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Although the conventional hot rolling stainless steel plate surface quality is poor, but in fact only for surface oxidation and finish low, other performance is good, such as plasticity, toughness and mechanical strength were higher, to corrosion of acid and alkaline gas and solution medium, and is also a kind of not easy rusty alloy steel material. If hot rolled stainless steel plate is washed and removed after pickling, it will become hot rolled and pickled stainless steel plate. This kind of plate can partly replace the application of cold rolled stainless steel plate, and the price is cheaper, and the popularity is relatively high. The hardness of hot-rolled stainless steel plate is relatively low, so it is easier to be processed, and the ductility is better. Most of hot-rolled stainless steel plates are moderately thick plates. The cold rolled stainless steel plate made from hot rolled stainless steel plate has higher strength and better surface finish. It is usually used as sheet metal and can be used as a stamping plate. And in the field of application, hot rolled stainless steel plates are also surprising. More areas of use include cold rolling raw plates, automobile steel, structural steel, weatherproof steel, high pressure vessel steel and so on. The following will be listed. First look at the structural steel and the hot rolled stainless steel plate can be used to produce common structural steel and welded structural steel, mainly used for steel structure parts, bridges, ships and vehicle production. In weathering steel, adding a certain amount of special elements in the hot rolled stainless steel plate, such as phosphorus, copper and carbon, the board will have excellent corrosion resistance and corrosion resistance, can be used to produce containers and special vehicles, can also be made into structures. The high strength hot rolled stainless steel plate with good welding performance for automobile structure can be used for the production of automobile structure. The hot rolled stainless steel plate can be made into the original plate of cold rolled stainless steel to make all kinds of cold rolled stainless steel plate products, such as color stainless steel plate, etc. In addition, the hot-rolled stainless steel sheet also has better processing performance and compressive strength, so it can also be used to make high-pressure gas pressure vessels filled with acetylene gas with less than 500 inner volume. In addition to the above applications, the hot rolled stainless steel plate itself has good corrosion resistance. After the corresponding processing technology, it can also be applied to the fields of food industry, petrochemical industry, aerospace and medical devices. Source: China Stainless Steel Plate Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Sometimes the cracking phenomenon of tensile stainless steel pipe, the scene appears persified, there are four kinds of common, respectively after tensile deformation, from the die exit occurs immediately after tensile deformation, impact or vibration occurs after tensile deformation, there is a section of time or in use. The main reasons are low ductility, high modulus of elasticity and high hardening exponent of stainless steel. The plastic deformation stage of stainless steel is relatively short from yield to cracking. Specific to the type of stainless steel, the cold hardening index of austenitic stainless steel is relatively high. Austenitic stainless steel is a metastable material. When deformation occurs, it will produce phase transformation, easy to form martensite structure, and martensitic phase is brittle, so it is easy to produce cracking. During plastic deformation, with the increase of austenite phase transformation, the content of martensitic phase will also change more, and the residual stress will also increase, resulting in a vicious cycle. During the processing, the stainless steel will also be more prone to cracking. So how do the stainless steel pipes prevent cracking in the process of use? In fact, the use of the appropriate lubricants for stainless steel pipe tensile effect is obvious. The lubricant can produce a layer of thin film with a certain ductility and ductility between the convex and concave dies, which is very beneficial to the drawing of stainless steel. Polyvinylidene fluoride film can also be used as lubricant for deep drawing parts of stainless steel pipes with large deformation and difficult forming. PVDF film has excellent tearing strength, certain toughness and ductility, and it is very convenient to clean up. Dangtu complex dry film, in the process of drawing the dry film deformation together with the blank, can always put the billet and die isolated, with thin film has its corresponding porosity and fibrous crack, so it can be stored in a certain oil, so that the film is a layer of dry film lubricant. This lubrication method can effectively separate the deformed stainless steel plate and the mold surface from each other, and the lubrication effect is very good. It is helpful for increasing the service life of the die and the qualified rate of the product. In addition, there are other simple ways, for example, white cast iron is used as the edge blank grinding tool. Because the oil storage property of white cast iron is good, it is easy to produce lubricant film, or the conical blank holder can also be used. It can also make the edges of the workpiece more smooth and remove the small opening gap, which can also effectively avoid the formation and expansion of the cracking. Source: China Stainless Steel Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

In the use of stainless steel plate, in order to ensure that the results meet the requirements, need to pay attention to board surface defects may occur, such as small crack, crack, crack, edge peak shaped inclusions and scabs all will have a negative impact on the surface quality of stainless steel plate, and ultimately reduce product quality. Below is the shape of the surface defect of the lower stainless steel plate. The shape of small longitudinal crack is on the surface of stainless steel plate, which has a length less than 200mm, the width is less than 3mm, and the depth is lower than 0.3mm. The peak crack will only appear at the 5-60mm of the surface of the surface of the stainless steel plate, which is perpendicular to the rolling direction, and the shape is similar to the “mountain peak”. The side line cracks mainly occur in the 20-80mm area at the edge of stainless steel plate, and the shape is multiple longitudinal cracks with different sizes. The feature is that the thicker the stainless steel plate is, the more serious the defect is. The distribution of inclusions and scarring of the comparative law, and by the side of the crack of billet inspection or flame peeling scratch flame cleaning and finishing operation after the presentation is very obvious. The formation of these defects is not a small, which is in the crystallizer longitudinal small impurities caused; peak shaped crack is more outer arc slab transverse corner crack cause subcutaneous; edge cracks are in rolling billet surface to form edges due to rollover; inclusion and scarring is finishing when the surface oxide slag do not clean up the cause. There are many ways to avoid the surface defects of the stainless steel plate, and the following are the following points. One is to regularly check the mould, especially water, there is no need to check into the small impurities, resulting in change of water quality. The second is to strictly control the equipment to ensure the maintenance of overage service, the segment in a timely manner, to prevent the occurrence of local segment does not turn to produce a deep scratch roll billet. The third is to carry out the zoning control of bending section water distribution, and dynamically control the corner temperature of the slab with different widths, so as to prevent the corner temperature from being brittle in the course of bending. It is also necessary to use the wide end face slab to produce large width steel plate and reduce the width of the stainless steel plate when rolling, so as to reduce the uneven deformation extent of the wide plate when rolling, and weaken the wide extent of the side line cracks produced by the stainless steel plate. It can also increase the temperature uniformity of the billet in the heating furnace, improve the heating process of the slab, reduce the temperature difference between the bottom and the bottom of the billet, and reduce the difference of the deformation resistance between the stainless steel workpiece and the lower part, so as to reduce the uneven deformation degree of the edge of the rolled piece. Finally, the finishing ability of the billet can be improved to prevent the two defects, such as incomplete cleaning of the slag, and the local depth burn. Source: China Stainless Steel Plates Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

When the stainless steel pipe is used for a long time, some oxidation phenomena will appear on the surface of the pipe. Good maintenance is only the extension of the oxidation. So why does the surface of the stainless steel pipe appear to be oxidizing? In fact, these surface oxidation is caused by corrosion of stainless steel pipes. The causes of corrosion on the surface of stainless steel pipe are mainly in the following aspects. One is that when the stainless steel pipe is in chlorine containing medium, the passivation film on the surface of the material is particularly vulnerable to destruction, which is due to the high potential energy of chlorine oxidation. Most of the time, the surface passivation layer of stainless steel pipe will be destroyed only in some areas, which is manifested by corrosion, forming tiny holes or pits, and this corrosion is often referred to as point corrosion. The rate of point corrosion increases with the increase of temperature, and increases with the increase of medium concentration. The corresponding solution is to use stainless steel passivation solution at room temperature for half an hour, which can significantly increase the corrosion resistance of stainless steel pipes about 5 to 20 times. The stainless steel passivation solution can be used circularly, and it is also easy to operate, which can greatly reduce the production cost. The second aspect is that the passivation layer on the surface of the stainless steel pipe is also easily damaged when the stainless steel pipe is produced and welded. When the heating temperature and time of welding in the production of stainless steel sensitization temperature (about 425-815 DEG C) area, chemical composition of stainless steel in the supersaturated carbon will first precipitated at the grain boundaries, and combined to produce the chromium carbide and chromium, and this time of carbon in austenite in the diffusion speed in chromium diffusion rate, leading to not because of formation of chromium carbide and loss of chromium in the chromium content of grain, grain boundary precipitation of chromium carbide with results continuously decreases rapidly, produce the chromium depleted zone, thereby reducing the corrosion resistance of the passivation layer. When the medium chlorine and other corrosive medium contact, it will cause the micro battery corrosion. Although corrosion occurs only on the surface of grain, it will rapidly penetrate into the intergranular corrosion of the organization, and the stainless steel pipe will be particularly prominent in the welding area. The third aspect is the stress corrosion crack. In a simple way, the stress in the stainless steel pipe is influenced by the joint effect of the crack embrittlement. But the environment that causes this situation is generally very complex. Not only light is tensile stress, but also the resultant force of residual stress produced in the production, welding, or processing of the stainless steel. Source: China Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

At present, there are mainly two kinds of stainless steel pipes smelting furnaces on the market. They are mainly refining furnaces and intermediate frequency furnaces. The quality of stainless steel pipes produced by them is obviously different, and the stainless steel pipes produced by refining furnaces are superior in performance. What is the refining furnace? Refining under standard atmospheric environment of stainless steel materials, stainless steel is blown into the molten steel in need of oxygen at the same time, but also blowing inert gas argon and nitrogen, in order to reduce the carbon dioxide content, to minimize the carbon content levels of the chemical composition of stainless steel materials, oxidation and blowing inert gas can effectively inhibit chromium the composition of stainless steel. So the advantages of the stainless steel pipes in the refining furnace are that the carbon content is very low, the impurity in the steel is very little, and the favorable elements such as chromium can be well preserved. Therefore, the stainless steel pipe produced by refining furnace has high ductility, which can completely meet the processing requirements of complex stainless steel pipes such as bending, bending, flaring and necking. Less impurities can also make stainless steel pipes have higher polishing performance. If the smelting furnace is formed by the AC magnetic field, a production process and the raw material heating furnace for steelmaking, its drawback is in steelmaking can not effectively reduce the carbon content of the chemical composition of stainless steel, unable to get rid of impurities, so the use of intermediate frequency furnace smelting production of stainless steel strip processed into stainless steel pipe ductility is poor, processing bending round, bending, expanding and necking of the performance is poor, the pipe impurity content in chemical composition is high, therefore can not meet the requirements of fine polishing processing. Although the production of stainless steel pipe furnace performance is relatively poor, but because of the price than the production of stainless steel refining furnace pipe cheaper such stainless steel pipe, stainless steel pipe production now if furnace stainless steel pipe still exist in the market, and both appear difference is not very obvious, but for product performance and price considerations, furnace production of stainless steel refining pipe or the best choice to use more reliable, rest assured. Source: China Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

At present, industrial stainless steel welded pipe is widely used in the application market of stainless steel at home and abroad. Among them, because of the difference of surface processing technology, the stainless steel industrial welded pipe is mainly pided into two kinds of welded pipe and polished welded pipe. The following are the principles and advantages and disadvantages of them. Stainless steel welded pipe with welded seam pickling is made by automatic welding. The process is single side welding to form two sides, and the weld is uniform and smooth. Because the acid pickling stainless steel welded pipe is made from the first grade stainless steel sheet, and the surface of the welded pipe is the same as the surface of the original plate. It is after polishing pipe molding using manual welding, then polished cast weld and surface passivation layer, so the surface brightness high stainless steel tube. Below is a comparison of the advantages and disadvantages of the stainless steel belt welded pipe and the polished welded pipe. First, the wall thickness of stainless steel welded pipe with weld acid pickling is more uniform and the pressure bearing performance is stronger. The wall thickness of the original pipe will be thinner, especially in the weld area, when the polishing pipe is artificially polished. The thinner the wall thickness of the weld zone, the lower its bearing capacity. Secondly, stainless steel welded pipe with welded seam pickling can ensure the integrity of austenitic stainless steel. Most stainless steel welded pipes are made of austenitic stainless steel as raw materials, such as 201, 202, 304 and 316 stainless steel, because the austenitic microstructure is not magnetic or weak magnetic. After polishing, the polishing pipe will result in small change in chemical composition, which makes the austenitic stainless steel have more obvious magnetism. The corrosion resistance of stainless steel welded pipe with weld acid pickling is stronger. The polishing stainless steel welded pipe eliminates the original passivation layer after pickling, so that the polishing pipe is also easy to rust in normal environment, and the corrosion resistance will weaken. The quality stability of stainless steel welded pipe with weld acid pickling is higher. The polishing welded pipe is because the raw materials are used in grade two or even recycled materials, and to cover up the defects of these materials on the surface of the polishing; even to reduce the cost of materials, but also the use of waste plates, so can not guarantee the quality stability of polishing welded pipe, the problem is very easy. Stainless steel welded pipe with welded seam pickling is more practical. Because of the mechanical properties, industrial pipe mainly used stainless steel pipe its corrosion resistance, but to the requirements of the surface of the pipe light degree is not very high, of course there must exclude decorative pipes and sanitary pipe, so many industrial pipe is not necessary to use polishing of stainless steel welded pipe of high cost and unstable performance. Source: China Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The strength of stainless steel is affected by various factors, and the most important and basic is the chemical elements added to the chemical composition. Therefore, the strength of the ferrite, martensite and austenitic stainless steel is different because of the differences in their chemical composition. Martensitic stainless steel has the characteristics of hardening by quenching, so it can obtain good mechanical properties by selecting the brand and heat treatment conditions. Martensitic stainless steel from the point of view, is Fe-Cr-C stainless steel. Then it can be pided into martensitic chromium stainless steel and martensitic chromium nickel stainless steel. In the quenching and tempering conditions of martensitic chromium stainless steel, the increase of chromium content will increase the content of ferrite, so the hardness and tensile strength will be reduced. In the annealing environment, low carbon martensitic chromium stainless steel increases slightly when the chromium content is increased, while the elongation will decrease slightly. Under the established conditions of chromium content, the increase of carbon content will lead to the increase of hardness and the decrease of the plasticity of the stainless steel. The purpose of adding molybdenum elements is to increase the strength, hardness and two hardening effects of stainless steel. After the low temperature quenching, the addition effect of molybdenum element is very obvious. In martensitic chromium nickel stainless steel, the content of delta ferrite in stainless steel can be reduced by a certain amount of nickel element, and the hardness of the material is maximized. In the ferritic stainless steel, when the chromium content in the composition of less than 25% ferrite will inhibit the formation of martensite, so as to enhance the material strength of the chromium content will gradually decrease; chromium content is greater than 25% because of the effect of solid solution strengthening, stainless steel material strength to be improved. The increase of molybdenum content can make it easier to obtain ferrite, which can promote the precipitation of alpha phase, sigma phase and X phase, and enhance its strength after solid solution strengthening. But at the same time, the sensitivity of the material notch will be enhanced to reduce the toughness. After increasing carbon content in austenitic stainless steel, the strength of the material will be improved because of its solid solution strengthening. The chemical composition of austenitic stainless steel is the addition of molybdenum, tungsten, niobium and titanium on the basis of chromium and nickel. Because the metallographic structure is a face centered cubic structure, it will have high strength and creep strength at high temperature. And because the linear expansion coefficient is high, so the thermal fatigue strength is weaker than that of ferrite stainless steel. Source: China Stainless Steel Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

It is well known that the vast majority of stainless steel materials are suitable for cold forming. Austenitic stainless steel itself is not magnetic, but cold processed austenitic stainless steel will have strong magnetic properties, especially those made of austenitic stainless steel, such as head, elbow and so….. Why will the austenitic stainless steel suddenly appear to be magnetic after cold processing? The main reason is that most of the microstructure of austenitic stainless steel is mostly metastable austenite, so the more accurate term should be the metastable austenitic stainless steel. When the metastable austenite stainless steel for cold forming, part of austenite in the steel will transform into martensite, and maintain a coherent and original austenite, produce diffuse phase transition in a very short period of time by shear form, which is called the martensitic transformation induced by martensitic transformation or deformation. In a stainless steel microstructure of martensite is usually a martensite centered cubic structure with dense Hugh six party structure of martensite two forms, including alpha martensite with magnetic characteristics, martensite organization has no magnetic characteristics, but only when the nickel content is relatively high, will form. Martensite. So when some of the common austenitic stainless steels are transformed from austenite to martensitic structure, magnetic properties will be formed. The stability of austenite is determined by the corresponding chemical composition, and the transformation of martensite caused by processing is also related to the intensity of the process. If materials are used for common uses such as food industry, magnetism does not affect the use of products, so some standards are usually allowed to exist. But if the magnetic presence is not allowed, the corresponding preventive measures should be done. According to the causes of martensite formation and the influencing factors, the main preventive measures are the following. The first is to prepare for the processing of stainless steel plate in the content standards within the allowable range of austenitizing elements to enhance tissue; secondly it can be upgraded materials, such as the use of 316L and 310 nickel content relatively large stainless steel materials; also can optimize the processing technology of stainless steel; solution heat treatment measures can be taken, it can completely eliminate the phenomenon of magnetic and the work hardening. But the cost of this method is relatively high, and it has a great impact on the size and deformation of the products. Finally, it is necessary to strictly avoid the influence of unnecessary mistakes on the quality of products according to the relevant production standards. Source: China Stainless Steel Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

There are two main types of stainless steel pipes, which are stainless steel seamless pipes and stainless steel welded pipes. It is known by the name that the former has no weld seam, the latter is mainly welded and formed, and their specific production process differences and their respective characteristics are described below. Stainless steel seamless pipe The stainless steel seamless pipe is simply a kind of long strip of stainless steel which is hollow inside the pipe and has no seams around the body. The manufacturing process sequence is smelting, ingot, rolling, sawing, peeling, perforating, annealing, pickling, up ash, cold drawing, cutting, pickling and warehousing. The features of the seamless steel pipe have three main aspects. From the process point of view, on the one hand is the seamless steel pipe wall is thicker, its economy and practicability is high, wall thickness of the thinner the processing cost is higher; on the other hand is the production process to determine the limitations with seamless stainless steel pipes, seamless steel pipe, the accuracy is generally low: the thickness of the pipe wall will not even, inside and outside of the pipe surface brightness is lower, the high cost of fixed length, and sometimes on the inside and outside surface black spots difficult to remove; besides detection and shaping of stainless steel seamless pipes must be processed offline. So only in high pressure, high strength, mechanical structural treatment to fully reflect the advantages of seamless steel pipe. Stainless steel welded pipe Stainless steel welded pipe can be called welded pipe. It is a stainless steel pipe which is formed by using stainless steel plate or with the curling of the machine and mould. The production process sequence is stainless steel plate, strip, molding, welding, induction bright heat treatment, internal and external weld treatment, shaping, sizing, eddy current testing, laser diameter measurement, pickling and storage. There are two main features of the welded stainless steel pipe. On the one hand, its production mode is continuous online production. The thicker the wall is, the higher the investment will be for the unit and the melting equipment. The more economical and practical it will be, the more discount it will bring. The smaller the wall thickness of stainless steel welded pipe, the lower the input-output ratio. On the other hand, the advantages and disadvantages of the stainless steel welded pipe will be greatly influenced by the technology. The ordinary welded steel pipe has high accuracy, uniform wall thickness, high brightness inside and outside the pipe, and it can also arbitrarily measure the size. Therefore, the welded pipe stainless steel pipe has better beauty and economy in the application of high precision, medium and low pressure fluid. Source: China Stainless Steel Welded Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

In order to enhance the surface quality of stainless steel pipelines, optimization of the surface morphology and application of structure, reduce the energy level and the number of dielectric layers, need to do some processing on stainless steel pipeline system, mainly pided into mechanical drawing, mechanical grinding, polishing, pickling and passivation, feather cloth light burning blunt, sub electrochemical polishing and electrochemical polishing. Mechanical drawing is used to increase the roughness of the surface by the plug of the plug. It can improve the surface structure of the stainless steel pipeline, but it will not optimize the other aspects. This is the most basic surface treatment process, and the roughness of this method also lays a good foundation for further surface treatment process. Mechanical grinding is the use of precision grinding method to increase the surface roughness, which can optimize the surface structure, but will not improve the shape and other aspects. Fabric decoration is polished stainless steel industry commonly used to increase the brightness of the surface of the way, although this process Ra value is good, but in the electron microscope can still see a lot of cracks, the actual surface area becomes larger, the local will be separated from the ferrite and martensite structure. The surface of the pipeline is mixed with a lot of impurities, such as abrasive particles. Because the use of the polishing paste, a lot of energy will be in the original formation of the depression, leading to the increase in the number of media. Such pipelines are often not used in sensitive corrosive media, such as optoelectronics and biopharmaceuticals. After pickling or passivation, stainless steel pipelines will not enhance the surface roughness of the material, but it can remove the residual abrasive particles and reduce the energy level, but it can not reduce the number of interlayers. The light burning passivation process refers to the hydrogenation or vacuum condition of stainless steel pipeline by high temperature heat treatment, so as to eliminate the internal stress, but also generate a passivation film on the surface of the pipelineline, which can optimize the structure and reduce the energy level, but does not increase the surface roughness. Asia is a kind of electrochemical polishing a surface treatment based on BA stainless steel plate, which is a slight electrolytic polishing process, to try to reduce the surface area, thick passivation film, thereby increasing the corrosion resistance and improve surface morphology, reduce the energy level. After such surface treatment, the stainless steel pipeline is not very high in brightness, but the surface quality is greatly improved, and it will not form particles and reduce the composition of iron and iron oxide on the surface. Electrochemical polishing process is achieved by electrochemical polishing, which can greatly increase the surface morphology and structure, and minimize the actual surface area of stainless steel pipelines. The surface of the pipeline is a closed, very thick chrome oxide film. The energy is close to the normal level of the stainless steel alloy, and the quantity of the medium will be reduced to a minimum. Source: China Stainless Steel Pipelines Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel welded pipe is a pipe made of stainless steel plate or strip crimping after forming and welding, simple production process efficiency, low cost and variety of specifications, but generally low strength than seamless steel pipe. However, with the continuous progress of production technology, the quality of stainless steel welded pipe is getting better and better, in many respects it has replaced the original seamless steel pipe. According to the form of weld, two kinds of welded pipe can be pided into straight welded pipe and spiral welded pipe. The production process of the former is relatively simple, the production efficiency is high, the cost is low, and the development is faster. The latter strength is usually higher than the former, and its raw material source is wider. But compared with the straight seam stainless steel pipe of the same length, the weld length increases more and the production speed is slower. Therefore, most of the small caliber welded pipe is welded with straight seam, and most of the large diameter welded pipe is welded by spiral welding. Below is the following example. Low pressure fluid transport with galvanized stainless steel pipe, mainly used to transport water, gas, air and heating steam, hot water and other low pressure fluid. Such stainless steel pipes can be pided into ordinary galvanized steel pipes and thickened galvanized steel pipes according to wall thickness. According to the end of pipes, they are pided into stainless steel galvanized stainless steel tubes and threaded galvanized stainless steel pipes. Common carbon steel wire bushing is used mainly as a kind of steel pipe used in electrical installation engineering, such as industrial and civil construction, installation machine equipment and so on. The straight welded stainless steel pipe is a kind of steel pipe which is parallel to the weld and the stainless steel tube. Generally, it is pided into public welded steel pipe, thin-walled tube of electric welding and cooling pipe of transformer and so on. The spiral submerged arc stainless steel welded pipe for pressure fluid transportation is made of hot rolled stainless steel coil as the tube blank. It is welded by normal temperature spiral forming, and is welded by double side submerged arc welding. It is used as the spiral seam steel pipe for pressure fluid transportation. The stainless steel pipe has strong bearing capacity, better welding performance and safety reliability. The stainless steel pipe has a large diameter and high transport efficiency, and it can save a lot of pipeline investment. The spiral stainless steel welded pipe used for pile is made of hot rolled stainless steel coil as the tube blank, which is formed by the spiral molding at room temperature, using double side submerged arc welding or high frequency welding. The main purpose is stainless steel pipe for wharf or bridge foundation. Source: China Stainless Steel Welded Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

In recent years, the rapid development of production technology and equipment technology level of global stainless steel pipe, stainless steel pipe international advanced production features is the use of new equipment, new technology, automatic control and NDT to improve product quality and yield, in the domestic stainless steel welded pipe and seamless steel pipe production technology have also made great progress, but compared with the international advanced level there is a large gap. Below to look at the production technology of several stainless steel pipes. Three step process for steelmaking and continuous casting The production of stainless steel pipe billet by “three step” steelmaking and continuous casting can effectively increase the quality of stainless steel pipe billet and reduce the cost. The process of using electric furnace for melting, MRP – L converter and oxygen gun fast decarbonization, VOD vacuum furnace end deep decarburization, the starting point is that the advantages of AOD and VOD two kinds of production process of the combination of play, can solve the large consumption and processing time for the shortcomings of AOD argon and refractory materials, a short time with the aim of low cost. Hot extrusion process Hot extrusion process is the main production process of hot – working stainless steel seamless steel pipe. With the continuous development of technology, some hot rolled steel pipe sets can produce stainless steel pipes, but the extruding unit is the main production unit of stainless steel seamless steel pipe. Compared with rolling and rolling, it is characterized by three direction compressive stress in the deformation process of stainless steel. In this optimal stress state, the stainless steel pipes with high deformation resistance can obtain a better quality of the internal and external surface and the metallographic structure. Cold rolling production in cold rolling Cold processing stainless steel pipes mainly use cold rolling (cold drawing) combined production technology, cold rolling mills and cold drawn machines develop towards high-speed, high-precision, long journey and multi line. Most of the stainless steel pipes are finished in the form of cold processing. So people pay more attention to cold processing equipment. Cold – drawing, cold rolling, cold – rolling and cold drawing are the three kinds of cold – processing technology. Cold rolling and cold drawing are used in most of the stainless steel pipes. The main and secondary relations are cold rolling and cold drawing. The modern cold rolling mill can also achieve large reducing and large wall reduction, and the deformation of the rolling mill is mainly achieved on the cold rolling mill. Multi line, high speed and full automatic are the better development direction of the current cold drawing machine. Various welding processes The progress of welding technology has speeded up the development of stainless steel welded pipe production, and the application of various welding methods further improved the welding quality and productivity. At present, the main methods for welding stainless steel used in industry are tungsten arc welding, high frequency welding, plasma welding and laser welding. The highest application frequency is argon arc welding and high frequency welding. Light heat treatment process Concerning the heat treatment process of stainless steel pipes, the non oxidation continuous heat treatment furnace with protective gas is widely used abroad for intermediate heat treatment and final product heat treatment. Because of the ability to get no oxidation of the bright surface, in order to eliminate the traditional pickling process. The use of this heat treatment process not only optimizes the quality of the stainless steel pipe, but also solves the problem that the acid cleaning is easy to pollute the environment. Source: China Stainless Steel Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)