Since the development of stainless steel over hundred years ago, it has become world’s most used and popular material. Since stainless steel has the notable corrosion resistance that helps in increasing features with chromium content. The resistance can be shown in reducing acids as well as against pitting attacks such as in chloride solutions. It requires low maintenance, and is familiar to luster thus making it an ideal and best material for SS pipes.
This versatile material is indispensible in wide industries. This may contain number of application especially for SS pipes that benefit user with positive properties.
Iron-containing alloys made from more than two chemical elements are known as stainless steel. It is widely been used in comprehensive range of applications. Stainless steel alloy is basically steel alloy with iron, nickel, and chromium percentage contents in abundance.
The stainless steel has been in presence for centuries, since it is vulnerable toward corrosion and works better in tough condition. The stainless steel gets recognized late in year 1800’s with a combination of iron-chromium with offered rust resistance. Since, then it is mold into stainless steel pipes so that it gets used for number of industrial applications.
In 1912, a researcher of brown-firth laboratory founded a martensitic SS alloy finally. The new material got labeled as Staybrite. The stainless steel alloy comprises of iron alloy with minimum amount of chromium up to 10.5%. You can see tremendous variety of alloys in the market, the only thing they differ is in chemical composition. The alloying elements are titanium, nickel, carbon, copper, nitrogen that can boost formability, strength, and other SS properties.
The stainless steel pipe is available in different product type such as welded pipes and seamless pipes. The composition may vary and this makes it possible to use it in respective industries. Generic industrial company use stainless steel pipe for regular use.
Let us see different stainless steel pipe types used in different scenarios-
A pipe that has absence of weld joints or seams are known as seamless pipe. It can withstand intense or extreme temperature and pressure. All the tanks go to the metal. The seamless pipe gets utilized in comprehensive range of application like gas and oil application. They are also utilized in mechanical as well engineering industries. This is what makes it versatile before they reach the client; they got inspected with precision level that makes sure its high quality assurance.
Almost in every industry welded pipes got used because of its flexibility. However, they cost better when it comes to serve high corrosion resistance thus opposing the pressure. The welded pipes are lightweight because of the kind of material used. They are cost-effective as compared to other piping methods when it comes to pay your money.
Another important part overall piping system is required is pipe flanges. The pipe flanges are available in variety like threaded, semis, lap joints, and blinds. They are sturdy material and durable which ensure offering of high quality product with utmost level of reliability.
Nearly all stainless steel pipes available in the market are iron-based alloys which comprised of minimum chromium content of 10.5%. A self-healing or protective oxide layer gets formed on the alloy when it contains chromium. The stainless steel pipe got its corrosion resistance property through formation of oxide layer. The self healing characteristics of oxide layer imply that intact corrosion resistance can be achieved regardless of fabrication means.
It has the capability to self heal and offer high corrosion resistance even if the pipe surface experience any damage or cut. On the other hand, the protective layer formed by normal carbon by coating or painting such as galvanizing. Underlying steel as well as corrosion gets exposed on surface modifications.
The working of corrosion resistance may differ with different stainless steel pipe grades in various environments. The stainless steel pipe have two main characteristics in common- they posses resistance and contain chromium which makes it immune to attacks. The stainless steel pipe is unaffected by aggressive alkalis, acids, and other chemicals.
Pipe grades that contain high nickel, molybdenum and chromium show more resistance to corrosion.
Cryogenic Resistance (low temperature)-
The cryogenic resistance in low temperature gets measured by toughness or ductility at sub zero level temperature. The austenitic stainless steel tensile strength is substantially higher at cryogenic temperature, compared to ambient temperature. They also possess the capability to maintain excellent toughness, in harsh environment.
At sub zero temperature, the precipitation hardening, martensitic, and ferritic steel pipe are not to be used. At low temperature, the grade toughness significantly drops. It is found in some cases, the cryogenic resistance drops down closer to atmospheric temperature.
One of the biggest advantage of work hardening of grades of stainless steel pipes is the it increases and enhances the metal strength significantly and helps in achieving cold working. The combination of annealing and cold working stages are easy to employ so as to give off fabricated components appropriate strength.
High strength can be retained at peak or elevated temperature. The stainless steel pipe grades that contain huge chromium or silicon, nitrogen is responsible for hot strength. High hot strength can be offered for the grades of chromium ferritic grades.
The stainless steel pipe with high chromium content assists in resisting scaling at peak or elevated temperatures.
Strength and Formability
The stainless steel pipe of different grade offer different ranges of strengths. Compared to mild strength the strength remains constant somewhat in soft conditions. The softer austenitic steel contains exceptional elongation and ductility. Hence, it can be cold worked so as to give a finished product with extensive series of semi-fabrication. In order to reach the final condition, the toughness and strength gets combined in effective manner.
Good range of ductility and strength get offered by the ferritic stainless steel pipes. Subsequent heat treatment gives off hardness and high strength, in case of martenisitic steel pipes.
The % elongation is responsible for ductility while tensile test. The austenitic stainless steel elongation is high. High work hardening and high ductility rates enable austenitic stainless steel so as to form and work in sever processes like deep drawing.
In comparison to mild steel, the stainless steel has higher amount of tensile strength. The duplex stainless steel generally has higher strength compared to austenitic steel. In the martensitic grade the highest level of tensile strength can be seen as well as in precipitation hardening grades. These grade types possess double strength compared to other grades.
Magnetic response is generally attraction of stainless steel. Austenitic grades are purely non magnetic and it can be induced in few austenitic grades through cold working. Grades like 316 and 310 are generally non-magnetic with cold working. All other stainless steel grades are magnetic.
High as well as Low Temperature Service
The stainless steel can retain strength in high proportion when it got heated. It shows discolor when heated at very high temperature. Consequently, the stainless steel pipes get used at industries at extreme temperatures. The strength of pipe can decrease with the reduction in various factors. At high temperature slow but steady type of elongation can be seen with resistant to insidious.
It is durable when comes in contact to combustion products at range of temperature near to 1100 degree c. The temperature reaches -196 degree C in some processes this may result in loss of ductility as well as toughness. Specific austenitic stainless alloys get used with Ni alloy base for making it ideal.
Stress corrosion cracking or SSC–
Stress corrosion cracking or SSC is basically sudden cracking due to failure of component or deformation. This gets occurred when following conditions are encountered-
- Any of the part gets stressed due to residual stress
- The pipe don’t have sufficient resistant
- The stainless steel pipes are manufactured in such a way that it shows high level of stress corrosion resistance.
Heat and fire resistance
Due to the combination of nickel and chromium alloy grade has the capacity to resist scaling as well as retain strength at very high temperature.
The stainless steel pipes are easy to clean and because of this client usually choose it. It can be used in abattoirs, Kitchen, hospital, and industry such as food processing plants.
The stainless steel pipes are bright and can be maintained because of attractive and modern appearance.
Weight-to strength advantage
A significant strengthening can be resulted due to work hardening property from cold working. Over conventional grades, the duplex grades have reduced material thickness.
Ease of fabrication
Using modern techniques, the stainless steel pipes can be easily formed, machined, welded, fabricated and cut.
The austenitic microstructure of stainless steel offers high toughness at elevated temperature. That’s why it can be used in cryogenic applications.
Long term value
If you consider the total or overall life cycle of stainless steel you will find that least expensive material gets used. Long term benefits can be availed by the stainless steel pipes.
Now you have known why stainless steel gets used, let us see in what kind of industries it gets utilized-
Oil and Gas
It is evident that in gas and oil industries technology and tools plays vital role. Over the past years, the requirement of corrosion resistant piping system has been explored deeply. Super duplex and duplex stainless steel pipes get used immensely in oil and gas industries. It shows incredible corrosion resistance in harsh and tough conditions. If there exists any damage the pipe system would be unusable and burst easily for deeper depths. That is why it is recommended that sturdy pipes get used in gas and oil industry so as to work well in industry.
Gathering energy from nuclei of an atom is not at all an easy task. The kind of nuclear reactor we make use of offer steam through water which is passed to spin turbines near the coast so as to get energy for cooling requirements. Then water is the pumped to reactors through the stainless steel pipes. These pipes fulfill the need or requirement of corrosive nature in seawater. In order to defend to corrosion stainless steel pipe must qualify so that it can be served to nuclear power industry.
It is old saying that industry and standards goes hand in hand. The production as well as testing gets may vary because of the variation in different organization standard for wide application ranges. The buyer first need to understand the basics of different industrial specification for their projects, have a glance from below paragraph.
ASTM stands for American Society for testing and materials. The ASTM international offers service standards and industrial material over wide range of sectors present in industries. This particular organization has served 12000+ standards presently that got used in industries all over the globe.
Nearly 100+ standards pertain stainless steel pipes, and fittings. ASTM covers nearly all variety of pipes unlike other standard organizations.
Fox example- full range of pipe gets stocked as American pipe products. For high temperature services, seamless carbon pipes get used with appropriate standards. The determination of chemical composition and specific manufacturing process related to material defines the ASTM standards.
The permitted quantities are magnesium, nickel, carbon etc by “Grade”.
For example- Grade A and B helps in identification of carbon steel pipe. Furthermore, ASTM grades can be arranged according to flanges, pipes, fittings and nuts.
A106 -these specifications gets used for high temperature services
A335 – for high temperature services seamless ferritic steel pipe
A333 -for low temperature usage welded and seamless alloy steel pipes gets used
A312 – for general corrosive service and high temperature service, cold worked welded, straight seam welded, and seamless pipes are used
ASTM standards are instrumental in testing, evaluating mechanical, installation requirement, design, and specifying pipes.
The production of welded pipes from continuous coil or plate involves rolling of plate or coil in circular section with assistance of roller or bending machine in continues process. in large size manufacturing can be done using filler material. Welded pipes are cheaper unlike seamless pipe that are more expensive. Basically there are various welded methods such as-
EFW– electric fusion welding
ERW– electric resistance welding
HFW– high frequency welding
SAW– submerged arc welding (spiral seam or long seam)
In this section you will learn and understand about pipe manufacturing process like HFW, EFW, ERW, and SAW. From continues coil as well as strips, welded pipes are produced. In order to produce manufactured pipe the coil or plates are first rolled in shape of circular using plate blending machine.
The circular section then gets forwarded to second section. In the second section, welding set up helps in welding of pipe. The pipe can be easily welded without or with filler material through appropriate welding process. The welded pipes are in general much cheaper as compared to seamless pipes but are weak because of welded joints. The welded pipes are produced in large sizes with no upper restriction. Long radius elbow and bends can be formed through manufacturing of welded pipes.
Now, you have known basic formation of pipe through rolling machine. This similar process can be used so as to produce thick SAW pipes.
SAW Welded Pipe Produced Process
External filler metal such as wire electrodes gets utilized in connection of formed plates. Single longitudinal seam is known be incorporated in saw pipes based on the pipe size. However, for non-critical process or low pressure services saw pipes are utilized.
Welding is done in single seam SAW pipes, through submerging in arc welded process. For outside, a solid filler wire gets used continuously. Then the pipe gets welded from outside.
In double seam SAW pipes, through tack weld two halves gets connected which is known as Fit-up. Havening of two seams back to back is responsible for double seam pipe. Seam is welded from outside and inside of the pipe. Multiple pass welding gets executed through high thickness pipe.
De-coiler is formed from steel plate in spiral SAW pipe in spiral loop. This loop is welded from outside and inside of the pipe. Wide range of diameter, using the different manufacturing process is produced.
For low pressure process, the spiral SAW pipes get used. For medium or high pressure service, straight saw pipes gets used. Spiral pipes get utilized in comparison to straight pipes.
Heat treatment is then carried out after welding, on the entire body of pipe. The seam welded pipes are then subjected to many of the non-destructive testing like UT and RT testing so as to make use that welded material is soundness.
Once it is completed they are hydro tested so as to make use that it has the ability to show leak proof sealing under pressure, and strength. The pipes are then checked dimensionally and visually through ac competent inspection engineer as the last stage of testing.
AS per standard need, mark is posted before sending to esteemed clients.
ERW/ EFW welded pipe manufacturing-
The ERW/EFW welded pipes are less thickness pipes that get formed by constant rolling methods. In this sort of method, metal strip is feed from strips into roller series that got assembled in line. Strip gets formed gradually in circular section. At pope rolling end assembly, pipe is welded continuously through welding machine.
The HFW, EFW/ERW makes use of welding methods, with no addition of filler material. However, along with filler material EFW welding methods are used.
ERW Pipe Production Process
In the ERW welding manufacturing, copper developed two electrodes are utilized so as to apply current and pressure. The electrodes are usually of disc shapes that rotate when the material passes through them. The electrodes are then allowed to so as t o stay firmly in contact to make continuous welding successful.
Low voltage and high current generally AC power through welding transformer is used to connect pipes that has extreme level of resistance. It is then heated so as to bring it at melting point through current. The semi-molten surfaces of pipes are brought together by a force so as to develop a fusion bond and uniform welded structure is the result of it.
HFW Pipe Manufacturing
In order to develop welded joints, a high frequency current gets used in HFW welding. However, external high energy arc gets utilized so as to develop welded joints in EFW welding process. Excess accumulation of welded material from inside and outside of the pipe is then trimmed or removed using a trimming tool.
Localized heat treatment over the weld seam pipe gets used so as to reduce negative welding effect. Once it clears off the ultrasonic test. IN order to restore microstructure of pipe, induction heating method gets utilized. This particular heat treatment is termed as post annealing.
In the next stage, the HFW pipe are allowed to pass through the dimensional inspection, visual, hydro testing, and the test certified with inspection engineer for packaging.
The manufacturing of electric resistance welding is followed by rolling metal across its length. By metal extruding, seamless pipe are produced to desired length. The ERW is joints welded along its cross section whereas seamless pipes are joint through its length.
In seamless pipes the whole of the manufacturing is done through solid round billet and this is no welding. The seamless pipes got finished to wall thickness and dimensional specification in various sizes. For high pressure application like oil and gas transportation, industries and refineries, these pipes are used.
Electric resistance weld pipes are in general welded longitudinal, which is manufactured through coil or strip. It is used for medium or low pressure application like water or oil transportation. You can get common sizes for seamless or ERW pipes in variety of lengths. Surface finishes are made available in coated formats and bare formats to esteemed client as per the need or requirement.
The stainless steel pipes are offered in type based shapes such as square, round and rectangular. Each and every shape of stainless steel is discussed below in brief-
Stainless Steel Round Pipes
The round pipes manufactured by us are generally austenitic class round pipes that is considered weldable through common methods such as resistance and fusion techniques. When it is cold formed production of visible undulated surface by the grain size is appeared known as “orange peel”.
The stainless steel pipes offered has modified version because of the combination of aluminium and titanium level so as to make use serving at optimal temperature. Because of austenitic microstructure, the round pipes are capable of offering impact strength at room as well as at cryogenic temperature.
Stainless steel seamless round pipes also show resistance toward formic, phosphoric, sulphuric, non oxidizing media and acetic acids. It also possesses resistance toward stress corrosion cracking, weld heat, knife line, pitting corrosion- that is considered affected zone attack. Exceptional corrosion resistance, in addition, makes round pipe fabrication possible.
For production of casing in gas and oil production, it gets supplied with higher strength properties. Some of the known features are consistent operation, ruggedly constructed, easy to maintain, affordable prices and superior in performance.
The round pipes have size range as ½”-24” NB. It has grades as TP-304/L/H, TP-321/H, and many more. The standards are ASTM A249-A358-A269-A778-A409-A789-A790. The tolerance length for commercial is 6000mm and for fix length it is 1200mm-12000mm. The finish could be solution annealed, brushed, seamless, welded, and pickled up and mirror polished.
We also offer round pipes in various designs, shapes, and different sizes as per customer specifications and demands at reasonable prices. Some of the known types are stainless steel round seamless round pipes, steel EFW round pipes, stainless steel round ERW welded pipes and stainless steel ERW seamless round pipes.
Stainless Steel Square Pipes
We offer distinguished stainless steel square pipes that works well in multi purpose plants such as in upset conditions frequently. For aggressive environments like chloride containing media, warm chlorinated seawater as well as acidic media, these pipes are particularly used.
Our production worker contains years of experience in effective manufacturing of these square pipes so as to provide low cost and high quality pipe with best service assurance. The temperature that it can withstand is 600 degree F and the carbon content is responsible for becoming critical.
The stainless steel square pipes get attached by gases in approximately 700 degree F as well as in molten sulphur attacks at 500 degree F. It offers similar corrosion resistance as that of nickel but with higher temperature and working pressure at low cost because of superior ability to get machined.
The SS Square Seamless Pipes that we offer is notable because of its toughness that gets maintained over a substantial range of temperatures and pressures. The square pipes are resistant to corrosion as well as to acids. Some alloys of pipes can withstand a blaze in pure oxygen. It is both cold-worked as well as hot-worked. The SS Square Welded Pipes doesn’t demand thermal treatment in order to develop the best combination of ductility of strength as well as to minimize distortion throughout subsequent machining. We offer these pipes in diverse sizes, shapes as well as in designs as per clients’ demand and need at reasonable price.
Similar to stainless steel round pipes it also has features as superior performance, considerable price, consistent operation, easy to handle, rugged construction and high grade quality.
The square pipes have size range as ½”-24” NB. The standards are ASTM A249 -A409-A789- A358-A269-A778-A790. The tolerance length for commercial is 6000mm +/-30mm and for fix length it is 1200mm-12000mm and +/-0.5mm. The finish could be brushed, seamless, welded, annealed, and pickled up and mirror polished. It has grades as TP-304/L/H, TP-321/H, and many more.
Stainless steel rectangular pipes
The SS Rectangular Pipes that are offered by us show higher resistant towards; many corrosive medias that too with good electrical, thermal as well as magneto-strictive properties. The corrosion rate is low in pure unaerated acids for all application at atmospheric temperatures. In hot as well as concentrated solutions, the rate is usually high for rational service life.
Steel Rectangular Pipes must be utilized in nitric acid media only in solutions ranging with 0.5 % concentration at room pressure and temperature. These rectangular pipes are also utilized in sea water corrosion-resistant assemblies, cooling circuits, ammunition, and condenser tubes. Stainless Steel Rectangular Seamless Pipes that gets offered by us is readily get bigger into tube sheet that is necessary for the effortlessness of manufacture of tube shell and heat exchangers.
The rectangular pipes can be both hot and cold formed through stretch or drop hammer, hydropress, power brake methods. Stainless Steel Rectangular Welded Pipes is utilized for piping, seawater systems, heat exchangers and condensers in marine hardware. Sometimes it is utilized for the propellers, hulls of premium tugboats, crankshafts, fishing boats and working boats. We offer the rectangular pipes in unlike sizes, and shapes designs in accordance to clients’ specifications at practical price.
The test performed on pipe shapes are Destructive test, non destructive test, positive material test, micro and macro test, chemical test/ spectro analysis, intergranular corrosion test, flaring test, hydrostatic test. Special pipe testing are charpy test, Mechanical test, hardness test, tensile test, ultrasonic test, radiographic test, flattening test, pitting corrosion test and visual inspection.
The documents that are offered along with product are Commercial invoice, packing list like net and gross weight, quantity and marks, specification guide, fumigation certificates, and number. Other documents are NABL test report, MTC report as per EN 10204 3.1 or 3.2 and guarantee letter.
The stainless steel pipes are packed in wooden boxes, crates, cartons, and cases, individual pole wrap with stretch film, Spiral wound paper tubes, cores on its pallets.
Stainless steel pipes are utilized in number of applications based on the grade and purpose. The application pipes are made through the mixture of alloys that got selected as per the industry type or purpose it need to serve. The stainless steel can be utilized for instance, in aircraft hydraulic lifts, or other industry.
Many of the renowned factories such a production line or mills make use of stainless steel pipes for easy working of equipments. In order to resist high temperature and pressure strength of the stainless steel must be chosen according to it.
Some of the unique properties it offers are sustainable as well as long lasting alloy steel, less brittle, high rust resistance, low & high temperature resistance and less magnetic permeability, and higher aesthetic appeal.
Stainless steel is basically steel alloys with low percentage of chromium. The addition of chromium improves corrosion properties related to steel. The maintenance of steel pipes is really easy with oxidation resistance.
These metals never ever spoil other metals that come in contact and can be used in numerous application types. Pipe manufactory can be used in application where tough and harsh working is required.
Based on the pipe’s end usage, the types of pipes can be classified. It is classified in various grade types of pipes. Today, in the market numerous number of steel types are made available when it coems to gain desirable properties with added particulates.
The stainless steel pipe is best suited for applications where corrosion resistance required arises.
Martensitic or ferritic steel types contains chromium so that it can be used in heat treatment as well as annealing applications
The stainless steel pipe of austenitic type comprises of nickel and chromium content which provides more resistance for usage in harsh conditions.
Given below are basic stainless steel pipe types
Pressure pipes- Pipes that are produced through the combination of nickel and solid chromium are known as pressure pipes. High acidic features at high temperature are offered with seamless welded electric fusion and large diameter pipes. The pipes that get used to carry fluid at high level of pressures are known as pressure pipes.
It helps in transferring of fluid via input and output. It works well with forge fluids as well as tanks or pipe from mods. It has the capability to transfer multiple amount of fluid on similar pipe. It can filter fluid type on its output as well as input. It has smart distribution between outputs.
The another type of Stainless steel that is related to high sanitation applications such as sensitive application is known as sanitary pipes. In industry this pipe type has highest priority for effective flow of fluid. The pipe possesses highest corrosion resistance and it doesn’t tarnish by providing maintenance ease. As per the application, various tolerance levels gets decided. Sanitary pipes with ASTMA270 grades get utilized.
Sanitary pipe gets produced using effective methods so as to make it hygienic fitting types. They are used due to its easy cleaning and it can be easily dismantled. Manual cleaning or CIP process can be executed. The place where bacteria harbor or form is limited by this pipe. The pipe has corrosion resistance. All sanitary pipes get measured in OD tube. You can measure the diameter of sanitary pipe if you hold it on your hand.
Most of the sanitary stainless steel pipes may be either 316L or 304 stainless steel pipes. The sanitary pipe fittings don’t have any tight radii, threads, or pockets. The sanitary fitting provides sanitary clamp or buttweld clamp.
In mechanical pipe application, hallow parts, bearing parts and cylinder parts are used typically. The mechanical can be controlled easily to wide variety of sectional shapes like rectangular, square, and other shapes in adding up to regular or traditional shapes. The commonly used grade types in mechanical applications are A554 and ASTMA 511. Mechanical steel pipe gets utilized in machined as well as formed parts such as transportation, household equipment, aircraft, farm machinery, automotive machinery, and industrial applications.
The stainless steel pipes are available in wide range of sizes and grades. The formation of mechanical pipe can be achieved through austenitic stainless steel or other steel. The typical mechanical pipe has size in range of 1.5-9 inch.
Excellent machinability– Most of the mechanical pipe grades has excellent machinability with consistent properties so as to increase cutting speed, set up times and reduce tool wear.
Cutting service– The mechanical pipe can be offered by top manufacturer and producer in random lengths or any of the cut to fixed length that has a range from 2.5-6.5 m. .
The polished stainless steel pipes get used in house facility precisely based on the specifications. Acclaimed enterprise engage in offering of comprehensive array of stainless steel polished pipes. The polished pipes help in reducing wear and tear on operating parts. It also helps in reduction of adhesion and contamination of surfaces of various equipments. The electropolished surface can be used in many applications.
The polished pipes offered helps in promoting cleaning as well as help in reduction of down time association. The polished pipes are offered internationally and nationally along with high quality material. The top manufacturer offer pipes in customized thickness and sizes as per client demand or requirement at marketing prices.
Stainless steel polished pipes inherit no additional coating, corrosion resistant, and finishing needed. For decorative and architectural application, the polished pipes play an important and crucial part. Consistent and uniform surface finishing of polished pipes can be created.
Some of the leading features of polished pipes are durability, smooth, fine fishing, top quality handlebars, corrosion resistance, and uniform surface and consistent surface, dimensional accuracy. Manufacturing of polished pipes can be soft or cold rolled, descaled, and polished rolls.
All the stainless steel Type based pipes such as mechanical pipe, pressure pipe, polished pipe and sanitary pipes gets utilized in number of applications based on application purpose.
Because of the ability of stainless steel to resist rusting against harmful chemicals and tough environment, it has been remarkably been used in industries. It shows incredible resistance to alloying environment and components when exposed to it. Various sorts of stainless steel are served in industry for variety of purposes. Out of all those stainless steel products, stainless steel 304/304L pipes are the most preferred.
Each and every type of SS is graded in series. The series classifies different sort of stainless steel ranging from 200- 600. All the grade pipes are available in different properties from families such as Ferritic, austenitic, martensitic and duplex hardening stainless. High resistance and high strength toward corrosion is well shown by all stainless steel grades.
The given below info shows difference between two types available in market- 304 and 304L.
304 Type Stainless Steel
304 Type is one of the most widely utilized austenitic or non-magnetic stainless steel. It is commonly termed as “18/8” SS due to its compositions that may include 18% chromium and 8% nickel. The type 304 SS has welding properties and good forming properties like strength and strong corrosion resistance.
This sort of stainless steel shows good drawability. It is made available in various sizes and shapes with regard to other grade types. It can be exercised with no annealing. Type 304 is commonly used in food industry. It is ideal for milk processing, wine making and brewing. It is also used for pipelines for yeast pans, storage tanks, fermentation vats.
Type 304 stainless steel is found in tabletops, sinks, refrigerators, utensils, cooking appliance and stoves. It has the ability to withstand corrosion which got cased by various chemicals such as milk, meat and fruits. It can also be used for chemical architecture, heat exchangers, and chemical containers.
Type 304 got used in water filtration systems and mining systems.
304L Type Stainless Steel
Type 304L SS products are extra low carbon content products in comparison to 304 steel alloys. In 304L lower carbon content, harmful carbide precipitation and deleterious get minimized during the welding process. Therefore, the 304L products are known as “welded products” that works well in corrosive environment and it is also capable of eliminating annealing need or requirement.
The grade has lower mechanical properties compared to standard 304 grades. Like 304 stainless steel, it also gets used in wine making and beer-brewing. It has purpose beyond food industries. It is also ideal for metal parts such as bolts and nuts when exposed to brine water.
Magnetic response test- the product is kept under permanent magnet so as to see whether it got work well in cold working or not. E.g. – rolling, bending, and forming.
Nitric acid reaction- the nitric acid reaction is executed when the product is kept in strong nitric acid at room temperature. It is to see whether it can work in harmful or corrosive environment or not.
Molybdenum spot test- the steel is clean first using abrasive paper and a drop of standard solution is poured on it. Presence of Mo confirms darkening of the drop. It is to see whether it avoid skin and eye exposure or not.
Stainless steel grade 310 pipes are basically medium carbon stainless steel that can be used for higher temperature applications such as heat treatment equipment and furnace parts. In continuous service, it can withstand temperature of 1150 degree C and in intermittent service, the bearing temperature is 1035 degree C. 310S is also known as low carbon version compared to grade 310.
Stainless Steel 310/310S Applications
The typical applications of grade 310/310S are- it is used in kilns, fluidized bed combustors, tube hangers and steam boilers, lead pots, and refractory anchor bolts. It is also used for food processing equipment, muffles, cryogenic structures, and retorst.
Grade 310/310s Properties
These grades comprises of 20% nickel, 25% chromium. This is what makes it highly resistant to corrosion and oxidation. Grade 310S are basically low carbon version that is less flat to embrittlement. It also shows sensitization in services. The highest and medium chromium and nickel content respectively make the stainless steel capable for reducing sulphuric atmosphere that contain H2S.
They are used widely in moderate carburizing atmospheres like in petrochemical environments. Heat resisting alloys are used in more severe atmospheres. Grade 310 is not at all recommended for quenching that use frequent liquids from thermal shocks. This grade type is often exercised in cryogenic applications because of low magnetic permeability and toughness.
In common with austenitic SS, these grades are not at all hardened through heat treatment. It can’t be hardened through cold work and is practiced rarely.
Chemical Compositions for Grade 310/310S
Grade 310 as well as grade 310S stainless steel has different chemical compositions which is summarized in the next paragraphs.
The grade 310 and 310 S has carbon, silicon, sulphur, manganese, phosphorus, nickel, and chromium. For each element that chemical composition is different.
Mechanical Properties of Grade 310/310S
The mechanical properties of 310/310S grades are summarized as- grade 0.2% proof stress, tensile strength, elongation and hardness with 205, 520, 40, and 225 respectively.
Physical Properties of Grade 310/310S
The physical properties of 310/310S stainless steel are summarized as- at room temperature density, electrical resistivity, shear modulus, poisson’s ration, electrical conductivity, and melting point respectively. Other physical properties that make it incredible product are relative magnetic permeability, coefficient of expansion, and thermal conductivity.
Fabrication of 310/310S SS
Grade 310/310S fabrication involves forging in temperature gap of 975-1175 degree C. At 1050 degree C heavy work can be carried out easily then a light finish got applied to the bottom. After forging, basically annealing is recommended so as to relieve stresses from forging process.
Machinability of grades
Grade 310/310S pipes can be machineable and the only problem is work hardening. It remove work hardening layer through slow speed as well as sharp tools. It can be lubricated. Rigid tools, heavy tools and powerful machining can be used.
Welding of grades
The grade 310/310S can be welded with electrodes as well as filler metals. Some of the welding process these grades readily suit are GTAW, SAW, GMAW. There isn’t any requirement for post heat and preheat for corrosion service.
Grade 316/316L is basically a standard moly-bearing grade type that has got second position in importance to 304 grade types. Better overall resistance to corrosion is provided by molybdenum, particularly crevice corrosion and pitting resistance is also served in chloride environments.
Grade 316L is generally known as low carbon content of 316. It is immune to sensitization. That is why it is extensively utilized in heavy gauge weldable components.
There isn’t any price difference between 316 and 316L stainless steels pipes. Excellent toughness is offered by austenitic structure.
As Compared to nickel-chromium stainless steels, the 316L offer highest stress to rupture, creep and tensile strength at peak temperature.
The grade 310/310S has chemical composition with elements such as nitrogen, Molybdenum, silicon, Phosphorous, chromium, and manganese as well as carbon.
The mechanical properties are appropriate elongation, yield strength, hardness Rockwell B, and tensile strength. Physical properties are appropriate density, specific heat, thermal conductivity, electrical resistivity, and elastic modulus.
Various atmospheric environmental ranges are offered in which the product works well. It is subjected to crevice corrosion and pitting corrosion in hot chloride environment. The product works well at 60 degree C for stress corrosion cracking. It shows resistant toward potable water at 1000mg/L under ambient temperature.
The 316 is regarded as “marine grade SS” however it is not at all resistant toward hot sea water. In marine environment, this product does inherit surface corrosion. This particular product comes in associated rough surface and crevice finish.
In intermittent service, the product has good oxidation resistance. At 925 degree C it works well in continuous service. The grade 316 works well at 425-860 degree C and it is not recommended to use it in aqueous corrosion. Toward carbide precipitation, the grade 316L shows more resistance. It has higher strength at peak temperature and it shows pressure containing applications temperature exceeding 500 degree C.
It is capable of working in solution treatment. It can be heated at 1010-1120 degree C and it can be cooled rapidly.
All standards grades can be welded using resistance and standard fusion methods. It can be welded with as well as without filler metals. The grade 316 has a requirement of post welding for corrosion resistance however no post welding annealing is required.
It isn’t weldable through oxyacetylene welding methods.
The 316L SS tends to work awesomely if machining is done. For constant feed rates and low speeds 316L is recommended.
316 is much easier to machining because of low carbon content.
Cold and hot working
It can be hot worked through hot working techniques. The temperature range 1150-1260 degree C is suitable for hot working temperatures. Some of the common working operations on 316L are drawing, stamping, shearing. Post work annealing is easily carried out via removing internal stress.
Hardening as well as work hardening-
- Toward heat treatment, 316L is not at all hardened. It can be only be hardened by cold working so as to increase strength.
- The grade 316/316L is well used in architectural applications, marine applications and pharmaceuticals.
The stainless steel is in general known as super alloy steels. The product consists around 4 to 30% content of chromium. They can be easily classified into Ferritic, martensitic, austenitic steels as per the crystalline structure.
Grade 317 is tougher compared to other stainless steel. Chip breaker usage is recommended for machinability of grade. Constant feeds reduce the hardenability that is why low speed gets used.
The grade grade 317 steel pipes are all weldable through resistance and fusion methods. For this particular alloy, oxyacetylene is not all used. For obtaining good results, 317L or AWS E/ER317 filler metal gets used.
The grade 317 can be hot worked through common procedures used for hot working. At 1149-1260 degree C or 2100-2300 degree F, it can be heated but below 927 degree C is shouldn’t be heated.
Cold working is successfully done through heading, shearing, drawing and stamping. Reduction of stress can be achieved through annealing.
At 1850-2050 F annealing is done by cooling. Grade 317 doesn’t retort to heat treatment. However, it can be cold worked.
Some of the applications in which grade 317 gets used are textiles, chemical equipment, and pulping paper.
Grade stainless steel 317L pipes are basically low carbon content pipes compared to grade 317 pipes. The grade has corrosion resistance and high strength and it can even produce strong welding because of low carbon content.
It has chemical composition in definite proportion with elements like silicon, sulfur, manganese, chromium, iron, molybdenum, carbon, and phosphorous.
Mechanical properties that contribute immensely to pipes and are poisson” ratio, tensile strength, yield strength, elongation at break and hardness.
317L manufacturing process require constant feeds and low speeds so as to reduce work harden tendency. The steel is generally tougher compared to grade 304. It is available with long stringy chip. It makes use of chip breaker. Welding is recommended through resistance and conventional fusion. Oxyacetylene welding must be avoided.
Another thing that could be performed is conventional hot working. The product is heat at temperature range of 1149-1260 degree C or 2100-2300 degree F. It is recommended not to heat it below 927 degree C or 1700 degree.
With grade 317L drawing, heading, stamping, and shearing is possible and elimination of internal stresses is done through post work annealing. At 1010-1121 degree C or 1850-2050 degree F, annealing is performed which is carried out then through rapid cooling.
However, the grade 317L shows no response toward heat treatment.
Some of the applications of grade 317 SS are nuclear fueled power stations, petrochemical process equipment, and condensers in fossil.
The elements in the grade 317/317L are Fe, Cr, Mo, P, S, C and Ni. The grade 317L has mechanical properties, which displays detail regarding tensile strength posson’ ratio; hardness, modulus of elasticity, yield strength and elongation at break.
The 317L exhibit excellent corrosion resistance for a comprehensive range of chemicals, such as acidic chloride environments. It also shows resistant to sulfuric concentration at 120 degree f. This grade is readily used for welding, due to low carbon metal and higher molybdenum content. It has properties as good weldability and good formability.
The grade 321 is basically an austenitic stabilized 18/8 steel by titanium or niobium addition. They are not at sensitive toward intergranular corrosion upon heating that’s why they got used within range of 425-850 degree C. Grade 321 is the foremost choice of applications that require temperature range near to 900 degree C, with combined resistant to scaling, high strength, as well as phase stability to aqueous corrosion.
One of the modified versions of 321 is termed as 321H that has higher carbon content so as to offer improved and enhanced temperature strength. The limitation that 321 hold is that the titanium content can’t transport higher temperature arc. This is what makes it not recommended for welding.
Like other grades, 321 also offer welding and excellent forming characteristics that are readily roll or brake formed. It also exhibit excellent welding characteristics. For this grade type, post weld annealing procedure is not required. They show excellent toughness at cryogenic temperature.
For decorative applications, grade 321 steel pipes is not at all recommended because it is not polished well.
The typical composition of grade 321 is S, Cr, Si, Mn, C, N and Ni. The mechanical properties of grade 321 contain appropriate amount of tensile strength, hardness, elongation, and yield strength. The physical properties may contain specified specific heat, electrical resistivity, mean coefficient of expansion, and density.
Corrosion resistance– This grade is superior if welded in annealed condition, but is not recommended for post weld annealed process. At 425-900 degree C, industrial application can be performed. At 60 degree C, the grade can be subjected to crevice corrosion and pitting corrosion as well as stress corrosion cracking in chloride environment.
Heat resistance- In intermittent service, it offers good oxidation resistance at 900 degree C whereas in continuous service the temperature is 925 degree C. it can even perform well at 425-900 degree C in aqueous corrosive conditions. Higher hot strength can be achieved through 321H which is particularly utilized for higher temperature in structural applications.
The grade 321H stainless steel is purposeful austenitic steel it is stabilized toward carbide precipitation. It is especially designed so as to work in temperature range of 427-816 degree C or 800-1500 degree F. this grade is purely non magnetic and it can easily be hardened through cold working. In the alloy composition titanium is added so as to suppress boundary chromium precipitation as well as to reduce suspectibility toward intergranular corrosion.
The steel grade 321h pipe is well used in various applications such as jet engine parts, chemical processing equipment, and aircraft exhaust manifolds and stacks.
Both 321/321H is advantageous for extreme temperature services due to good mechanical properties. The grades also offers stress rupture and higher creep properties. It can be considered for intergranular corrosion and sensitization exposures.
Cold forming, hot forming as well as machining is possible for both grade types. Operations such as turning at high speed, cutting at high speed, and drilling at high speed are possible. Various tests get conducted on the pipes so that high quality product is offered to esteemed clients.
The SS 347 pipes are dimensionally accurate, durable, and sturdy and are available in impressively corrosion resistant feature. With international as well as national standards, these stainless steel 347 pipes got produced. The grade 347 also offers reliable sensitization resistance toward higher temperature.
The 347 stainless steel pipes are in general austenitic stainless steel grades with columbium and tantalum addition that contribute in giving outstanding intergranular resistance toward corrosion. The maximum percentage of chemical composition in grade 347 are – phosphorous (0.045), molybdenum (0.50), carbon (0.08), manganese (2), chromium (19), sulphur (0.03), and copper (0.50).
The 347 stainless steel pipes have forming capability and superior welding. The grade 347 gets utilized frequently in petroleum refineries, pressure vessels, heat exchangers, welded fabrications, and power generation. Typically 347 stainless pipes are utilized in development joints, head gaskets, rocket machine parts. The addition of columbium offers the grade 347 pipes good power so that it can combat weathering.
The grade pipes are offered in square, round, rectangular, and oval shapes. It is also offered in customized option to esteemed or global customers. The schedule of it may be SCH20,SCH60, SCH80, SCH160, SCH40, SCH30. The form may be fabricated, welded, LSAW or seamless pipes. The length may be double random, single random and cut length. The end of pipes may be treaded, beveled, or plain end.
The grade 347H ss pipes is basically common stainless steel type that resembles properties with 321,304, 316, and it can be used well at elevated temperatures. Just like the stainless steel 347H also exhibit welding qualities, and excellent forming due to addition of tantalum and columbium for exceptional intergranular corrosion.
The alloy 347H also exhibit higher carbon variants that enable it to offer creep resistance at temperature range of 537 degree C for higher strength. The stainless steel grade 347H has improved corrosion resistance for strong oxidizing environments. The grade is basically non magnetic typically in annealed conditions and it can be hardened through cold working.
The stainless steel 347/347h is basically popular because they are utilized in aircraft engine components, petroleum refineries, heat exchangers, and high heat applications.
The stainless steel 347 and 347H pipes are available in both welded and seamless forms both in NB and OD sizes.
The outside diameter could be 6.00 mm OD – 250 mm OD, it can be customized upto 12’ NB. It has thickness ranging from 0.3 mm to 50 mm. Or else, it can be SCH XXS, SCH 160, SCH 80, SCH 10, SCH XS. The grade may have types as welded, CDW, fabricated, and seamless. The forms may be rectangular, square, round, “U” shape, or coiled pipes.
The length could be required length, double random and single random. It has end as beveled, treaded, and plain end. The end protection could be done into plastic caps. It has outside finish as No.8, and no. 1. The delivery condition could be cold drawn, annealed as well pickled or polished.
The inspection test report of grade 347/347H includes visual inspection reports, chemical reports, mill test certification, third party inspection and destructive test reports.
The full identification of pipes can be summarized as per the nominal pipe size, grade, schedule, specification, grade, heat number, method of manufacturer, and manufacturer’s name.
The stainless steel pipes grade 904L is in general non-stabilized austenitic steel that contain low carbon content. The high alloy steel when added to copper helps in enhancing strong acids resistance like sulphuric acids. The stainless steel of grade 904L possess crevice corrosion, and stress corrosion cracking. It is generally non-magnetic that offers toughness, excellent formability, and weldability.
The grade 904L generally posses, incredible amount of expensive ingredients like nickel and molybdenum. Presently, most of the applications employ grade 904L ss pipes that replace duplex stainless steel.
The grade 904L SS exhibit excellent resistance toward chloride attack and warm seawater. Stress corrosion cracking is offered because of presence of higher composition of nickel. Moreover, copper addition to grades helps in developing resistance toward reducing agents and sulphuric acid in both mild and aggressive conditions.
The grade 904L has intermediate corrosion resistance between standard austenitic grades and super austenitic grades along with 6% content of moly. This particular grade is less resistant toward acids such as nitric acids. Followed by cold working, this steel grades have to be solution treated so as to achieve maximum stress corrosion under critical environment.
The grade 904L offers high oxidation resistance. However, the stability of structure gets collapsed at temperature above 400 degree C.
The grade is heat treated at temperature of 1090-1175 degree C which is then followed by rapid cooling. For hardening of grades, the grade is thermally treated.
The grade 904L is welded using conventional or traditional methods. This grade type not at all requires post weld as well as pre weld heat treatments. It can be presented toward hot cracking under constrained weldments. The grade can be used according to AS 1554.6.
The stainless steel 904L grade has higher purity of steel with sulphur in low content. Using standard methods, the grade can be machined. It can be bends under cold condition although, subsequent annealing, can’t be demanded in most of the cases. Fabrication is performed or carried out in severe stress corrosion.
Features of 904L pipes– the 904L steel pipes exhibit crevice corrosion and pitting corrosion resistance. The 904L steel pipes also have stress corrosion cracking. It has maximum service temperature at 450 degree C. Toward intergranular corrosion, good resistance can be offered as well. The type 904L pipe has weldability and formability. This grade type exhibit good oxidation resistance and the structure provide stability at high temperature above 400 degree C.
Its applications– the grade 904L has various application usages such as in house processing capabilities as well as industrial application. It is very well utilized in gas scrubbing plants, oil refinery components, paper and pulp processing industries.
It is offered in various specifications, dimension, standards, pipe sizes, types, form, and end. Like other pipes, the types are LSAW pipes, Welded, fabricated, and EFW pipes. The end is treaded plain or beveled end. Form are coiled pipes, rectangular pipes, round pipes, square pipes, and hydraulic pipes. It is tested and then packed with utmost care.
Top manufacturer and supplier offer variety of stainless steel pipes both in welded and seamless pipe that includes cold drawn seamless and hot finished seamless pipe. The most offered stainless steel pipes are 304, 316, 309, 321, 317, 304L, 321H, and 347. These pipes are delivered worldwide with price quotation.
The pipes price is decided on basis of length, standard, specifications, type, form, and finish. The price can be in rupee, or in any other currency such as dollar. Global or international clients can cross check the price through helpline or contact number. Contact reliable and trustworthy manufacturer for further detailing.
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What makes stainless steel real stainless?
Stainless steel contains around 10.5% chromium. This chromium then reacts with oxygen present in the air or surrounding to form a layer known as chrome-oxide layer which is invisible however strong so as to protect further oxygen. Higher chromium levels as well as alloy element addition like molybdenum and nickel improves surface layer. This is what improves corrosion resistance.
What causes difference between 18/10 and 18/8 stainless steel?
The very first element present in stainless steel is chromium i.e. 18 percentage chromium. The second element present in stainless steel in abundance is nickel i.e. around 8% nickels So, as the name given to 18/8 stainless steel. When the composition is higher the material possesses higher corrosion resistance. Both 18/10 and 18/8 contain nickel and belongs to “300 series”. The series 400 doesn’t exhibit corrosion resistance properties and is magnetic however 300 series is non magnetic.
Is it possible that stainless steel will get rust?
Stainless steel never rust, the regular steel gets red oxide over the surface of the pipe. The red rust is due to iron particle which gets contaminated over the stainless steel surface. The instructor can try solution of 2% hydrofluoric acid and 10% nitric acid at room temperature. Now the area must be washed.
Is there any difference between 316 and 304 stainless steel?
The 304 stainless steel has 18% chromium as well as 8% nickel. The 316 stainless steel contains 10% nickel, 16% chromium, and 2% molybdenum. In order to assist with corrosion molybdenum is added to it.
How magnetic stainless steel is?
Several or various stainless steel types are offered. The series belonging to 300 that contain nickel is purely non magnetic. Whereas the 400 series are magnetic as it contain no nickel but chromium.
What is “passivation”?
When chromium content exceeds around 10 ½% a layer of chrome oxide gets formed that protects oxygen diffusion on surface and a “passive” result can be obtained. It shows oxidation to resistance or corrosion. When 10% nitric acid and 2% hydrofluoric acid is dipped the passive oxide layer is developed.
Is it possible to weld stainless steel?
Yes. Various stainless steel available from us can be welded. The welding procedure may be different compared to other carbon metal. The stainless could be welded using electrode or filler rod.
Is it possible to “hardened” stainless steel?
Yes. Stainless steel with series 300 is easily “hardened” however it can’t be ‘work hardening”. That is why the material gets cold worked trough lighter gauges, and cold rolling down or “drawing” via die or altering operations Annealing of stainless steel help sin removing effect of work hardening. The 400 series contain two major stainless steel types. One is acknowledged as “Ferritic that has 430, 409, and 439 that can be hardened by conduct of heat. The other series is known as “martensitic” that has 403, 420, and 410 as basic grades.
What “L” designation implies in a grade?
The letter L after a particular grade such as 904L implies that that carbon content in the material is restricted to a max of 0.03%. The normal level has 0.08% max whereas it is 0.15% max. When welding is performed lower carbon level is used this assist in protecting chromium from getting depleted.
What is meant by stainless steel recycle content?
Yes it is 100% possible recycling of stainless steel. The stainless steel can be easily re-melted so as to form new stainless steel. The recycled stainless steel can be used to form new stainless steel between 65-80%.
What is meant by “annealed conditions”?
Usually, in conditions such as “annealed” conditions the stainless steel is sold. The 300 stainless steel series is not at all hardened through heat treatment however is can only be hardened via cold working. Heat treatment eliminates cold work that will automatically restore soft conditions.
What is meant by “CRES” term?
The CRES stands for Corrosion resistant steel and is designate to stainless steel.
Is it possible to utilize stainless steel at very high and low temperature?
Yes it is possible to utilize stainless steel at low as well as high temperature. It can also be used at temperature 1800 degree F to liquid nitrogen temperature.
What is meant by AISI specification for SS?
AISI stands for American iron and steel institute which is originated for 300 and 400 number system series. It is published with chemical analysis, physical properties, and mechanical property listing for individual grade. The most specifications are in ASTM or American society for testing material.
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