding, cyanide and percolation metal four. Carburizing Carburizing refers to the process of infusing carbon atoms into a steel surface layer. But also to make the surface of low-carbon steel workpiece with high-carbon steel surface, and then after quenching and low temperature tempering, the workpiece surface layer with high hardness and wear resistance, and the central part of the workpiece is still maintaining the toughness of low carbon steel and Plasticity. Nitriding Austenitic stainless steels can be surface hardened by nitriding. This process has very limited application, as the stainless steel core is soft and has very low strength for heavy applications. Another major limitation is that the nitrided steel is less resistant to corrosion when compared to the original stainless steel. Cyanide Also known as carbonitriding, refers to the steel in the same time infiltration of carbon atoms and nitrogen atoms in the process. It makes the steel surface with carburizing and nitriding characteristics. Infiltration of metal Refers to the process of penetration of metal atoms into the surface layer of steel. It is the surface layer of steel alloy, so that the workpiece surface with some alloy steel, special steel characteristics, such as heat, wear resistance, oxidation resistance, corrosion resistance. Production is commonly used in aluminizing, chromizing, boronizing, silicon infiltration and so on. The above is the mainstream of steel, especially heat treatment process of stainless steel. With the continuous progress of technology, heat treatment process is also constantly updated.

TIG welding (Tungsten Inert Gas arc Welding), also known as tungsten inert gas welding. TIG welding is also used for thicker sections root pass welding, the main welds surfacing. The heat source is a DC TIG welding arc, the working voltage of 10 to 15 volts, but the current up to 300 A, the workpiece as the positive electrode, the tungsten electrode welding torch as the cathode. The inert gas is usually argon. The process of TIG welding: Inert gas fed through the torch, the arc weld pool on the sides and form a shield. To increase the heat input, generally within the argon with 5% hydrogen. However, in the ferritic stainless steel welding, argon within not hydrogenated. Gas consumption per minute, about 8 to 10 liters. In the welding process, in addition to inert gas is blown from the welding torch, the best protection is also blown into the weld seam from the back with a gas. Classification TIG manual welding pided by mode of operation, semi-automatic and automatic welding categories. GTAW, the torch movement and adding filler wire entirely by hand operation; semi-automatic TIG welding, torch movement by manual operation, but the filler wire by wire feeder automatic feeding; Automatic TIG arc welding, such as workpiece stationary arcing motion, then the welding torch mounted on a small car, the car or walking and filler wire can be used cold or hot filament yarn way to add. Hot wire means increasing deposition rate. Some occasions, such as sheet metal welding or weld backing, sometimes without adding filler wire. The three welding methods, GTAW most widely used, semi-automatic TIG welding is rarely used.

Socket weld pipe fitting is an important branch of high pressure pipe fittings, in mechanical, chemical, petroleum, construction and other industries play an important role and value, socket weld pipe fitting with different varieties and function, different types of pipe plays a different role, their use range and the use of the environment is also different. In the United States has a long history, the earliest origin, at present our country’s technology relative to the western developed countries is still relatively backward, want to reach the international advanced level must also strengthen the production technology and the introduction of advanced production equipment. Socket weld pipe fitting is smaller shape product using a small forging hydraulic press by repeated forging can produce qualified blank. Bearing the pipe blank dimensions and machining residual value is designed by the research and development personnel according to the actual situation and habit selected, refer to the relevant standards. Socket weld pipe fitting pieces of parting surface to add some draft Angle, so that the socket weld pipe fitting can smoothly take out from the mold cavity after stamping. Factors affecting the draft Angle design is more, can adopt the method of combining the automatic design and interactive selection dial mode slope value is determined. Usually, outside take 8 degrees slope, slope within 12 degrees. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel angle bar as a common steel, with a wide range of markets. Due to more varieties of specifications, the manufacturer’s quality standards vary, to some extent, there are good and bad situation, resulting in a lot of users in the choice of stainless steel angle bar material problems. This article simply summarizes the purchase of stainless steel angle bar material quality assessment methods and common points of attention, for reference. stainless steel angle bar commonly used in metal components, connectors and the basic framework of the structures. Has a good weldability and mechanical stress intensity, and have good plastic deformation properties. Procurement How to judge the quality of stainless steel angle bar? First, the stainless steel angle bar through the naked eye to determine the appearance of qualitative Stainless steel angle bar for the appearance of the quality of industry standards and has a clear requirement, covering the stratification, scarring, cracks, and many other specific provisions, and secondly, the standard also focuses on geometric deviation made a series of provisions, Curvature, edge width, edge thickness, vertex angle, theoretical quality Through the naked eye carefully observed, supplemented by a number of routine testing tools, and control the implementation of standards, the user is easy to judge from the hands of the hands of the stainless steel angle bar whether the product is a standard qualified products, qualified manufacturers at the factory has a more stringent quality Process. Products can stand the test. At least in the appearance and size will not have too much deviation, the appearance of observation is a more effective primary test method. For example, a 2B surface 201 and 304 of the stainless steel angle bar material, through observation can be found in the 201 color slightly dull, while the 304 surface of the material is shiny, we can use the palm pressure on the surface of the material, we can find deep fingerprints Of the 201, compared to lighter handprint is 304 material. However, such methods need to sum up experience, suitable for many years of veteran practitioners. Simple material judgments can to some extent prevent the supplier shoddy, reduce losses. Second, through the detection reagent to determine stainless steel angle bar Conditions of the purchaser can be through special chemical reagents on the stainless steel angle bar component analysis, which is the most scientific detection methods. stainless steel angle bar from the chemical composition point of view tend to the general structure of rolled steel series, testing indicators are C, MN, P, S four test standards. According to the characteristics of different grades, the chemical content also has some differences, for example: C <0.22%, Mn: 0.30-0.65%, P <0.060%, S <0.060%. For these chemical composition we can control the GB223, JISG1211-1215, BS1837 and other methods to detect, so as to ensure the quality of stainless steel angle bar. The actual operation of the process, the purchaser may not have the opportunity to purchase the stainless steel angle bar to conduct a comprehensive chemical analysis and testing. More common practice is through the purchase of conventional stainless steel testing reagents, fast and intuitive stainless steel angle bar for chemical reaction testing. For example, a reagent drops to the surface of stainless steel angle bar, 201 change dark brown, 304 red, you can initially determine the material properties. Of course, the specific chemical reaction depends on reagent instructions, can not be generalized. Third, judging by the price of stainless steel angle bar As stainless steel angle bar procurement staff, must be fully familiar with and understand the varieties classification and purchase price of the stainless steel angle bar. Pay close attention to the steel market, when the supplier offer price significantly lower than the market average price stainless steel angle bar, that in itself is not reasonable, there is a doubt. Or poor quality, the material does not conform to the standard, or informal manufacturers of low grade products. If the price of the same steel grade is large, it must carefully consider whether or not the quality problem. To summarize, we want to purchase to qualified stainless steel angle bar, first of all, from the product appearance against industry standard judge whether the products meet quality requirements, the second conditional strict chemical parameters testing can be used to determine the standard material, no conditions of conventional chemical reagent can be used in the field of material simple judgment. In this way, can the maximum guarantee we can procurement to the best quality stainless steel angle bar.