Search Results

The most serious problem in the application of stainless steel pipes in soil and water treatment is the corrosion of the medium. In the soil, the corrosivity is usually classified by its resistivity. The experiment shows that if the soil pH is more than 4.5 and has clean drainage and backfilling, 304 and 316 stainless steel will not corrode at more than 2000 ohm / cm in the soil resistivity of 2000. As in other environments, the chloride content associated with pitting and crevice corrosion may also affect the performance of stainless steel in the soil. It is more appropriate to choose 316 stainless steel when it is expected to be a inland or non tidal coastal area with high chloride content. For the coastal areas and other situations that may be applied to greater soil resistance, the use of 2205 duplex or super stainless steel can be considered. If necessary, external protection can be used, such as appropriate protective shell or tape (notice to ensure effective overlap to avoid gap corrosion), and the stainless steel can also be protected by cathodic protection. When stainless steel pipes are used in water supply and wastewater treatment, 304 and 316 stainless steel are generally applicable. They usually do not become thinner during use, so there is no need for corrosion allowance. This allows the manufacture of thin and light stainless steel products that are easy to transport, and also requires very low maintenance during long service cycles. They can withstand more than 30m / s flow rate, and also exhibit good performance under turbulent conditions. Stainless steel pipes do not need to add chemical additives in water to maintain the corrosion resistance of materials, and the leaching rate of metals is also the minimum. If the stainless steel pipe is completely corroded in water, it is most likely to be the form of crevice corrosion. Experiments show that when chloride level is lower than 200ppm and 1000ppm, the probability of crevice corrosion of 304 and 316 stainless steel is very low. However, in design, manufacture and use, it is necessary to avoid cracks as far as possible, which will further reduce the probability of crevice corrosion. In addition, 1000-3600 ppm chloride 2205 duplex stainless steel can also be considered. If conditions are particularly serious, the use of austenitic or super duplex stainless steel containing 6% molybdenum elements should be considered. These stainless steels can be used in seawater applications, where chloride levels can reach up to 26000ppm. The other better method is to use L grade welding, complete penetration welding, and remove surface pollution and heat coloring. After the water pressure test, the moisture should be drained in time. The environmental medium is in a flowing condition, which helps to keep the surface clean. In addition, chlorination is avoided and sodium hypochlorite or ferric chloride is added to the metal wall instead of flowing into a fully mixed flow flow. Areas where chlorine vapor can be collected should be regularly washed with drinking water to prevent concentrated chloride. Source: China Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Selecting the right type of steel for your project is one of the most important decisions. Before deciding inpidual material grades, it is also first necessary to decide which type of steel to use, such as carbon steel or stainless steel. This article will discuss the difference between carbon steel and stainless steel. Corrosion resistance The most obvious difference between carbon steel and stainless steel is the ability to resist corrosion. Stainless steel, as the name implies, will have better corrosion resistance. Both carbon steel and stainless steel contain iron that oxidizes when exposed to the environment, causing rust. However, chromium added in stainless steel makes it more resistant to corrosion than carbon steel. Chromium is more easily attached to oxygen than iron. When chromium adheres to oxygen, a chromium oxide layer is formed, protecting the rest of the material from degradation and corrosion. Carbon steel generally does not have enough chromium to form the chromium oxide layer, which can cause oxygen and iron to combine to form iron oxide or rust. Therefore, if corrosion resistance is a key factor, stainless steel must be selected. Mechanical behavior Due to various different types and grades, it is difficult to clearly explain the difference in mechanical properties between carbon steel and stainless steel. Stainless steel is more ductile than carbon steel because they usually have a higher nickel content. However, there are also very brittle stainless steels, such as martensitic grades. Carbon steels with very low carbon contents may not be able to match the tensile strength of some stainless steels because many stainless steel grades contain alloying elements that increase their strength. However, if there is enough carbon in the carbon steel (usually at least 0.30% by weight), heat treatment is easier than austenitic stainless steel. Surface If this job requires aesthetic appeal, it must consider the appearance of the metal. When appearance is a necessary factor, it is usually also preferable to have special surface treatment of stainless steel. Although both can be sanded and polished to give a bright and shiny appearance, carbon steel needs to be coated or painted after the polishing process. If not, carbon steel will begin to change color and eventually rust. In addition, if the stainless steel is scratched, it will retain its gloss in the scratch area, and if it is carbon steel, it will need to be repainted or it will be corroded. Cost Another important consideration is the cost difference between carbon steel and stainless steel. Although different grades have different costs, stainless steel is usually more expensive than carbon steel. This is mainly due to the addition of various alloying elements in stainless steel, including chromium, nickel, and manganese. These additional elements increase the cost of carbon steel. On the other hand, carbon steel is mainly composed of relatively affordable iron and carbon elements. If the budget is tight on the project, carbon steel may be the best choice. What should we choose in general? The selection of a specific job between carbon steel and stainless steel will involve the trade-offs and careful consideration of all these factors. If the metal is hidden, then no extra money is required on the appearance of stainless steel. However, stainless steel is actually the best choice if it will be hidden but is affected by the corrosive environment. In the end, the choice will depend on the details of the job or project. Source: China Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Steel is one of the most widely used metals in the modern world. It’s cheap, powerful and incredibly versatile. In the world, the annual production volume of steel is about 750 million tons, and steel is the second largest volume production product after cement. Steel is completely recyclable and requires only relatively little energy to produce. Because of the efforts of the steel industry, the current energy consumption and carbon dioxide emissions are only half of the CO2 emissions of the 1960s. This makes steel production very environmentally friendly and sustainable. There are too many steel products, such as railways, oil and gas pipelines, skyscrapers, elevators, subways, bridges, cars, ships, knives and forks, razors and surgical instruments. Before you understand steel, you need to understand the history of iron. Iron is the fourth largest element, accounting for more than 5% of the earth’s crust. The beginning of human iron production began around 2000 BC in the southwest or south central Asia. This marks the beginning of the iron age, and these tools and weapons have widely replaced copper and iron. In this era, wrought iron was produced by blacksmiths who heated the iron and crushed the impurities on the anvil. The iron produced is tough. It was not until the Middle Ages that new types of iron were developed using higher temperatures. This is called cast iron and it is harder than wrought iron but it is also more fragile. It was not until 1870 that a large amount of steel began mass production. Composition of steel Steel is an alloy of iron and carbon. It can contain small amounts of silicon, phosphorus, sulfur, and oxygen. The carbon content of steel is between 0.08-1.5%. This makes it harder than wrought iron but not as brittle as cast iron. Steel also has a unique balance of hardness, flexibility and tensile strength. It is also more durable and more rigid than softer wrought iron. At the same time it is more resistant to impact than the more brittle cast iron. Steel is mainly produced in blast furnaces or electric arc furnaces. The blast furnace mainly uses raw materials (iron ore, limestone and coke) and some scrap steel to make steel. The blast was invented by an Englishman in the mid-1850s and was named Henry Lisbemer. He designed a method for producing steel by blowing molten iron into the air to oxidize the material and separate impurities. The modern blast furnace is a large steel shell shaped like a cylinder and lined with heat-resistant bricks. Iron ore, coke, and limestone enter the furnace from the top, sinking gradually to the bottom, and warming as they descend. In the upper half of the furnace, the gas from the combustion coke releases oxygen from the iron ore. At the bottom of the furnace, limestone begins to react with impurities in the ore and coke forms slag. At the bottom of the furnace, the temperature reached 3000 degrees Fahrenheit. The slag floats on top of the molten steel and is discharged through the slag in the furnace. The molten steel is discharged from the furnace wall through the drainage hole. The electric arc furnace is mainly used for the production of special steels for other metal alloys. Scrap is poured into the EAF from a bridge crane. When the furnace is full, the lid is covered on the top of the furnace. The lid contains electrodes placed in the oven. The electrode carries a powerful current, generating heat, which melts the waste. As the scrap melts, other metals, called iron alloys, are added to the steel to obtain the desired chemical composition. Oxygen is blown into the furnace to purify the steel. Lime and fluorite are added and the impurities are melted to form a slag. The slag floats on top of the molten steel and can be poured out by tilting the furnace. By combining other metals to form steel alloys, a series of special steels can be manufactured in EAF. The most widely used of these is stainless steel, which has added chromium and nickel to give it corrosion resistance. Other special steels manufactured in EAF include steels for engineering, aerospace and armor plating. Source: China Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

When most metals come into contact with certain substances in air or water, chemical changes occur that reduce the integrity of the metal. This process is called corrosion. Among them, materials such as oxygen, sulfur, and salt can cause metal corrosion, and metals with good corrosion resistance are represented by stainless steel plates. When the metal corrodes or deteriorates, it cannot withstand the same load as it did when the corrosion began. So at some point, corrosion can lead to dangerous situations. Metals used in bridges, rails and buildings are subject to corrosion. So monitoring and managing corrosion is very important to avoid the collapse of metal structures. The corrosion rate of a metal is the rate of deterioration of any given metal in a particular environment. The speed or speed depends on the environmental conditions and the type and condition of the metal. The corrosion rate is based on the number of millimeters per year (in thousandths of an inch). In order to calculate the corrosion rate, the following information must be known: weight loss (reduction of metal weight in the reference time period), density (metal density), area (initial total area of the metal sheet), time (length of the reference time period). In order to convert the corrosion rate between annual density and metric tons of equivalent millimeters per year (mm/y), the following formula can be used: 1 mpy = 0.0254mm / y = 25.4 microm / y. Calculate the corrosion rate of metal loss: mm / y = 87.6 × (W / DAT). Where W is the weight loss in milligrams, D is the metal density (g/cm3), A is the sample area (cm2), and T is the metal sample exposure time (hours). The rate of corrosion is important because the rate of corrosion determines the lifetime of the metal structure. This reality determines the choice of metals for different purposes and in different environments. It also determines the maintenance requirements for metal structures. Metal structures in wet environments may require more frequent maintenance than similar structures in the dryer position. Develop a maintenance plan based on the above calculation types. Corrosion engineering is a relatively new profession dedicated to slowing down, reversing and avoiding the effects of corrosion on materials and structures. They are responsible for developing coatings and processes that can be used for metals to improve the corrosion resistance of metals. They are also involved in the development of materials that are not easily corroded. For example, new non-corrosive ceramics can sometimes replace metals. Corrosion engineers can recommend and implement solutions where corrosion can be dangerous or expensive. Source: China Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

ERW pipe (resistance welded pipe) The name ERW is because such stainless steel pipes involve certain types of welding processes such as spot welding and seam welding. Seam welding is usually used when manufacturing round, square and rectangular stainless steel pipes. The stainless steel band is unwound from the coil and trimmed to control the width and adjust the edges for welding. The strip then passes through a series of shaped rolls that cold form the material into a circular (square or rectangular) shape. The edges are joined as butt joints under pressure and then welded by heating the material to a temperature above 2000°F. Wait until the flash weld that has been formed is removed from the outer diameter of the pipe. Once the weld has been tested, it can then pass through a series of sizing rolls to obtain the exact final dimensions, and then the stainless steel pipe is straightened and cut to the required length. The welding state of the product during the manufacturing process (usually called the flash condition) means that when the flash of the weld stays inside the pipe, the ERW pipe is usually not removed or the production process is controlled. DOM Technically, DOM is not a steel pipe but the completion of a stainless steel pipe. It is considered a high quality pipe. The first stage of manufacture is the same as the stage for making an electric resistance welded pipe, but in the finishing stage, the entire flash weld is removed and the pipe is cold drawn on the mandrel. The cold drawing process provides the pipe with better dimensional tolerances, improved surface finish and the highest weld strength achievable. When the DOM actually does have a seam (though barely visible), the DOM is often incorrectly referenced as “seamless.” Seamless steel pipe Seamless steel pipes are manufactured using a method called “extrusion.” In the process, a solid steel rod passes through the center and uses a mold to turn the solid circle into a circular pipe. There are basically two types of seamless steel pipes: Cold drawn seamless (CDS), typically manufactured by SAE 1018, with precise tolerances and good surface finish; Hot Formed Seamless (HFS) is usually manufactured by SAE 1026, with less critical tolerances and scales, not as strong as CDS . The advantages of Cold Drawn Seamless (CDS) are good surface finish, excellent processability, increased dimensional tolerances, and high strength to weight ratio. The advantages of seamless (HFS): cost-effective materials, good processability, a wide range of sizes. Source: China Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The so-called metal quenching is a method of rapidly reducing the metal back to room temperature after heat treatment (e.g., annealing) in order to prevent the significant change in the microstructure of the metal during the cooling process. Quenching results in an increase in the degree of hardening of the steel at the same temperature at which it is fully annealed. How do you perform quenching? Special polymers, forced air convection, fresh water, brine, and oil can all be used for quenching. When the goal is to maximize the hardness of the stainless steel tube, water is an effective medium. However, using water can cause the metal to crack or deform. If extremely high hardness is not required, other media such as mineral oil, whale oil or cottonseed oil can be used during the quenching process. Effect of quenching rate The slower quenching and more thermodynamic changes in the stainless steel tube are opportunities for changing the microstructure. Sometimes this result is preferred, which is why different media are used for quenching. For example, the quenching speed of oil is much lower than that of water. Quenching in a liquid medium requires stirring the liquid around the metal to reduce surface vapors. The steam pocket is quenched by air cooling until it evaporates. Why quench? Typically used to harden stainless steel tubes, water quenching from austenite temperatures will cause carbon trapped inside the austenitic slats. This leads to a martensitic hardening and brittle stage. Austenite refers to an iron alloy having a γ-iron base, and martensite is a rigid steel crystal structure. Quenched steel martensite is very fragile and stressed. Quenched steel is usually subjected to tempering. Normally, metals such as stainless steel pipes will be tempered in the oil, salt, lead bath, or air circulated by the fan in the furnace to restore some ductility (ability to withstand tensile stress) and loss of toughness by conversion to martensite . After the metal is tempered, depending on the situation, in particular whether the metal is susceptible to brittleness after tempering, it is cooled rapidly, slowly or not at all. In addition to martensite and austenite temperatures, the heat treatment of metals involves ferrite, pearlite, cementite, and bainite temperatures. When iron is heated to the high temperature iron form, delta ferrite transformation occurs. According to the Welding Institute in the United Kingdom, it formed “low carbon concentrations from liquid cooled iron-carbon alloys prior to transformation to austenite.” Pearlite is easily produced during the slow cooling of iron alloys. Bainite has two forms: upper and lower bainite. It is produced at a slower cooling rate than martensite formation, but at a faster cooling rate than ferrite and pearlite forms. Quenching prevents the steel from decomposing austenite into ferrite and cementite, with the goal of making the steel martensitic. Source: China Steel Tubes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The base metals usually refer to industrial non-ferrous metals, mainly copper, lead, nickel, zinc, and tin. In addition to copper, all base metals react with hydrochloric acid to form hydrogen. Because of their ease of extraction and large quantities, they are much less expensive than precious metals. The contracts for copper, lead, nickel and zinc are traded on the London Metal Exchange. The base metal is used for various applications from the electric wire (copper) to the battery (lead), as well as to reinforce and harden the metal alloy (nickel), and to coat and protect active metals such as iron (nickel and zinc). The base metals are non-ferrous metals, meaning they do not contain iron. There are multiple exchanges around the world providing these metal contracts, but the International Trade Center is the London Metal Exchange (LME). The LME is the world’s largest producer and consumer exchange. Its contracts are tailor-made for the industry. Market participants can deliver goods within one working day of the year according to their personal hedging requirements. The base metal is the cornerstone of society. Price trends often indicate that the global economy has grown or contracted. Therefore, this commodity market department can have a deep understanding of the economic trends around the world. For decades, due to the country’s economic growth, China has been the most important consumer of the basic metal market. However, the slowdown in China’s economy in 2015 caused many of these metals to decline in the second half of 2015 and early 2016. At the end of 2016, one of the issues in the US presidential election was to rebuild the country’s infrastructure. Donald Trump was elected as the 45th president of the country and has a background in the construction of the real estate industry. The new president promised to become an architect nationwide. The last major US infrastructure project was the Eisenhower administration in the 1950s. It is likely that major repairs to roads, bridges and transport hubs such as airports and train stations will be the main objectives of the Trump administration. In response to the election of the new president and his platform, the rise in the prices of many industrial commodities (including base metals) is impressive. Each base metal has its own characteristics and uses. Copper Copper is an economic chain of goods. The world’s major copper producer is the South American country, Chile. The biggest consumer is China. Copper has many useful qualities. It does not corrode and is an electric superconductor. Buildings, plumbing, refrigeration, air conditioning, cooking utensils, computers, and even some medicines require copper. The main alloy of metal is brass, which can be used to produce musical instruments, building materials, jewelry and some art objects. The copper trading center is the LME, but the COMEX pision of the Chicago Mercantile Exchange (CME) offers a standard futures contract for red metals. The copper ETN product traded on the New York Stock Exchange is the iPath Bloomberg Copper Sub TR ETN- Symbol JJC. Aluminum Aluminum is probably the softest base metal and it has the largest volume of transactions on the LME. Aluminum is the third largest element in the earth’s crust. The world’s leading aluminum producer and consumer is China. Russia and the United States are also major producers. Aluminum is a versatile and lightweight metal. It has countless uses in cars, motorcycles, aircraft parts, license plates, roofs, and sinks. Aluminum is also a key component of window frames, paints, cans, plates, foils, bottle caps, gum and candy wrappers, light bulbs, cell phones and power cords, sports equipment, food additives, and even aspirin and many other consumer and construction products. . LME offers aluminum and aluminum alloy forward contracts. The ETN ETN product listed on the New York Stock Exchange is the iPath Bloomberg Aluminum Sub TR ETN- Symbol JJU. Nickel Nickel is a silvery white and shiny metal with a slight golden luster. It is one of the least mobile metals traded on the LME. The price of nickel may fluctuate very much. One of the main characteristics of nickel is corrosion resistance. Nickel is a metal for iron and brass. Nickel is ferromagnetic, whereas strong magnets require iron and rare earth metals, and medium strength magnets use nickel. Nickel is also an integral part of coin making, glass, rechargeable batteries and some bulletproof safes. The world’s largest producers are China and Russia, but Japan, Canada, Australia and Norway also produce metals. Cuba is a producer of nickel. Due to infrastructure construction projects, China has been the world’s major consumer of nickel ore for decades. Highly fluctuating nickel prices often lead to supply shortages and surpluses between metals, leading to swing prices between the chain and retreat. LME is the center of international nickel trading. The nickel ETN product listed on the New York Stock Exchange is the iPath Bloomberg Nickel Sub TR ETN- Symbol JJN. Lead One of the earliest metals discovered by humans was lead. In Turkey, the statue of lead continued until 6500 BC. Lead is used for many purposes, including pipes, bathtub linings, cosmetics and paint, and even food and wine barrels. The single leading use of lead today is to make batteries, but metals are also used in the construction of some alloys and nuclear reactors. Some art paints and some types of ammunition still contain lead. Lead is an integral part of gasoline production for many years because metal prevents engine knock. However, many countries including the United States today prohibit fuel fuels. The world’s largest lead producers are China, Australia, Peru, the United States, Canada and Mexico. In the refining process, lead concentrates produce a small percentage of gold and silver to produce metal. Lead is a metal that is actively traded on the LME. The ETN product traded on the New York Stock Exchange is the iPath Bloomberg Lead Sub TR ETN-Symbol LD. Zinc Zinc is the third most active metal on LME after aluminum and copper. For centuries before the discovery of zinc as a metal, zinc and zinc compounds were required for brass and zinc compounds, many of which are still found in pharmaceuticals used to relieve wounds and eye pain. The main use of zinc is galvanized steel as anti-corrosion. Zinc is also an important metal in the die-casting industry and is used for rolling zinc in the production of trenches, roofs, pipes, coinage and compounds. China is the world’s leading producer, and Peru, Australia, the United States, Canada, and India also provide the world with a large amount of metal production each year. China is a major consumer of zinc because of the country’s large population and the demand for infrastructure. There is no specific zinc-zinc ETN product in the United States, but the PowerShares DB base metal ETF symbol DBB includes zinc and other base metals traded on the London Metal Exchange. Tin Tin is one of the oldest metals known to man. It is the least mobile or thin traded metal on the LME. Tin’s lack of liquidity has led to huge price fluctuations and periods of shortages and soaring. When it comes to the tin market, it may be either a feast or a famine each year. Plating requires the application of copper, aluminum, steel or other metal tin. Tin has many home applications. We find tin in many drug solutions, capacitors in electrodes, fuses, ammunition, fungicides and pesticides, solders and solder pastes. Even toothpaste requires tin fluoride as a key manufacturing component. China is the world’s largest producer of tin, but Indonesia, Peru, Bolivia and Brazil are also important suppliers of metals in the world. The second largest tin reserve in the world comes from Malaysia; Penang is the center of tin mining and refining operations. Tin is a non-toxic metal. Therefore, in recent decades, it has replaced lead and other toxic elements in the manufacture of many commodities, including electronics and ammunition. China is the world’s leading consumer nation, but the United States, Japan, and Russia are both important importers of metals. The Tin ETN product listed on the New York Stock Exchange is the iPath Bloomberg Tin Sub TR ETN- Symbol JJT. Source: China Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Desalination plants are known to be very corrosive because of the high temperatures in the environment. Austenitic stainless steels of the previous 300 series are often the preferred materials for desalination plants. In cases where higher corrosion resistance is required, typical material solutions have exceeded the higher alloyed austenite grades of the 300 series stainless steels such as austenitic 6Mo grade (UNS NO 8367)ii. Recently, in many cases, 2205 stainless steel and other duplex stainless steels have become more optimized materials. There are many reasons why 2205 stainless steel and other duplex stainless steel have gained popularity in the seawater desalination industry. First, duplex stainless steels have good corrosion resistance and in many cases can save costs compared to comparable austenitic stainless steels. For example, Duplex 2205 has similar pitting and crevice corrosion properties as 904L (UNS No 8904) but can be obtained at a lower cost because its chemical composition includes a lower percentage of expensive metal ii. In addition, duplex stainless steel has high strength. Specifically, 2205 is almost twice as strong as austenitic stainless steel. Therefore, less material weight is usually needed, which can further save costs. Duplex stainless steels have been successfully implemented in many applications in desalination plants, including evaporators, as well as SWRO BWRO high pressure piping, and numerous parts and product water processing connections II. Here are some specific examples. Solid Duplex and Duplex Evaporators: The breakthrough in dilute industrial duplexing occurred in 2003 when the 2205 was selected for installation at the MSF plant in Melittah, Libya, Italy, built by Italy’s REGGIANE. The 2205 can use thinner plates to build evaporators than conventional evaporator materials such as austenitic 316L (UNS S31603), requiring less material and less welding. Other advantages include easier handling and lessening the overall impact of the environment on me. Both the Melittah factory in Libya and the Skikda factory in Algeria (built in 2004 and 2005) have successfully demonstrated the ability of Duplex 2205 to meet the needs of these environments. With the successful application of the 2205 evaporator, Outokumpu proposed the DualDuplexx evaporator concept. The DualDuplex evaporator uses two different types of duplex stainless steel in the evaporator structure to maximize cost and material savings. 2205 For parts exposed to the most severe conditions and thin duplex, LDX21011 (UNS 32101) and Duplex 2304 (UNS 32304) are used for parts exposed to less harsh conditions [iii]. The high strength of the lean duplex makes it possible to increase the gauge of these components by up to 50% compared to austenitic stainless steels, although the limits in design specifications limit the actual savings by about 35% to 40%. DualDuplexx evaporators have been successfully implemented in several desalination plants, including the Taweelah B expansion in Abu Dhabi, the Jebel Ali L plant in Dubai and the Ras Abu Fontas desalination plant in Qatar. SWRO high pressure pipe: The experience of the large number of seawater reverse osmosis (SWRO) plants already in use shows that if the wrong stainless steel is used in the high-pressure piping required for this environment, there is a high risk of corrosion. The 316L (UNS S31600) and 317L (UNS 31603) grades do not have sufficient corrosion resistance to withstand this environment. Therefore, highly alloyed austenitic steels, such as 254 SMO (UNS S31254), are considered to be more or less mandatory years v. However, recently, the super-duplex brand such as the SAF 2507 (UNS S32750) has made great progress in this area. The SAF 2507 is an ideal solution, with almost the same resistance as pitting and crevice corrosion of 254 SMO, twice the strength, and much lower cost than v. Singapore’s Singspring desalination plant provides about 10% of fresh freshwater demand and is a good example of SAF 2507s’ successful implementation. SAF 2507 is used for the high pressure pipeline iv fed to the incoming seawater through initial seawater reverse osmosis (SWRO). Singspring has been running since 2005 and SAF 2507 continues to perform well. Source: China Duplex Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Nickel is a silvery white metal with magnetic properties and good plasticity. With good corrosion resistance, nickel is nearly silver-white, hard and malleable, and has a ferromagnetic metallic element that is highly polished and resistant to corrosion. After dissolved in nitric acid, it is green. Mainly used for alloys (such as nickel steel and nickel silver) and as a catalyst (such as Raney nickel, especially as a catalyst for hydrogenation) In 1751, Alex Fredrik Cronstedt, who works in Stockholm (Swedish capital), studied a new metal called nickel arsenite (NiAs) from Los Alpin, Helsinki, Sweden. He thought it contained copper, but what he extracted was a new metal that he announced and named nickel (nickel) in 1754. Many chemists think of it as an alloy of cobalt, arsenic, iron and copper—these elements appear as trace amounts of contaminants. It wasn’t until 1775 that pure nickel was made by Torbern Bergman, confirming that it was an element. Nickel ore comes from the earth’s crust and is mined through open pit mines and deep wells. The smelting and refining process separates metal from mined ore. About 1 million tons of nickel are produced each year from mines around the world. The largest production comes from China and Russia, which accounts for about 50% of global production. Other important nickel producers include Indonesia, the Philippines, Japan, Canada, Australia, Cuba and Norway. The supply of nickel in China consists of two components, one is the supply of new nickel concentrate, which accounts for 72.9% of the total supply of nickel, and the other is from reclaimed nickel, which accounts for 27.1%. With the development of the economy and the development of the steel industry, nickel The demand is constantly increasing. Because nickel has good corrosion resistance, it is often used in electroplating. It is mainly used for alloys (formulations) (such as nickel steel and nickel silver) and as a catalyst (such as Raney Nickel, especially as a catalyst for hydrogenation). It can be used to make currency, etc. It can be plated on other metals to prevent rust. Mainly used to make stainless steel and other corrosion-resistant alloys, such as nickel steel, nickel-chromium steel and various non-ferrous metal alloys, nickel-containing high copper-nickel alloy, it is not easy to corrosion. Also for hydrogenation catalysts and for ceramic products, specialty chemical vessels, electronic circuits, glass green and nickel compounds, etc. Due to the needs of infrastructure construction, China is the major consumer of all base metals. While the nickel industry in China continues to develop, there are also some problems, such as the low taste of nickel ore, the small percentage of open mining, the recoverable reserves only account for 10% of the total reserves, and the mining and smelting technologies are relatively backward; Weak acid or weak alkali medium flotation process is generally adopted, and the ore processing capacity is 4.3 million tons/year. China’s nickel smelting is generally selected by the pyrometallurgical process except for several large-scale enterprises. Nickel sulphide anode membrane electrolysis and sulfuric acid are mainly used for refining nickel. Selective leaching – electrowinning process, and the world’s advanced technology there is a certain gap, so the cost of mining and smelting in China remains high. Source: China Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

For many years, the Duplex 2205 has been widely used in the oil and gas industry. In 2007, a 2205 pipe was implemented for the natural gas pipeline in Amsterdam in the Burhansi district of Oman. Duplex stainless steel 2205 was selected due to its high strength and corrosion resistance. Duplex Stainless Steel 2205 Case Study: For many years, the Duplex 2205 has been widely used in the oil and gas industry. In 2007, a duplex stainless steel pipe 2205 was implemented for the natural gas pipeline in Amsterdam in the Burhansi district of Oman. Duplex stainless steel 2205 was selected due to its high strength and corrosion resistance. Duplex stainless steel 2205 generally performs well in environments that include carbon dioxide in a wet gas stream. In addition, it was selected due to the availability of materials at the time. The pipeline in the Burhani district is 36 kilometers long and passes through the desert and the Wadis. The duplex stainless steel 2205 pipe has 8 inch and 14 inch outside diameter dimensions. They are designed to emit a mixture of moisture and condensed water at a rate of 15 to 4 million cubic meters per day. Super and super duplex case studies: The super- and super-duplex phases are becoming increasingly popular in the oil and gas industry, and are particularly suitable for important parts that are resistant to design stresses. Many levels have been designed for this purpose, including SAF2906 (UNS S32906), 3207HD (UNS 33207) and Super Duplex 2507 (UNS32750). Super Duplex Stainless Steel 2507: Canadian Oil Company recently implemented a pipeline of super duplex stainless steel 2507, along with 2205 duplex stainless steel code plus twoo, developed in their oil field off the coast of Newfoundland, Canada to combat seawater corrosion and existing pipelines IV. Super Duplex 2507 is a high alloy super duplex steel for extremely corrosive conditions. Primarily used for applications where high stress is exposed in chloride-containing environments such as seawater, it contains a large amount of chromium, molybdenum, and nickel. It has high tensile strength, high impact strength, low thermal expansion, high electrical conductivity, excellent resistance to stress corrosion cracking, and high resistance to pitting corrosion. Precision Biphase Case Study: Compared with Duplex 2205, super and super duplex stainless steels are being used in areas that require advanced performance. When duplex 2205 is too high for the application, precision duplexing offers the opportunity to reduce costs. In addition, poor duplexes have good weldability, which is very advantageous in the construction of flexible pipes and umbilicus. The following are some case studies of the thin duplex LDX 2101 (UNS S32101) and AL20033 (UNS S32003): LDX2101: Technip uses LDX 2101 as a deepwater project in Angola for total Dalia. In addition, Rath Gibson also used the LDX2101 to build a galvanized umbilical. The precision duplex stainless steel 2101, which has stronger corrosion resistance than 304, has twice the yield strength, which can save significant cost and weight. AL20033: In 2007, Precision Duplex AL2003 was successfully applied for the first time to unlimited flexible pipes. It was used by Murphy Oil as an oil field outside Sabah, Malaysia, known as Kikeh Field. Unbonded flexible pipes are often used around the world to transport liquids from oil and gas fields under the ocean. These pipes typically consist of a polymer and carbon steel material that is extruded and wrapped around an inner stainless steel carcass. Duplex 2205 and austenitic steels have been used for flexible pipe bodies for many years. Flexible pipes absolutely require good corrosion performance. In addition, for deep oil fields, high strength is another important component. As the tube stress level increases, a larger cross-sectional area is required to further increase the weight. The Kikeh site at 1400 meters is actually too deep to even consider the use of 316L pipes. Various tests were conducted to evaluate the resistance to collapse, corrosion resistance, strength, and corrosion resistance in accordance with the expected environment and fatigue resistance. Based on these tests, it was determined that AL2003 met or exceeded 316L in all qualification tests and was considered an improved replacement for the 316L carcass in an unbounded flexible pipe. AL2003 also tested Duplex 2205. Although Duplex 2205 performs better than AL2003 in many areas, the result is that such a level is considered to be a satisfactory Kikeh environment. The AL2003 offers a cost advantage over the Duplex 2205, which is considered ideal for the high pressure needs of marine piping systems that transport moderately sweet oils and gases. Source: China Duplex Stainless Steel Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Early development of duplex stainless steel: Duplex stainless steel, which combines many beneficial properties of ferritic and austenitic stainless steels, was originally developed in the early 1930s. The initial duplex stainless steel provides good performance characteristics but has limitations under welding conditions. The metallurgical process at the time was not suitable for producing grades with the correct austenite-ferrite balance. In addition, the carbon content of these early duplex stainless steels was relatively high because there was no effective decarburization process technology at the time. Therefore, the production of these materials is often the main production limited to some specific applications. Modern duplex stainless steel development: In the late 1960s and early 1970s, several factors led to the development of duplex stainless steel. First, the introduction of vacuum and argon deoxygenation (VOD and AOD) processes opened the door to the production of modern biphasic grades. These developments make it possible to achieve a good balance of low carbon content with high chromium content, high nickel content, and ferrite and austenite. This can produce materials with very good properties. Alloy content provides good resistance to local and uniform corrosion. The two-phase microstructure contributes to the high resistance to chloride stress corrosion cracking under many conditions and high strength. Modern duplex stainless steel also has good weldability. These modern duplex stainless steels appeared in the same period as the offshore industry increased its activities. The industry needs a stainless steel that can handle aggressive environments. Although austenitic steels can also withstand these aggressive environments, the lack of nickel at the time led to higher prices. All these factors combine to encourage the offshore oil industry to adopt duplex stainless steel. Duplex stainless steel 2205: Duplex stainless steel 2205 (UNS S31803 / 32205) is the first commercially developed “second generation” duplex steel. It was developed in the mid-1970s and was introduced by the Krupp Steel producer in Germany. Today is still the most common duplex stainless steel that is currently considered the key material for duplex stainless steels. Duplex stainless steel 2205 provides corrosion resistance in many environments superior to Type 304 (UNS S30400), 316 (UNS S31600) and 317 (UNS S31700) austenitic steels. In addition, the yield strength is about twice that of austenitic stainless steel. Interestingly, the composition range initially set to 2205 (S31803) was later determined to be too wide. According to the original composition specification, biphasic 2205 may form a harmful intermetallic phase at high temperatures. In order to achieve the best corrosion resistance and avoid these intermetallic phases, the content of chromium, molybdenum and nickel needs to be maintained within more than half of S31803. This modified 2205 is called S32205 and is a typical example of the commercial production of Duplex 2205 iv today. Precision duplex stainless steel: Although duplex stainless steel 2205 continues to gain momentum in various industries over time, in some cases extraordinary corrosion resistance is already higher than required. This has led to the development of many streamlined duplex stages such as LDX 2101 (S32101), ATI 2003 (UNS 32003) and Duplex 2304 (UNS S32304). These new duplex stainless steels not only contain less than 2205 alloying elements, but also can be used for alternative 304 or even 316 grade applications. For example, duplex alloys are used in many construction applications due to high strength, good corrosion resistance, and lower overall cost, commonly used stainless steel grade 316. Super duplex: In addition, since the 1980s, the petroleum industry has been one of the main driving forces for the development of even higher-alloy dual-phase materials, known as super duplex and super duplex. These higher alloy biphasic grades are designed to handle extreme environments such as higher corrosive conditions and higher pressures encountered at larger depths in oil and gas fields [V]. Super duplex grades have an equivalent pitting resistance (corrosion resistance, also known as PRE or PREN), higher than 40. The number of PREs at the super duplex level is 48 or higher [v]. Currently, the current product categories include the super-duplex SAF 2507 SD (UNS S32750) and super-duplex SAF 3207 HD (UNS S33207) and SAF 2707 HD (UNS S32707). Although the current duplex stainless steel market accounts for a very small part of the total stainless steel, duplex stainless steel is a developing industry and its prospects continue to grow. From the International Stainless Steel Forum ISSF, studies have shown that duplex output soared from 6,000 tons a month, increased to 10,000 tons in 2004 to 2005, and up to 22,000 tons in 2008. Duplex steel continues to gain popularity as various industries begin to consider the entire life cycle cost. In addition to the potential immediate material cost savings, the use of duplex stainless steel can also lead to longer life cycles and lower maintenance costs in many cases. Source: China Duplex Stainless Steel Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

In the past few decades, the severity of corrosion in the oil and gas industry has increased year by year. Because the offshore oil industry continues to push oil exploration deeper, it leads to higher pressure conditions and harsher environments. In addition, advanced technologies have increased the total capacity of domestic reservoirs, thereby increasing the life expectancy of subterranean wells and the concentration of corrosive agents in these wells. In order to adapt to these difficult environments and to safely prevent the high cost of component failure, it has become crucial to ensure that the right alloys are selected for use in the oil and gas industry. This creates an excellent application opportunity for duplex stainless steel 2205 and other duplex stainless steels. At the end of the 1970s, when it was selected as a natural gas pipeline, duplex stainless steel was first introduced into the oil and gas industry. At the time, this option provided an important commercial breakthrough for Duplex 2205 (UNS S32305 / S31803). It not only helped the smooth application of duplex stainless steel 2205 to the oil and gas industry, but also incorporated many other industries. Until now, duplex stainless steel 2205, streamlined duplex, super duplex, and duplex have played an increasingly important role in both the onshore and offshore oil and gas industries. Oil and gas production: Oil and gas production processes vary according to the environment, but high-level steps remain relatively stable over time. Oil is found in reservoirs under the seabed or deep wells and extracted using small diameter high pressure pipelines with mixed gas and water. Once the oil mixture reaches the surface, it passes through the wellhead and is then typically fed through a larger diameter, lower pressure lateral conduit until it reaches the separator vessel. In the separator vessel, the gas rises to the top, the water flows to the bottom, and the oil separates out in the middle. The gas is usually re-injected into the reservoir, refined and sold or expanded. Water is injected into the reservoir. Then the oil is sent to the pipeline to the refinery. The advantages of duplex 2205 and other duplex stainless steels: Duplex stainless steel has two distinct advantages that make this material attractive to the oil and gas industry. First, it has excellent resistance to various corrosive media commonly found in both onshore and offshore environments. These mainly include CO2, H2S gases, chlorides, low pH conditions and water. The high resistance to chloride-induced stress corrosion cracking of dual-phase steels is particularly important. Second, its high intensity is very beneficial in dealing with the high levels of high pressure encountered. Duplex stainless steel can also provide some material cost advantages compared to alternatives, but up-front costs are usually not a major driver, especially for seabed extracts. The huge cost of failure in the oil field makes the best material for the job to be selected in the early stages. Therefore, it is important that all cost calculations include life-long maintenance and potential cost risks due to failures so that the costs can be really assessed when selecting materials. Duplex stainless steel application: Duplex stainless steel 2205 and other biphasic grades are increasingly preferred materials for process piping systems, separators, scrubbers, pumps, manifolds, X-mas tree assemblies, flow lines, and piping for transport of corrosive oils and gases. . In the case of resistance to design stress, super and super biphasic grades are preferred. The biphasic grade has become the standard configuration for flexible tubes and umbilicals. Not only does duplex stainless steel prevent corrosion, but they have the ability to support their weight in deep water. Source: China Duplex Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)