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In the process of stainless steel processing, the welding of 2205 duplex stainless steel is a very test welding technology. This article will pay attention to the welding process of this kind of stainless steel. People usually call for the second generation of double phase stainless steel standard duplex stainless steel, its composition is characteristic of ultra low carbon and nitrogen, the typical composition of the steel is 22% chromium, 5% nickel, 0.17% nitrogen, compared with the first generation of double phase stainless steel, 2205 stainless steel to improve nitrogen content, enhance the concentration of chloride ion in acidic medium the higher the resistance to stress corrosion and pitting corrosion resistance. Nitrogen is a strong element of austenite formation. When added to duplex stainless steel, it can not only improve the strength, but also do not damage the plasticity and toughness of stainless steel, and also inhibit the precipitation of carbides. The microstructure of 2205 duplex stainless steel is remarkable. In the greenhouse, the austenite and ferrite in the solid solution of steel are about half of each, both of which have the characteristics of two-phase structure. The retained ferrite stainless steel small coefficient of thermal conductivity, corrosion, crevice and chloride features, stress corrosion of austenitic stainless steel has good toughness, brittle transition temperature is low, the resistance to intergranular corrosion, mechanical properties and welding performance. In addition, the performance is outstanding. The yield strength and stress corrosion resistance of dual phase stainless steel are nearly 1 times higher than that of austenitic stainless steel, and the material can be effectively saved under the same pressure grade condition. The coefficient of linear thermal expansion of austenitic stainless steel is lower than that of low carbon steel. Therefore, duplex stainless steel is suitable for joining with carbon steel, and its engineering significance is great. But forging and cold stamping are inferior to austenitic stainless steel. The weldability of duplex stainless steel 2205 is good, and the sensitivity of welding cold crack and hot crack is smaller. Generally, there is no need to preheat before welding and no heat treatment after welding. Because of the higher nitrogen content, the single-phase ferrite tendency in the heat affected zone is smaller. When the welding material is selected reasonably and the welding line energy is controlled at the time, the welding head has good comprehensive performance. The thermal crack sensitivity of 2205 duplex stainless steel is much lower than that of austenitic stainless steel. This is because the nickel content is not high, easy to form low melting point eutectic impurities very few, it is difficult to produce low melting point liquid film. In addition, the grain does not grow rapidly at high temperature. In addition, the main problem of duplex stainless steel welding is not in the weld, but in the heat affected zone. Due to the thermal cycling, the heat affected zone is in a fast cooling non equilibrium state. After cooling, more ferrite is retained, which increases the corrosion tendency and the susceptibility to hydrogen induced cracking (brittleness). In the process of duplex stainless steel welding, the microstructure of weld metal and heat affected zone undergo a series of changes under the action of thermal cycling. The microstructure of all duplex stainless steels is composed of ferrite at high temperature, and austenite is precipitated during cooling. The precipitation of austenite is affected by many factors. The mechanical properties and corrosion resistance of the duplex stainless steel welded joint are affected by the proper proportion of the welded joint, so the welding is centered on how to ensure the duplex structure of the welded joint. When the amount of ferrite and austenite is close to 50%, the properties are good and close to the properties of base metal. If this relationship changes, the corrosion resistance and mechanical properties of the duplex stainless steel welded joint shall be reduced. Duplex stainless steel 2205 best 45% ferrite content is too low, the ferrite content is less than 25% will result in strength and resistance to stress corrosion cracking ability should be decreased; the high ferrite content greater than 75% will be detrimental to the corrosion resistance and impact toughness decrease. The first phase stainless steel welding factors affected the proportion is mainly depends on the balance between the welding joint of ferrite and austenite, which is influenced by the content of alloying elements in steel, and by the filler metal, welding heat cycle, protective gas. The most important feature of duplex stainless steel welding is that the welding thermal cycle has an influence on the microstructure of the welded joint, and the phase transformation will occur in both the weld and the heat affected zone, which will affect the performance of the welded joint to a great extent. So the multipass welding is good, has the effect of heat treatment on subsequent weld bead front, weld metal ferrite further transformed into austenite and become dominant in two phases of austenite; heat affected zone adjacent to the weld in the austenite phase also increased accordingly, and can reduce the grain refinement of ferrite carbide and from the nitride and grain boundary precipitates. The welding process number is the welding line energy, also plays the key role to the dual phase organization balance. Because duplex stainless steel is 100% ferrite at high temperature, if the line energy is too small, the heat affected zone cooling rate is fast, the austenite is not enough to precipitate, and the excessive ferrite will remain cool under the greenhouse. If the line energy is too large, the cooling rate is too slow, although you can get sufficient austenite, but it may also cause the heat affected zone of ferrite precipitated grains and sigma phase harmful metal phase, resulting in the formation of joint embrittlement. To prevent this from happening, the best measure is to control the welding line energy and the interlayer temperature, and fill the metal with filler metal. Source: China Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The pipeline will produce gas phase dielectric liquid; liquid medium will produce gas, eccentric reducer and concentric reducer are the difference lies in the purpose of reducing is achieved; and reached the discharge of liquid or gas. So according to your process requirements of discharged liquid or gas to choose the direction of concentric and eccentric reducer reducer. First of all, the common function of the two is to change the diameter, that is, the need to change from one specification to another. However, due to the use of the environment and the different media, there are concentric and eccentric points, just like the three pass. Concentric reducer will not say, the following about eccentric reducer: 1, gas accumulation pipeline, because the gas in the pipeline will be accumulated upward, so we must use the top flat bias to prevent the gas can not be ruled out; 2, some impurities or liquid will sink to the top of the pipe, so must use bottom flat eccentric, prevent accumulation, can not be ruled out Since it is variable diameter, then of course, it needs to be used in the place where the specifications need to be changed. Otherwise, you can’t even change it. If you change the place casually, it may cause waste of material or insufficient traffic However, there is no use of concentric reducer restrictions; eccentric reducer in the pump and other equipment will be set up, the specific situation. Do not say concentric reducer, that is, to change the caliber of the use of. Eccentric reducer is pided into top flat and bottom flat. Top flat, usually used in liquid pipelines to prevent gas accumulation in the pipe. Bottom flat is generally used in the gas pipeline, to prevent the accumulation of liquid in the pipeline, there is to prevent the accumulation of impurities in the size of the head. There is the pump imports are generally flat top, in order to prevent cavitation. Source: China Reducer Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The use and maintenance of the stainless steel elbow requires a lot of attention, which requires users to use it according to certain methods, and use and maintain in accordance with accurate and reasonable methods. Precautions are as follows: 1. the stainless steel elbow, long-term storage should be timely check, often appear the processing surface should be clean, remove dirt, neatly stored in a dry indoor drafty place, it is strictly prohibited stacking or in open air. Always keep the drying and ventilation of stainless steel elbow, keep the device clean and tidy, and store it according to the accurate storage method. 2. When installing, the stainless steel elbow can be directly connected to the pipe on the tube, and installed according to the location used. In general, can be installed on the pipeline at any position, but need to test for easy manipulation, should pay attention to the flow direction of medium by the stainless steel elbow is high, the longitudinal disc below stainless steel elbow can only be installed horizontally. The stainless steel elbow should be attentive to the seal during installation to prevent the leakage and affect the normal operation of the pipe. 3. When the ball valve, globe valve and gate valve of stainless steel elbow are used, only open or fully closed, do not allow to adjust the flow, so as to prevent the sealing cover from erosion and accelerate wear and tear. The gate valve and the upper thread globe valve have a backsealing device, and the handwheel is screwed to the top position to prevent the leakage of the medium from the filling. 4. Use handwheel for stainless steel elbow, do not use lever or other tool to avoid damage valve parts. The handwheel turns clockwise to be closed, and vice versa. The use of children should be reasonable, ensuring accurate use of methods and means. 5. The bolts of the packing gland of the stainless steel elbow should be tightened on average and should not be held in a crooked state so as not to hurt the stem movement or cause the leakage. 6. In the process of use, the stainless steel elbow should always be kept clean, and the transmission thread must be lubricated in time. When the fault is found, it should be stopped and used immediately to find out the reason for the failure. Source: China Stainless Steel Elbow Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The reducer is a kind of pipe fitting for pipe diameter. It is usually used to press the forming process for reducing diameter pressing, diameter pressing or reducing diameter. A. Diameter/diameter formation The reducer forming process of the reduced-diameter steel tube is to insert the tube billet into the forming mould with the diameter of the reducer, and the metal is moving and shrinking along the cavity of the die cavity by pressing the axial direction of the steel tube. According to the size of the diameter of the reducer, it can be pided into one crushing forming or multiple crushing forming. In the process of reducing or expanding deformation, the cold pressure or thermal pressure is determined according to different materials and varying diameters. Normally, use cold pressure as far as possible, but the condition of serious processing hardening, thick wall thickness or alloy steel materials should be used with hot pressure. B. Stamping forming In addition to using steel pipe as the raw material to produce the different diameter steel pipe, some specifications of the diameter steel tube can be used for the production of sheet metal stamping process. The die shape of the drawing is designed according to the surface dimension of the diameter of the tube, and the blanking drawing of the steel plate is formed with the punching die. Characteristics of stress distribution (1) the bending moment caused by the difference of the area pressure difference between the inner pressure and the diameter of the reducer causes the large end to be relatively open and the small end is relatively shrinking; (2) the inner surface of the inner surface of the eccentric reducer and the central surface of the center of eccentricity are the most stress. Source: China Reducer Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel stub end is the method of stamping the edge or hole edge of a semifinished product or semi-finished product into a vertical edge along a certain curve. When the edge of the line is a straight line, the flanging deformation becomes curved, so it can be said that bending is a special form of flanging. In addition, according to whether the wall thickness of the vertical edge is thinned, it can be pided into thinned flanging and invariable thin flanging. According to the shape of the blank and the edge of the workpiece, it can be pided into inner hole (round hole or non circular hole), flanging, flat outer edge flanging and curved flanging. But when bending, the deformation of the blank is limited to the fillet part of the curved curve, while the flanging part and the edge part of the blank are deformed areas, so the flanging deformation is more complicated than the bending deformation. According to the nature of deformation, flanging can be pided into extension type, flanging and compression type flanging. The common characteristics of stretch flanging is the tangential stress to tensile deformation in cutting under the effect of elongation, ultimate deformation degree is mainly affected by the deformation zone cracking limit compression flanging is common, except near the metal area near the root radius of the vertical side bending deformation, produces shear compression deformation to the rest of the deformation region of the stress to the pressure in the cutting effect, its deformation characteristics belong to compression deformation, stress state and deformation characteristics and drawing the same ultimate deformation degree is mainly affected by the deformation wrinkling limit flanging are compression flanging. Flanging method can process more complicated shape and good stiffness of three-dimensional parts, in stamping production and other assembly parts, such as vehicle bus, bus door pedal pressure plate flanging iron flanging, automobile door, motorcycle fuel tank, flanging hole flanging metal plate small screw hole flanging. Flanging can replace the drawing process of some complicated parts and improve the plastic flow of material so as not to break or wrinkle. In order to reduce the number of processing and save material, the method of replacing the first drawing and the later cutting is adopted. Source: China Stainless Steel Stub End Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Manufacturing process of stainless steel pipe fittings Blanking The main materials used for pipe fittings are pipes, plates and bars, and the blanking method is selected according to the material characteristics and the shape of the billets used in the products. The shape, size, and other requirements of the billet are performed in accordance with the process specifications for different products. The pipe material commonly used under the band sawing machine or bow cutting, gas cutting, plasma cutting machine. For the plate material, commonly used methods are cutting, plasma cutting, punching punch. For the bar, material commonly used under the band sawing machine sawing machine for cutting, punching and cutting or bow. Forming (welding) Forming is an indispensable process for the manufacture of all pipe fittings. Since the forming processes of different products are different and require longer space, they will be described in section 15.2.4. Here, a brief introduction to the heating and welding included in the part forming process is presented. A.. Heating In order to meet the requirement of material deformation in forming process, the billet must be heated during the forming process. Heating temperature usually depends on material and process. Hot bend or hot bending forming, intermediate and high frequency induction heating method is usually adopted, but also the use of flame heating method. The heating method is continuous heating with the forming process of the elbow or the bent pipe, the tube blank is heated in the movement and the forming process is completed. Hot pressing elbow, hot pressing three pass or forging forming, usually using reverberatory furnace heating method, flame heating method, induction heating method or electric furnace heating method, etc.. This heating is the process of heating the tube to the desired temperature before putting it into the mold and pressing or forging it. B. welding Fittings with weld includes two kinds of situations, one is fitting for welded pipe, the pipe manufacturing factory, the welded pipe forming process and forming process of the seamless tube is basically the same, the pipe forming process does not include the welding process; the other is the factory to complete the required weld pipe forming process by fitting. Such as a pressing after elbow, assembly welding with rolling steel plate after welding tube and then pressed into three links etc.. The welding methods of pipe fittings are manual arc welding, gas shielded welding and automatic welding. The welding procedure shall be worked out by the manufacturer to guide the welding work, and the welding procedure qualification shall be evaluated according to the relevant specifications so as to verify the correctness of the welding procedure regulations and evaluate the welding ability of the welders. Engaged in pipe welding welder who should pass the quality and Technology Supervision Department of the examination and obtain the corresponding qualification certificate shall be engaged in relevant steel welding work (according to the regulations, some industries for welding fittings in some industries to achieve industry regulations of welders and welding technology evaluation, such as ship pipe welding to obtain the corresponding classification welders and welding process qualification). Heat treatment Heat treatment process is an important part of pipe manufacturing. Through the heat treatment step heating, insulation and cooling, eliminate work hardening and forming process of the residual stress and deformation of metal defects, metal fittings, organizational performance change after forming, return to the state before the deformation or the performance can be improved and enhanced. The commonly used heat treatment equipment is the reverberatory furnace, the electric stove, and so on. The usual control way is the thermocouple in the furnace is connected to the control device of the temperature time automatic recorder by the sensor. The standards for heat treatment in different pipe fittings are not the same. Not all the fittings are to be deformed after heat treatment, usually for low carbon steel pipe, the final forming temperature not lower than 723 DEG C (recrystallization temperature), without heat treatment, because in the condition of the final state basically is normalizing state, below this temperature or above 980 degrees should undergo heat treatment; alloy steel pipe or stainless steel material whether by cold forming or hot forming, heat treatment shall be carried out. Routine inspection of heat treatment is done by hardness test. Surface treatment The surface pipe fitting usually adopts sand blasting, shot blasting, polishing, pickling and other methods to remove surface rust, scratches etc., make the products reach the smooth surface, meet the subsequent processing and inspection requirements. The surface hardness of the pipe surface treated by shot blasting will increase slightly. Cutting process Cutting is the completion of the end of the pipe welding, structural size, shape and position tolerances processing. For some pipe products, cutting also includes internal, external diameter processing. Cutting through a special machine or tool; for oversized fittings, when existing machine capacity can not meet the processing requirements, can also be processed by other methods, such as method of cutting with large diameter elbow after grinding. The appearance and size inspection of pipe fittings are usually performed after cutting. The nondestructive testing Nondestructive testing is an important procedure to test the defects that may occur during the processing of materials and fittings. The requirements for nondestructive testing are specified in most pipe fittings standards, but the requirements are not the same. In addition to meet the product standard and order requirements for nondestructive testing, some of the more stringent quality control of manufacturing plant according to the materials, processing technology and internal quality control regulations requirements of nondestructive testing, to ensure the quality of manufactured products. In actual work, the determination of the unqualified grades of pipe fittings shall be made in accordance with the ordering requirements or standards. Because the pipe surface is basically the original pipe, plate or forging state, nondestructive testing on tube surface quality (MT, PT), if there is no clear grade requirements according to grade II, but no matter how qualified grade regulations, defects of the interlayer and the crack is not easy to judge the depth shall be deemed unqualified. For the nondestructive testing of the internal quality of pipe fittings (RT, UT), if there is no definite grade requirement, the radiographic inspection shall be conducted at the level II (e.g., weld detection), and ultrasonic testing shall be of class I. In order to prevent the possible defects of the product during the heat treatment, the final nondestructive test of the pipe shall be carried out after heat treatment. The nondestructive testing of pipe fittings factory in our country usually adopts the JB/T 4730 specification. The personnel engaged in nondestructive testing shall obtain the corresponding qualifications in accordance with the relevant provisions. The surface protection The surface protection of carbon steel and alloy steel pipes are usually made by coating, and the method of passivation for stainless steel after pickling is adopted. The main purpose of the surface protection of pipe fittings is corrosion protection, and the appearance of the products is also beautiful. In general, the ordering party makes specific requirements for surface protection, and the manufacturer completes the protection of the pipe surface according to the requirements of the ordering party. The sign Logo is an integral part of the product, is the basis for achieving traceability requirements. Generally, the contents, methods and regulations are specified in the product standard. The contents of a pipe include the manufacturer’s trademark or name, material grade, specifications, and other requirements of the order. Mark method includes permanent marks, such as stamping, carving, electric erosion; non permanent marks, such as printing, label etc.. To the other In addition to the conventional manufacturing process, to control the quality of raw materials, manufacturers should also complete the inspection of raw materials, to ensure that the material used is correct; in order to satisfy special requirements or ordering materials, should also be such as microstructure, intergranular corrosion, ferrite inspection and testing, to ensure that the the products meet the requirements of customer use. Source: China Stainless Steel Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The chemical composition of 316 stainless steel plate is mainly of the phosphorus, which is less than 0.035%, or 0.03% sulfur, 10.0-14.0% nickel, 16.0-18.5% chromium, 2.0-3.0% molybdenum element. The performance is also good, the tensile strength (Mpa) 620 MIN, yield strength (Mpa) 310 MIN, elongation (%) 30 MIN, area reduction (%) 40 MIN, the density is 8.03 g/cm3. 316 stainless steel plate by adding alloying elements molybdenum, so its corrosion resistance, resistance to atmospheric corrosion resistance and high temperature strength is especially good, can be used in harsh environment, the work hardening performance good, also has good high temperature strength, products of nonmagnetic solid solution state, another glossiness good appearance of the cold rolled sheet but its price is higher compared with 304 stainless steel. It is mainly used to make seawater or highly corrosive environment. The 410 stainless steel plate, as the representative steel of martensitic steel, is not suitable for application in strict corrosive environment, although the strength is high. Its processing performance is excellent, the main purpose is knife edge, machine part, oil scouring device, bolt, nut, pump rod, 1 kind of tableware. Difference between 316 stainless steel plate and 410 stainless steel plate Daily use of the most stainless steel model is 304, 316 stainless steel, the main difference is that in the chemical composition of the two 316 molybdenum, and broad consensus is 316 stainless steel corrosion resistance is better, more than 304 under the environment of high temperature corrosion resistance. Therefore, 316 stainless steel components are usually used in high-temperature operating environments. However, there are exceptions. In the sulfuric acid environment, the high temperature can not be made of 316 stainless steel. Otherwise there will be big problems. Learn machinery are studied thread, remember to prevent thread killed below high temperature circumstance, need to apply a black solid lubricant, the molybdenum disulfide (MoS2), it has two conclusions, first of all, molybdenum is a kind of high temperature resistant material, such as molybdenum crucible is gold in the crucible of molten, second molybdenum easily and high reaction generated sulfide sulfur ions. So no stainless steel can withstand any corrosion. At the end of the day, stainless steel is a piece of impurity steel, although it is more resistant to corrosion than normal steel, but it can react with other materials as long as it is steel. 316 stainless steel plate is a lot of more phyletic, mainly pided into polished stainless steel plate, light stainless steel plate, precision surface of stainless steel plate, stainless steel plate, 6 k BA surface of stainless steel plate, 2 b surface of stainless steel plate, surface of stainless steel plate, 8 k mirror stainless steel plate, ultra-thin stainless steel plate, in the thick thick stainless steel plate, stainless steel plate, super thick stainless steel plate. Thickness of stainless steel plate: thin plate (0.2mm- 4mm), medium plate (3mm- 30mm), thick plate (4mm- 60mm), special thickness plate (60-115mm). With the development of economy, the use of 316 stainless steel plate is also more and more, in our daily life is closely related to stainless steel, but a lot of people know the performance of the stainless steel is not much, maintenance of 316 stainless steel plate and seldom know. Not familiar with the people think that stainless steel is never rust, actually, is only good corrosion resistance of stainless steel, the reason is that the surface form a layer of passivation film, it is in the nature exists in the form of more stable oxide. In other words, although the stainless steel is different depending on the conditions of use, the oxidation degree is different, but it is eventually oxidized. This phenomenon is usually called corrosion. The exposed metal surfaces in the corrosive environment all have electrochemical reactions or chemical reactions, which are corroded uniformly. 316 stainless steel plate surface corrosion resistance of passivating film weak parts, also on self-excited pitting, formed by the reaction, resulting in holes, add to the chloride ion have close, can produce very strong corrosive solution, the speed of the accelerated corrosion reaction. In addition, the corrosion cracking of intergranular corrosion in stainless steel can destroy the passivation film on the surface of the stainless steel plate. Therefore, the stainless steel surface must be regularly cleaned and maintained, which will keep the stainless steel plate beautiful and extend the service life. Source: China Stainless Steel Plate Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel has a unique corrosion resistance, it can react with the oxidant to form a thin and dense oxide film used to prevent the oxidation reaction into a further occurrence. For other types of metal pipe, almost no passivation function, which is stainless steel pipe material corrosion resistance than the general one of the main reasons for metal pipe. Stainless steel pipe fittings are recognized as healthy materials, widely used in food processing and transportation pipeline, including the pharmaceutical industry, beverages, brewing and so on. Stainless steel pipe material performance is superior, effectively reduce the cost of transportation, in the long process of transport will not scale, smooth inner wall, while transporting low energy consumption, is the lowest cost of water pipes so far. First, the classification and use of stainless steel pipe fittings 1, stainless steel pipe fittings classification Stainless steel pipe, stainless steel pipe, stainless steel tube, stainless steel tube, stainless steel pipe, stainless steel pipe, stainless steel pipe, stainless steel pipe, stainless steel pipe, stainless steel pipe, According to the connection method can be pided into socket-type stainless steel pipe fittings, threaded stainless steel pipe fittings, flange stainless steel pipe fittings and welded stainless steel pipe four categories. Stainless steel elbow for pipe turning place; flange for the pipe and pipe interconnected parts, connected to the pipe end, stainless steel tee for three pipe collection place; stainless steel pipe for four pipe collection Place; stainless steel reducer for the different diameter of the two pipes connected to the place. 2, the use of stainless steel pipe Stainless steel fittings can be used to ensure carbon steel surfaces by means of paints or oxidation resistant metals (eg zinc, nickel and chromium), but, as is known, this protection is only a film. If the protective layer is damaged, the following steel will start to rust, resistance to air, steam, water and other weak corrosive media and acid, alkali, salt and other chemical erosion medium corrosion of steel. Stainless steel pipe fittings with the most is the pressure vessel and chemical aspects. General refinery equipment factory has a lot of demand. Other aspects, such as chemical, food, beverage, pharmaceutical and other industries can be applied. Its main widely used in petroleum, chemical, medical, food, light industry, mechanical instruments and other industrial pipelines and mechanical structural components. Second, the characteristics of stainless steel pipe fittings 1, life expectancy Stainless steel tubing has the longest service life. Analysis of the use of stainless steel from abroad, stainless steel water pipe life of up to 100 years, at least 70 years, as long as the life of the building. 2, corrosion resistance One of the most prominent advantages of stainless steel tubing is its excellent corrosion resistance, which is the best in a variety of tubing. Because stainless steel can be passivated with the oxidant, in the surface to form a layer of tough and dense chromium oxide oxide protective film Dr2O3, effectively prevent the further occurrence of oxidation. The other metal pipe, such as galvanized water pipes, brass passivation capacity is very small, which is galvanized copper tube corrosion resistance is far less than the key reason for stainless steel pipe. Stainless steel does not have the same corrosion as carbon steel, the use of no need to protect the coating; the use of stainless steel water pipes, the chemical composition of water is not limited, because the stainless steel in a variety of oxygen content, temperature, PH and hardness of the water are very good Corrosion resistance; stainless steel water pipes can withstand high flow rates, even if the flow rate is greater than 40 m / s, still maintain a very low corrosion rate, not more than 0.003 mm / year, especially for high-rise water supply. 3, heat and insulation Stainless steel tube thermal conductivity is brass tube 1/25, is the ordinary steel pipe 1/4, especially for hot water delivery. The most commonly used stainless steel in the water industry is 304 and 316 stainless steel, which meet the vast majority of water treatment and transmission conditions. 4, strength The strength of the material determines whether the water pipe is strong and reliable, safe and reliable. And safe and reliable construction of water is the most important requirements. In the case of external shocks, the possibility of leakage of stainless steel water pipes is extremely small. High-rise water supply system working pressure is generally greater than 0.6Mpa; pipe pressure requirements are higher. Thin-walled stainless steel pipe due to excellent mechanical properties, can withstand high water pressure, up to 10Mpa above, especially for high-rise water supply. Third, how to distinguish between true and false stainless steel pipe fittings 1, compare items tooth front and teeth distance: 2, the standard naked eye to see the front teeth sharp, teeth from the uniform and bright. 3, feel: ivory smooth, deep processing standards, the core is even wall, flow flow. 4, the factory before mechanical processing, the surface without folder, debris. 5, low carbon content, corrosion resistance, oxidation resistance, toughness, strong anti-pressure. 6, rough, tooth front unfavorable and thick, teeth from the non-standard, tooth front damage, easy to leak 7, thread can not see the shiny, dark feel bad, 8, core distortion, wall thickness uneven, easy to plug the fluid after. 9, rough, the surface is not processed, easy to be oxidized 10, high carbon content, not rot, toughness is poor, weak pull resistance. Fourth, the installation of stainless steel pipe fittings skills Stainless steel pipe fittings installation techniques are the following nine note: 1, stainless steel material lifting, can not be in direct contact with other metals, should be added to the board or rubber sheet and other non-metallic materials. 2, pipe cutting is not allowed to use ordinary wheel cutting, should be used for stainless steel grinding wheel or plasma cutting. 3, stainless steel pipe and pipe fittings welding should be carried out on the inside of the weld argon protection. 4, starting arc and arc, starting arc using back welding method, the arc should be filled with craters. Arc must be completed in the groove, prohibited in the pipeline, pipe base material arc and arc. If the arc and the arc found at the pores, cracks and other defects should be promptly handled clean. 5, stainless steel pipe, pipe fittings and stainless steel pipe, pipe fittings and non-stainless steel pipe, pipe fittings, welding of the butt joint primer welding before and inside the cavity should be filled with argon protection, in order to TIG welding. 6, multi-channel multi-layer welding from the arc, the arc should be staggered with each other. 7, stainless steel continuous welding, the interlayer temperature does not exceed 60 ℃. 8, pipe connection welds at the weld, after welding to be pickling and passivation treatment. 9, stainless steel pipe water pressure test on the water temperature and water quality have certain requirements, the water temperature shall not be less than 5 degrees Celsius; water chloride content had to be greater than 25Pmm. Source: China Stainless Steel Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel pipe fittings, especially the three links, elbow and size of the first class in pipeline engineering construction in the process of using more and more common, this is largely due to its forming good, strong compression ability, simple welding form etc, to ensure the bearing capacity of the pipe, so in the process piping engineering especially in petrochemical and flammable and explosive pipe of high temperature and high pressure. The reasonable use of stainless steel pipe fittings and the quality of stainless steel pipe fittings are of great importance. Is solid, especially in the process of pipeline design and installation of high temperature and high pressure in the petrochemical industry and flammable and explosive pipeline engineering, both from the design selection and processing manufacturing, until the construction installation and inspection of each link, the design and manufacturing and installation contractor personnel should strictly, ensure its selection, material, manufacture, installation and inspection of quality, otherwise the device will cause in the process of construction and production loss. First from the construction process, we find that the quality of the stainless steel pipe fitting is mainly in the following aspects. 1. The wall thickness of stainless steel pipe fittings is uneven The wall thickness of stainless steel pipe is mainly occurred in the most deformed part of the stainless steel pipe. The wall of the elbow is thin on the other part; The wall thickness of the pipe and stainless steel pipe fittings is different. The provisions of the relevant national standards. The thickness of the wall thickness of the stainless steel pipe should be no more than 1, 2 and 5 of its nominal thickness, but in the field measured, some of the thickness of the wall thickness decreased to 20 ~ 30. For this type of problem, it is often difficult to detect the use of the usual calipers, which can only be detected by the use of ultrasonic thickness gauges. 2. Excessive hardness The result of the problem of excessive hardness is mainly due to the process of heat treatment after forming. The solution is to use the correct heat treatment process for another heat treatment. This problem can generally be solved 3. Defects caused by materials and processing Such problems are the most harmful to the safety of the device. It’s a hassle to check. The factors that produce defects are more and more complicated. It has the defects of the material itself, the problems of processing and manufacturing process, and the defects caused by the improper heat treatment process. Source: China Stainless Steel Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

In the actual operation of the pickling process of stainless steel plate, will inevitably encounter some problems, such as stainless steel plate surface defects caused by pickling, if you do not know the cause of these defects and solutions that will make the same mistake next time. Here is to introduce these defects and causes. Pickling bubble The bubble is because acid and acid exposed stainless steel board reacts to generate hydrogen, with the formation mechanism refers to the stainless steel plate and acid to produce chemical reaction, generate some hydrogen atoms, it penetrates into the crystal lattice of stainless steel, and the deformation, deformation after the hydrogen diffusion in metal to more among them, a part of hydrogen atoms and molecules through the stainless steel plate, escaping from the acid liquid, part of the hydrogen atom molecule in the lattice distortion of “micro hole” on the boundary of inclusions and pores or stainless steel, pressure of hydrogen in air holes can reach a large value (tens of MPA), the stainless steel plate produced in the internal stress caused by hydrogen embrittlement. This will make the stainless steel plate cracking occurred in the cold rolling process of the explosion, the appearance feature is a strip drum bubble, after the breakdown performance of fine black cracks. After rolling, the bubble cracks on the surface of the plate extend and expand, thus reducing the mechanical properties of the products (impact toughness). The method to avoid pickling bubbles is to adjust the concentration of acid solution, control the temperature of pickling solution and the flat state of strip steel. Over pickling If the stainless steel plate to stay too long in the acid solution, the acid solution under the action of the surface of the stainless steel plate is slowly becoming rough pits phenomenon over pickling. The elongation of pickling strip is greatly reduced, and it is easy to break and break in the rolling process, and cause the sticking roll. Even if the strip is rolled, it can not be used as a finished product because its mechanical properties are greatly reduced. The cause of acid pickling is the continuous operation interruption of the unit, which leads to the loss of continuity of the pickling or the long treatment time due to strip breaking. Prevention method must be close to the whole unit operation coordination, to ensure normal production. Acid washing After pickling, the stainless steel strip is called pickling due to its residual surface which does not wash out the oxide scale. In stainless steel strip pickling, the light will face a dark or shaped in the rolling surface; severe iron oxide can be pressed into a black plate. In addition, the extension of the oxide scale is poor, so uneven extension after rolling will make stainless steel appear wave shape or ladle bending defects. Sometimes the iron oxide sheet is firmly attached to the roll surface, which directly results in the increase of rolling waste. Produced under pickling is generally because of the uneven thickness of the oxide scale, thick scale part of the longer the pickling time and at the same time Fe0 is decomposed into a difficult dissolved Fe2O3 (Fe3O4); also some stainless steel wave degree and camber is large, in the pickling process, fire bending part or not soaking in acid pickling by leakage. In actual production, under pickling occurs mainly at the end and end of the strip and on both sides of the strip. Rust The phenomenon of rust on stainless steel plate after pickling is called corrosion. The reason for this defect is that the surface of the stainless steel strip is acid free after pickling, or the stainless steel surface is rusted again after the strip cleaning has not been completely dried. The surface of stainless steel plate corrosion performance in the dark after rolling, the product will lead to corrosion again in place, thereby reducing the surface quality of finished products, even the stainless steel board scrap. The way to avoid corrosion is to strictly carry out pickling and cleaning procedures, and should be stored in a dry place. Inclusion The stainless steel strip is sometimes covered with deeply dotted black spots on the surface after pickling. It is called inclusion. It is because the iron oxide sheet is pressed into the hot rolling. Such defects can not be taken to remove acid washing. When it is cold rolled, black spots expand and extend into black strip, which seriously affects the impact properties of finished stainless steel plate. Scratch The stainless steel strip in a new unit operation in the process of scratching, because foreign body hard surface drive roller, a guide roller, or stainless steel strip shaped and folding edge and guide into the line contact, or strip in unwinding process on the folding scraper, which makes the surface draw new scars. In addition, part of the scar appeared in the process of cooling and coiling after hot rolling. The scratch of stainless steel strip can be pided into upper surface scratch and lower surface scratch. The cold rolled stainless steel plate will form wide and long black strip on the surface of finished stainless steel strip after cold rolling. Stainless steel strip scratch depth exceeds the allowable tolerance of stainless steel strip half, even after rolling can not be eliminated. The way to avoid scratching is to check the rolling parts and guide plates of the unit regularly and maintain the equipment well. Indentation Indentation refers to the indentation of stainless steel strip on the surface of the concave. The reason is in the indentation forming and roll welding without blowing clean welding slag, steel strip is to bottom roller, which pressed on the strip surface marks; hearth roll caused by roll sticking in sliding surface of the strip. The strip surface indentation; hot rolling pressure failure, sudden pressure stop, then lift the pressure under rolling etc.. When the indentation depth exceeds half of the allowable thickness of the strip, the indentation can not be eliminated after cold rolling. Generally speaking, the defects on the surface of stainless steel plate can be avoided and reduced as long as careful operation, strict implementation of the pickling process system and operation procedures, timely inspection and maintenance of the equipment. Source: China Stainless Steel Plate Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The chemical composition of 316 stainless steel in addition of molybdenum, so its corrosion resistance, has greatly improved high temperature strength, high temperature resistant degree is as high as 1200-1300, can be used in relatively harsh environment. ​ In addition, the corrosion resistance of the 316 stainless steel is better than that of the 304 stainless steel. In the pulp and paper production process, if the equipment is made of 316 stainless steel, its corrosion resistance will be better. And 316 stainless steel is enough to withstand the erosion of marine and corrosive industrial environments. 316 stainless steel products can be used in the environment below 871 degrees C, and can be used for a long time in the environment of 927C degrees or more. And the oxidation resistance of 316 stainless steel products is also very good. But in the range of 427 degrees C-857 degrees C, it is best not to continue to use 316 stainless steel, but in the temperature range beyond the continued use of 316 stainless steel material, still can have very good heat resistance. At the same time, it is also noted that the precipitation resistance of 316L stainless steel is stronger than that of 316 stainless steel, and can also be used in the above temperature range. 316 stainless steel plate can not be hardened by heat treatment. In addition, the weldability of the 316 stainless steel is also very good, can be used almost all the standard welding method for welding. When welding, 316Cb, 316L or 309Cb stainless steel filler rod or electrode can be used as solder. However, it is necessary to note that in order to obtain the best corrosion resistance, it is generally necessary to do the post weld annealing treatment of the welded section of 316 stainless steel. However, if the 316L stainless steel is used, there is no need to do the post weld annealing treatment. 316L stainless steel mentioned above, then the next introduction of 316L stainless steel bar. This steel can be used for the production of heat exchanger, dyeing equipment, film materials for external equipment, pipelines, coastal areas of the building or flushing, senior watch chain, case etc.. In addition, it can also be used to produce equipment, chemical dyes, paper making, oxalic acid, fertilizer and other equipment in sea water environment, as well as photography, food industry, coastal area facilities, ropes, CD rods, bolts, nuts. The maximum carbon content of 316L stainless steel is 0.03, which can be used after welding and can not be annealed and need maximum corrosion resistance. Because 316L is also a molybdenum stainless steel, its performance is better than that of 310 and 304 stainless steel. At high temperature, when the concentration of sulfuric acid is less than 15% or higher than 85%, the use of 316L stainless steel is more extensive. In addition, 316L stainless steel also has excellent resistance to chloride erosion, so the performance in the marine environment is also very strong. 316L stainless steel can be used in the middle 1600 degrees off the following environment, continuous use at 700 degrees below, 316L stainless steel has good oxidation resistance, in the range of 800-1575 degrees, then try to avoid continuous use. But the 316L stainless steel can be continuously used outside the temperature range, and the heat resistance is better. The precipitation resistance of 316L stainless steel is better than that of 316 stainless steel, which can be used in the above temperature range. In addition, the 316L stainless steel can be annealed in solid solution at 1010-1150 degrees of temperature and then cooled rapidly. What is needed to know is that the 316L stainless steel can not be hardened after heat treatment. 316L stainless steel has excellent welding properties and can be welded with all standard welding methods. Source: China Stainless Steel Pipe Fitting Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

310S stainless steel angle bar is widely used as engineering structures of various buildings, such as beams, bridges, towers, hoisting and conveying machinery, ships, industrial furnace, reaction tower, container or even warehouse shelves. From the angle of the name can be seen made of 310S stainless steel, 0Cr25Ni20 stainless steel grades for GB, this is also called the 2520 stainless steel is a kind of austenitic chromium nickel stainless steel, has excellent oxidation resistance and corrosion resistance, and also because of the high proportion of chromium and nickel content, 310S stainless steel has excellent creep strength and, good high temperature performance, can continuously work under high temperature. Due to the high nickel and high chromium content in 310S stainless steel, so its resistance to oxidation, corrosion resistance, acid and alkali resistance, high temperature performance is very good, so for 310S stainless steel as raw material, high temperature resistant steel can be made into the electrothermal furnace tube and other products, increasing the carbon content in austenitic stainless steel, can enhance its solid solution strengthening effect and increase strength, chemical composition characteristics of austenitic stainless steel is chrome, nickel based addition of molybdenum and tungsten, niobium and titanium elements, also because of its organization is face centered cubic structure, so the strength and good creep strength at high temperature. 310 stainless steel is now widely used, including petroleum, electronics, chemical, pharmaceutical, textile, food, machinery, construction, nuclear power, aerospace, military and other industries. So what is stainless steel angle bar? An angle bar is a long strip of steel with angles perpendicular to each other. There are two kinds of shape, namely equilateral stainless steel angle bar and scalene stainless steel angle. The two side widths of equilateral stainless steel angles are basically equal, and their specifications are expressed by the width of the edge, the width of the side, the width of the side and the thickness of the edge. In addition, scalene stainless steel angles can be pided into two kinds: unequal thickness, unequal thickness and unequal thickness. The specifications of stainless steel angles can be expressed by the length of the side and the thickness of the edges. Domestic stainless steel angle specifications for 2 – 20 cm, to length number number, the same number of stainless steel angle bar is often 2 – 7 different edge thickness. Import stainless steel angles mark the actual size and edge thickness of both sides, and indicate the relevant standards. The stainless steel angle is usually larger than 12.5cm, and the angle between 12.5cm and 5cm is medium stainless steel angle. The stainless steel angle is smaller than 5cm. The import and export of stainless steel angle bar in China has a certain quantity, generally imported from Japan and Western Europe, and exports mainly to Hong Kong and Macao, Southeast Asia, Latin America and Arabia countries. The export enterprises are mainly steel mills (rolling mills) in Jiangsu, Liaoning, Hebei, Beijing, Shanghai, Tianjin and other provinces and municipalities. Imported stainless steel angle bar varieties are large, small stainless steel angle bar and special shape of stainless steel angle bar, export varieties are medium stainless steel angle, such as 6, 7, etc.. The surface quality of stainless steel angle bar has certain standard stipulation. It is usually required that there is no disadvantage which is unfavorable to application, such as delamination, scab, crack, etc.. The allowable range of the geometric deviation of stainless steel angle bar is also stipulated by the standard, usually including bending, edge width, edge thickness, vertex angle, theoretical weight and so on, and the stainless steel angle shall not have significant torsion. Source: China Angle Bar Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)