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Technical Information for Type 410 Stainless Steel Alloy UNS Number SAE Number  410  S41000  51410 GENERAL PROPERTIESType 410 Stainless Steel is a hardenable, straight chromium stainless steel which combines superior wear resistance of high carbon alloys with the excellent corrosion resistance of chromium stainless steels. Oil quenching these alloys from temperatures between 1800°F to 1950°F (982 to 1066° C) produces the highest strength and/or wear resistance as well as corrosion resistance. This alloy is used when strength, hardness, and/or wear resistance must be combined with corrosion resistance. RESISTANCE TO CORROSIONType 410 Stainless Steel exhibits good corrosion resistance to atmospheric corrosion, potable water, and to mildly corrosive chemical environments because of its ability to form a tightly adherent oxide film which protects their surfaces from further attack. Exposure to chlorides in everyday type activities is generally satisfactory when proper cleaning is performed after exposure to use. For maximum corrosion resistance to chemical environments, it is essential that the stainless steel surface be free of all heat tint or oxide formed during forging, annealing, or heat treating. Al surfaces must be ground or polished to remove any traces of oxide and surface decarburization. The parts should then immersed in a warm solution of 10-20% nitric acid to remove any residual iron. A thorough water rinse should follow the nitric acid treatment. PHYSICAL PROPERTIES Melting Point Density Specific Gravity Modulus of Elasticity in Tension  2723° F 1495° C  .276 lb/in³ 7.65 g/cm³  7.65  29 X 106 psi 200 Gpa MECHANICAL PROPERTIES Alloy Temper Tensile Strength Minimum  (psi) Yield Strength Minimum 0.2% offset  (psi) % Elongation in 2″ Minimum NotesType 410 Stainless SteelAnnealed65,00030,00020 %– All values specified are approximate minimums unless otherwise specified. Values are derived from the applicable AMS and ASTM specifications. CHEMICAL PROPERTIES Alloy C Mn P S Si Cr Ni Mo Cu N Other410.151.00.040.0301.0011.50-13.50.75.50.50.08Al=.05, Sn=.05 All values are maximum values unless otherwise specified. Values are derived from applicable AMS and ASTM specifications. WELDING N/A HEAT TREATMENT To anneal this alloy, heat to 1500-1550° F (815-842° C) and hold for one hour per inch of thickness and furnace cool to room temperature. Such annealing should produce a Brinell hardness of 126-192 HB. A hardening heat treatment is necessary to bring out the maximum hardness and wear resistance. Since these materials absorb heat very slowly, they should be heated gradually and allowed to remain at temperature long enough to ensure uniform temperature in thick sections. For maximum strength, hardness, and corrosion resistance, slowly heat the alloy to 1800° F (982° C) and quench to room temperature in oil. For thin sections, air cooling can be substituted for the oil quench. If retained austenite is known to be present after the austenitizing and quench to room temperature, additional hardening response may be achieved by sub-zero cooling to about –100° F (-73° C). The as-quenched structure of fresh martensite is quite brittle and should be stress-relieved or tempered at approximately 400 to 500° F (204 to 260° C) to restore some ductility. During tempering between approximately 300° F (149° C) and 600° F (316° C), a relaxation of the martensite structure occurs whereby the volumetric stresses associated with the formation of martensite upon quenching are relieved. As a result, type 410 stainless steel still exhibits its high hardness and wear resistance properties but some ductility is introduced at the loss of a few pints of hardness. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Type 410 (UNS S41000) is a martensitic stainless steel that can achieve a variety of properties through heat treatment. This alloy has good corrosion resistance and high strength and hardness. Type 410 stainless steel is reserved for applications that require some corrosion resistance and high mechanical properties. Type 410 Stainless Steel Specifications: ASTM A240 for annealed condition ASTM A666 for tempered material*Composition per ASTM A240Carbon.080 -.150Manganese1.00 MaxPhosphorus.040 MaxSulfur.030 MaxSilicon1.00 MaxChromium11.50 -13.50Nickel.75 MaxNitrogen Molybdenum Mechanical Properties (Annealed, Per ASTM A240)UTS65,000 ksi MinElongation % in 2″20.00 MinRockwell Hardness  RB96.00 Max ​* Tempered mechanical properties are available upon request. Type 410 Stainless Steel Applications: Hardware Stainless Steel Flanges Stainless Steel Tubes Stainless Steel Nuts Stainless Steel Bolts Stainless Steel Screws Kitchenware Knives and other kitchen utensils Magnetic Properties: Type 410 stainless steel is magnetic in all conditions. Forming: Type 410 stainless steel has a moderate ability to be formed and drawn into other shapes. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

410 stainless steel is a basic martensitic grade of stainless steel that can be used in higher-heat, low-stress applications. Also called Alloy 410, this grade of stainless steel offers exceptional corrosion resistance, wear resistance, high strength and hardness. The most common hardenable stainless steel, 410 stainless steel is similar to AISI 4130 and is frequently used as filler metal in welding operations, in steam and gas turbine blades and buckets; and in a variety of mining and petroleum applications. Alloy 410 Configurations Available Altemp Alloys offers 410 stainless steel (UNS S41000) in the following:410 Stainless Steel ShapesSpecifications / ConfigurationsAdditional Information410 stainless steel pipes AMS 550 4ASTM-A-240 410 stainless steel Bars AMS 561 2AMS 5613 Common parts and applications using with 410 Stainless Steel: Automotive exhausts Stainless Steel tubes High-heat engine parts Stainless Steel flanges Medical, dental and surgical devices and instruments Stainless Steel Valve parts Oil well pump balls and seats Stainless Steel pipes Stainless Steel pipe fittings Wear surfaces Stainless Steel Fasteners including Stainless Steel bolts, Stainless Steel screws, Stainless Steel nuts and Stainless Steel bushings Separating screens and strainers Mine ladder rungs Stainless Steel bars Composition Carbon 0.15 max. Manganese 1.00 max. Phosphorus 0.040 max. Sulfur 0.030 max. Silicon 1.00 max. Chromium 11.50 – 13.50 In addition, Altemp Alloys carries a range of other stainless steel alloys, including 15-7 MO, 347 Stainless Steel, 15-5 PH, 321 Stainless Steel, 13-8 MO, 17-7 PH Stainless Steel, AM 350, 17-4 PH Stainless Steel and A-286. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

UNS S32760 Super Duplex stainless steel – with a microstructure of 50:50 austenite and ferrite, the steel has improved strength over ferritic and austenitic steel grades. With a higher than average Molybdenum and Chromium content, the material has greater heat and corrosion resistant qualities.  With reduced production costs when compared with equivalent austenitic and ferritic grades and with greater yield and tensile strength,UNS S32760 Super Duplex stainless steel is a cost effective solution for the consumer. It is conceivable that material thicknesses for a project may be reduced if UNS S32760 Super Duplex stainless steel is used, thus reducing cost without compromising quality. Benefits of UNS S32760 Super Duplex Stainless Steel Increased tensile & yield strength Good ductility and toughness SSC resistance Corrosion resistance is better than Duplex Cost effective Applications of UNS S32760 Super Duplex Stainless Steel UNS S32760 Super Duplex Stainless Steel is used in the oil and gas industry, on offshore platforms, in heat exchangers, UNS S32760 Super Duplex Stainless Steel Pipes, chemical processing equipment, pressure vessels and boilers. About UNS S32760 Super Duplex Stainless Steel For technical information about this Super Duplex Stainless Steel grade please refer to the chemical composition and mechanic properties tables below. Chemical CompositionUNS NoCSiMnPSCrMoNiNOtherS327600.0301.001.000.0300.01024.0/26.03.0/4.06.00/8.000.20/0.30Cu:0.50/1.00 W:0.50/1.00 Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Duplex Stainless Steel 2205 is a mixed microstructure of austenite and ferrite (50/50) which has improved strength over ferritic and austenitic stainless steel grades with similar corrosion resistance qualities. One of the main attractions of duplex stainless steel is cost – due to the materials increased yield strength it is often possible to reduce the thickness of material making it much cheaper than a comparative austenitic stainless steel grade. Also Duplex stainless steel has a lower alloy content reduces production costs. Certainly cost and weight savings without loss of performance is an attractive proposition to purchasers. Benefits of using UNS32205 Duplex Stainless Steel 2205 Corrosion resistance much better than that of Type 316 Greater tensile and yield strength Good ductility and toughness though not as good as austenitic grades Good stress corrosion cracking resistance (SSC) Opportunity for purchases to reduce their material costs without compromising on quality About Duplex Stainless Steel 2205 Duplex Stainless Steel 2205 is the most common duplex alloy which contains 22% chromium and 5% nickel. Please refer to the chemical composition and mechanic properties tables below. For information on “Super Duplex Stainless Steel” which provides higher corrosion resistance please click on the links to Super Duplex Stainless Steel grades at the top of this page. Chemical CompositionUNS NoGradeCSiMnPSCrMoNiNOtherS3220522050.0301.002.000.0300.02022.0/23.03.0/3.54.5/6.50.14/0.20–– Mechanical PropertiesUNS NoGradeProof Stress 0.2% (MPa)Tensile Strength (MPa)Elongation A5 (%)Hardness (Max)HBHRBS3220522054506202029331* * Rockwell C Scale Established in 2008, wilsonpipeline Pipe Industry Co., Limited is a professional organizer and one-stop-shop supplier for steel piping system products, including stainless steel pipe and tube, forged flange and fittings, butt-welding pipe fittings, elbow, tee, reducer, stub end, gaskets, fasteners, valves, Sanitary Services etc. in China. We have devoted to providing the best solutions of steel materials and industrial equipment for our respected customers. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

410 Stainless Steel Detailed Description 410 stainless steel is a martensitic stainless steel that provides good corrosion resistance plus high strength and hardness. It is magnetic in both the annealed and hardened conditions. A wide of properties can be achieved with different heat treatments. Applications requiring moderate corrosion resistance and high mechanical properties are ideal for this alloy. Stainless Steel Flanges, Stainless Steel Pipes, Stainless Steel Bars, AMS 5504, AMS 5505, ASTM A-240 Applications Stainless steel pipe fittings, hardware, stainless steel bars, stainless steel compressor parts, valve parts for oil fields, stainless steel fasteners, springs, pins, stainless steel flanges, stainless steel pipes. Chemistry Typical ElementWeight %C 0.15 Mn 1.00 Si 1.00 Cr 11.5-13.0 P 0.04 S 0.03 Mechanical Properties Properties Conditions T (°C)TreatmentDensity (×1000 kg/m3)7.825 Poisson’s Ratio0.27-0.3025 Elastic Modulus (GPa)20025 Tensile Strength (Mpa)485 25 annealed, hot finished (wire) moreYield Strength (Mpa)275 Elongation (%)20 Reduction in Area (%)45 Hardness (HRB)95 (max) 25 annealed (plate, sheet, strip) Forms – Stainless Steel Pipes, Stainless Steel Tubes – stainless steel squareround bars, stainless steel square bars, stainless steel hex bars, stainless steel angle bars, stainless steel flat bars, stainless steel channel bars, stainless steel T bars … Mechanical Properties at Room Temperature Properties: Annealed Ultimate Tensile Strength: 65 KSI min (450 MPa min) Yield Strength (0.2% offset): 30 KSI min (205 MPa min) Elongation: 20% min Hardness: Rb 88 max Properties: Tempered 410 stainless steel can be provided in the tempered condition. Mechanical Properties Corrosion Resistance Finishes # 1  –Hot rolled annealed and descaled. It is available in strip, foil and ribbon. It is used for applications where a smooth decorative finish is not required. # 2D  – Dull finish produced by cold rolling, annealing and descaling. Used for deep drawn parts and those parts that need to retain lubricants in the forming process. # 2B  –Smooth finish produced by cold rolling, annealing and descaling.  A light cold rolling pass is added after anneal with polished rolls giving it a brighter finish than 2D. #BA – Bright annealed cold rolled and bright annealed #CBA – Course bright annealed  cold rolled matte finish and bright anneal #2 – Cold Rolled # 2BA  – Smooth finish produced by cold rolling and bright annealing. A light pass using highly polished rolls produces a glossy finish. A 2BA finish may be used for lightly formed applications where a glossy finish is desired in the formed part. Polished – Various grit finish for specific polish finished requirements Wire Finishes XC – Extra clean, bright annealed or bright annealed and cold rolled Grease – Ultra bright finish for decorative applications Soap – Soap is not removed from tempered wire to act as a lubricant. Heat Treatment 410 stainless steel can be hardened by cold working and by heat treating. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Type 410 Stainless Steel is a martensitic stainless steel that provides good corrosion resistance plus high strength and hardness. It is magnetic in both the annealed and hardened conditions. A wide range of properties can be developed with different heat treatments. Product Forms: Stainless Steel Pipes, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Strip Specifications: ASTM A240 Chemical Composition:ElementType 410Carbon0.08 – 0.15Manganese1.00 max.Sulfur0.030 max.Phosphorus0.040 max.Silicon1.00 max.Chromium11.5 – 13.5Nickel0.75 max. Mechanical Properties:TypeYield Strength 0.2% offset (KSI)Tensile Strength (KSI)% Elongation (2″ Gauge length)Hardness Rockwell410 Ann30 min.65 min.20 min.HRB 96 Physical Properties:Density (lb./ in^2) @ RT 0.28Modulus of Elasticity in Tension (psi x 10^6) 29.0Specific Heat (BTU/o F/lb.)32 to 212 oF0.11Thermal Conductivity (BTU/hr/ft^2/ft)212oF14.4 932oF16.6Mean Coefficient of Thermal Expansion (in. x 10^-6 per o F)32 to 212oF5.5 32 to 1,200oF6.5Electrical Resistivity (micro ohms – cm)at 70oF22.5 Typical Applications: Collector rings, airplane exhaust stacks, annealing box covers, stainless steel flanges, stainless steel pipe fittings, jet engineparts,expansion joints, stainless steel tubes, stainless steel bars, stainless steel angle bars flexible metal hose and bellows. Processing: Annealing: Heat slowly to 1500 -1650°F, cool to 1100°F in furnace, air cool. Process Annealing: Heat to 1350 -1450°F, air cool. Hardening: Heat to 1700 – 1850°F, air cool or oil quench. Follow by stress-relief or temper. Stress Relieving: Heat at 300 – 800°F for 1 to 2 hours, air cool. Tempering: Heat to 1100 – 1400°F for 1 to 4 hours, air cool. Forming: Type 410 Stainless Steel has reasonably good cold working properties and can be moderately drawn and formed in the annealed condition. Welding: The martensitic alloys have limited weldability due to their hardenability. Corrosion: Type 410 Stainless Steel provides good corrosion resistance to air, water and some chemicals. It shows satisfactory resistance to nitric acid, concentrated sulfuric acid, dilute acetic acid and naphtha. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

wilsonpipeline Pipe Industry Co., Limited is a global stainless steel products supplier and Manufacturer, supplying the engineering, power generation, petrochemical, oil & gas and nuclear industries. Partnerships integrating the resources of the worlds most technically advanced steel mills enable wilsonpipeline to provide a single competitive source for the distribution of stailess steel products worldwide. Stainless Steel Bars Stainless steel Bars is often referred to as ‘corrosion-resistant steel’ – it does not stain, corrode or rust as easily as normal carbon steel. It would however be misleading to say it is corrosion-proof. It differs significantly from standard carbon steel due to the amount of chromium present, which limits surface corrosion unlike carbon steel which will rust when exposed to air and any moisture in the atmosphere. Due to its anti-oxidation qualities, stainless steel is often a popular solution. Applications of Stainless Steel Bars Where low maintenance and corrosion resistance is required, stainless steel bars are a natural choice and are used in a perse range of applications from modern architecture for cladding or fascias, to the food hygiene industry due to its anti-bacterial qualities. Different Grades of Stainless Steel Bars wilsonpipeline supplies stainless steel in a wide variety of grades and aesthetic finishes. There are many options available – for example adding carbon during the forming process will make the stainless steel more durable and stronger too. Variety of Stainless Steel Bars wilsonpipeline can supply stainless steel in stainless steel pipes, stainless steel flanges, stainless steel pipe fittings and stainless steel pipe bars and ship the material worldwide. Industrial Use of Stainless Steel Bars Examples of industrial uses of stainless steel bars are listed below. Chemical and fuel tankers Chemical and petro-chemical bars Food processing and pharmaceutical industries where clean environments are required Construction, modern architecture Stainless Steel Supply Services As a major stainless steel supplier, wilsonpipeline’s supply services includes the following. major stockholding global shipping variety of finishes available heat resistant qualities when specified quick turnaround accurate ‘in-house’ cutting and profiling service Stainless Steel Bars Specifications The different grades of stainless steel bars are outlined in the following. Stainless Steel: 304 / 304L / 304H 316 / 316L / 316H / 316Ti 321 / 321H Duplex Stainless Steel/Super Duplex Stainless Steel: S31803 S32750/S32760 To find out more about wilsonpipeline’s services and our range of stainless steel bars please vist wilsonpipeline. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Super Duplex Stainless Steel like Duplex Stainless Steel, is a mixed microstructure of austenite and ferrite (50/50) which has improved strength over ferritic and austenitic steel grades. The main difference is that Super duplex stainless steel has a higher Molybdenum and Chromium content which gives the material greater corrosion resistance. Super Duplex Stainless Steel has the same benefits as its counterpart – it has lower production costs when compared with similar ferritic and austenitic stainless steel grades and due to the materials increased tensile and yield strength, in many cases this gives the purchaser the welcomed option of purchasing smaller thicknesses without the need to compromise on quality and performance. Benefits of UNS S32750 Super Duplex Stainless Steel 2507 Improved corrosion resistance in comparison to Duplex Stainless Steel Greater tensile and yield strength Good ductility and toughness Good stress corrosion cracking resistance (SSC) Opportunity for purchases to reduce their material costs without compromising on quality Applications of UNS S32750 Super Duplex Stainless Steel 2507 Super Duplex Stainless Steel is used in the oil and gas industry, on offshore platforms, in heat exchangers, super duplex stainless steel 2507 flange,chemical processing equipment pressure vessels and boilers. About UNS S32750 Super Duplex Stainless Steel 2507 2507 is the most common Super Duplex Stainless Steel which contains 24% chromium and a minimum of 3% molybdenum. Please refer to the chemical composition and mechanic properties tables below. Chemical CompositionUNS NoGradeCSiMnPSCrMoNiNOtherS3275025070.0300.801.200.0350.02024.0/26.03.0/5.06.00/8.000.24/0.32Cu:0.50 Mechanical PropertiesUNS NoGradeProof Stress 0.2% (MPa)Tensile Strength (MPa)Elongation A5(%)Hardness MaxHBHRBS3275025075507951531032* Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

This article provides the alternative specifications for the Australian food industry service. Such specifications include: ASTM A554 “Specification for welded stainless steel mechanical tubing” ASTM A270 “Specification for seamless and welded austenitic stainless steel sanitary tubing” ASTM A269 “Specification for seamless and welded austenitic stainless steel tubing for general service” ASTM A249 “Specification for welded austenitic steel boiler, super heater, heat exchanger, and condenser tubes” AS 1528.1 “Specification for stainless steel tubing for the food industry” AS1528 was revised in 2001 by key stakeholders in the Australian food manufacturing and stainless steel tube industries. AS 1528 is unique, in that it covers all the associated fittings in addition to the stainless steel tube. Specification Comparison Material All specifications pertain to common grades, such as grades 304, 304L, 316 and 316L. AS1528.1 covers all grades of duplex and austenitic stainless steel listed in ASTM A240. Manufacture All specifications need fusion-welded products without filler metals. Specifications such as ASTM A270, ASTM A269 and AS 1528 also cover seamless products. Dimensional Tolerances Wall Thickness ASTM A554 requires ±10% of nominal – no nominal thicknesses are stipulated. ASTM A270 requires ±12.5% of nominal – no nominal thicknesses are stipulated. ASTM A269 requires ±10% of nominal for sizes over ½” – no nominal thicknesses are stipulated. ASTM A249 requires ±10% of nominal – no nominal thicknesses are stipulated. AS 1528 specifies nominal thicknesses of 1.6mm for all outside diameters, (ODs) except 2 mm for 203.2 mm OD; other thicknesses can be specified by purchasers. Standard tolerance is +nil, -0.10mm. The all-minus tolerance recognizes the usual practice for stainless stainless steel tube, to all specifications, to be produced towards the lower limit of the tolerance range. A range of between 1.52 and 1.58 mm is typical. This tolerance also applies to stainless steel tube fittings. Outside Diameter Table 1. Specification requirements for standard inch series OD stainless steel tube sizesOutside Diameter Requirements (mm)DiameterA249A269A270A554*AS 1528*25.4±0.15±0.13+0.05/-0.20±0.13±0.1338.1±0.15±0.25+0.05/-0.20±0.15±0.2550.8±0.25±0.25+0.05/-0.28±0.18±0.2563.5±0.3±0.25+0.05/-0.28±0.25±0.2576.2±0.38±0.25+0.08/-0.30±0.25±0.25101.6±0.38±0.38+0.08/-0.38±0.38±0.38 * ASTM A554 tolerances for the weld bead removed condition. * AS1528 also covers OD sizes 12.7, 19.0, 31.8, 127.0, 152.4 and 203.2mm All these stainless steel tube specifications provide limits for wall thickness and OD. The inside diameters are not mentioned separately. Surface Finish The surface finish properties of various specifications, recommended for Australian food industry services, are as follows: ASTM A249 and ASTM A269 require surfaces that are free of scales and rust. Annealing of the stainless steel tube is usually carried out in a controlled environment, and this “bright annealed” finish is considered acceptable. ASTM A270 needs selection of both external and internal surfaces. The possible conditions include mill finish, abrasive polishing with 80, 120, 180 or 240 grit, special polishing or electropolishing. Surface finishes can be specified in terms of Ra values without any limits. ASTM A554 specifies “direct off mill” or “free of scale” finish as standard. Special finishes, if required, need to be mentioned in the order. Thus a large quantity of A554 tube is supplied in buffed or externally polished conditions. AS1528 covers the external surface “buff polished” or “as produced”. The internal surface needs to be 2B finish, quoted as typically 0.3µm Ra. Studies suggest that the typical roughness ranges from 0.10 to 0.20 µm Ra for 1.6mm 2B coil. Precautions must be taken to prevent significant degradation of roughness during the manufacture of stainless steel tube. Weld Bead Listed below are the weld bead procedures for different steel grades: The handling products used in the food industry require a stainless steel tube without weld bead remnant on the inner surface. ASTM A249 requires the weld to be cold-worked after welding, and before final heat treatment. ASTM A269 does not require any cold-working or weld bead control. ASTM A270 does not require weld bead. ASTM A554 can be supplied with the weld bead left on, and hence it complies with the “Bead Removed” option of A554. AS1528 requires removal of the weld bead. There is also a requirement that the internal surface needs to be smooth, with no lack of weld penetration and no crevices adjacent to welds. Heat Treatment The following stainless steel grades can be heat-treated: ASTM A249, ASTM A269 and ASTM A27 specify that all materials can be furnished in the heat-treated condition. Heat-treatment usually involves annealing methods, such as solution annealing or solution treatment. In practice, heat-treatment is not a basic requirement for food industry applications. ASTM A554 is usually supplied in “as welded” condition, i.e. no heat-treatment required after stainless steel tube forming. AS1528 allows the purchaser to specify either annealed or un-annealed conditions of steel products. Mechanical Properties The mechanical properties of various stainless steel grades, commonly used in food industries, are given below: ASTM A249 requires extensive mechanical testing for use in critical environments in boilers or heat exchangers. ASTM A269 requires reverse flattening, plus flange and hardness tests. It does not require tensile testing. ASTM A270 requires a reverse flattening test only. ASTM A554 does not require mechanical testing as standard. AS1528 requires the stainless steel tube to be made of strips that comply with ASTM A240. It does not require tensile or hardness testing. Non-Destructive Inspection The non-destructive inspection procedures for different steel grades are listed below: ASTM A249, ASTM A269, ASTM A270 and AS1528.1 all require 100% hydrostatic or eddy current testing. ASTM A554 includes a supplementary requirement that deals with the possibility of non-destructive testing. However, this is applicable for ASTM A554 tube. Which Specification The following section provides a summary on each specification employed in food industries: ASTM A269 again requires annealed tube. Conversely, it does not specify internal weld bead removal, which generally is a food industry requirement. ASTM A269 is a stock item, and it proves uncompetitive against un-annealed tube. ASTM A270 also requires the stainless steel tube in the annealed condition, and it describes nothing about weld bead. The finish options available in this specification are very comprehensive. ASTM A554 is intended for mechanical applications, and not for pressure containment or sanitary use. AS1528 is the safest and most cost-effective option. It is specifically employed in food industries, as it specifies the features necessary to achieve high integrity lines for hygienic applications without requiring expensive mechanical testing. Annealing can be done if required, and surface finishes can be further specified. Batch traceability marking, used to verify many food and pharmaceutical plants, is necessary. Another key benefit is the presence of matching specifications for stainless steel tube fittings. ASTM A249 specifies weld bead removal. This requirement can be met from other standards. ASTM A249 does not require annealing in most food applications. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steels are most commonly used for their corrosion resistance. The second most common reason stainless steels are used is for their high temperature properties; stainless steels can be found in applications where high temperature oxidation resistance is necessary, and in other applications where high temperature strength is required. The high chromium content which is so beneficial to the wet corrosion resistance of stainless steels are also highly beneficial to their high temperature strength and resistance to scaling at elevated temperatures. Scaling Resistance Resistance to oxidation, or scaling, is dependent on the chromium content in the same way as the corrosion resistance is, as shown in the graph below. Most austenitic steels, with chromium contents of at least 18%, can be used at temperatures up to 870°C and Grades 309, 310 and 2111HTR (UNS S30815) even higher. Most martensitic and ferritic steels have lower resistance to oxidation and hence lower useful operating temperatures. An exception to this is the ferritic grade 446 – this has approximately 24% chromium, and can be used to resist scaling at temperatures up to 1100°C. Table 1 shows the approximate maximum service temperatures at which the various grades of stainless steels can be used to resist oxidation in dry air. Note that these temperatures depend very much on the actual environmental conditions, and in some instances substantially lower temperatures will result in destructive scaling. Table 1. Maximum service temperatures in dry air, based on scaling resistance (ref: ASM Metals Handbook) Grade Intermittent (°C) Continuous (°C) 304 870 925 309 980 1095 310 1035 1150 316 870 925 321 870 925 410 815 705 416 760 675 420 735 620 430 870 815 2111HTR 1150 1150 Creep Strength The high temperature strength of materials is generally expressed in terms of their “creep strength” – the ability of the material to resist distortion over long term exposure to a high temperature. In this regard the austenitic stainless steels are particularly good. Design codes such as Australian Standard AS1210 “Pressure Vessels” and AS4041 “Pressure Piping” (and corresponding codes from ASME and other bodies) also stipulate allowable working stresses of each grade at a range of temperatures. The low carbon versions of the standard austenitic grades (Grades 304L and 316L) have reduced strength at high temperature so are not generally used for structural applications at elevated temperatures. “H” versions of each grade (eg 304H) have higher carbon contents for these applications, which results in significantly higher creep strengths. “H” grades are specified for some elevated temperature applications. Although the duplex stainless steels have good oxidation resistance due to their high chromium contents, they suffer from embrittlement if exposed to temperatures above about 350°C, so they are restricted to applications below this. Both martensitic and precipitation hardening families of stainless steels have high strengths achieved by thermal treatments; exposure of these grades at temperatures exceeding their heat treatment temperatures will result in permanent softening, so again these grades are seldom used at elevated temperatures. Structural Stability The problem of grain boundary carbide precipitation was discussed under intergranular corrosion. This same phenomenon occurs when some stainless steels are exposed in service to temperatures of 425 to 815°C, resulting in a reduction of corrosion resistance which may be significant. If this problem is to be avoided the use of stabilised grades such as Grade 321 or low carbon “L” grades should be considered. A further problem that some stainless steels have in high temperature applications is the formation of sigma phase. The formation of sigma phase in austenitic steels is dependent on both time and temperature and is different for each type of steel. In general Grade 304 stainless steel is practically immune to sigma phase formation, but not so those grades with higher chromium contents (Grade 310) with molybdenum (Grades 316 and 317) or with higher silicon contents (Grade 314). These grades are all prone to sigma phase formation if exposed for long periods to a temperature of about 590 to 870°C. Sigma phase embrittlement refers to the formation of a precipitate in the steel microstructure over a long period of time within this particular temperature range. The effect of the formation of this phase is to make the steel extremely brittle and failure can occur because of brittle fracture. Once the steel has become embrittled with sigma it is possible to reclaim it by heating the steel to a temperature above the sigma formation temperature range, however this is not always practical. Because sigma phase embrittlement is a serious problem with the high silicon grade 314, this is now unpopular and largely replaced by high nickel alloys or by stainless steels resistant to sigma phase embrittlement, particularly 2111HTR (UNS S30815). Grade 310 is also fairly susceptible to sigma phase formation in the temperature range 590 to 870°C, so this “heat resistant” grade may not be suitable for exposure at this comparatively low temperature range and Grade 321 is often a better choice. Environmental Factors Other factors which can be important in the use of steels for high temperature applications are carburisation and sulphidation resistance. Sulphur bearing gases under reducing conditions greatly accelerate the attack on stainless alloys with high nickel contents. In some instances Grade 310 has given reasonable service, in others grade S30815, with a lower nickel content is better, but in others a totally nickel-free alloy is superior. If sulphur bearing gases are present under reducing conditions it is suggested that pilot test specimens be first run under similar conditions to determine the best alloy. Thermal Expansion A further property that can be relevant in high temperature applications is the thermal expansion of the particular material. The coefficient of thermal expansion is expressed in units of proportional change of length for each degree increase in temperature, usually x10-6/°C, μm/m/°C, or x10-6cm/cm/°C, all of which are identical units. The increase in length (or diameter, thickness, etc) can be readily calculated by multiplying the original dimension by the temperature change by the coefficient of thermal expansion. For example, if a three metre long Grade 304 bar (coefficient of expansion 17.2 μm/m/°C) is heated from 20°C to 200°C, the length increases by: 3.00 x 180 x 17.2 = 9288 μm = 9.3 mm The coefficient of thermal expansion of the austenitic stainless steels is higher than for most other grades of steel, as shown in the following table. Table 2. Coefficient of thermal expansion – average values over 1-100°C Coefficient of Thermal Expansion (x10-6/°C) Carbon Steels 12 Austenitic Steels 17 Duplex Steels 14 Ferritic Steels 10 Martensitic Steels 10 * or micrometres/metre/°C This expansion coefficient not only varies between steel grades, it also increases slightly with temperature. Grade 304 has a coefficient of 17.2 x 10-6/°C over the temperature range 0 to 100°C, but increases above this temperature The effect of thermal expansion is most noticeable where components are restrained, as the expansion results in buckling and bending. A problem can also arise if two dissimilar metals are fabricated together and then heated; dissimilar coefficients will again result in buckling or bending. In general the quite high thermal expansion rates of the austenitic stainless steels mean that fabrications in these alloys may have more dimensional problems than similar fabrications in carbon or low alloy steels, in ferritic, martensitic or duplex stainless steels. The non-austenitic stainless steels also have somewhat higher thermal conductivities than the austenitic grades, which may be an advantage in certain applications. Localised stresses from expansion during heating and cooling can contribute to stress corrosion cracking in an environment which would not normally attack the metal. These applications require design to minimise the adverse effects of temperature differentials such as the use of expansion joints to permit movement without distortion and the avoidance of notches and abrupt changes of section. Source: Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless Steels Sorting and identification tests are non-destructive, inexpensive and rapid procedures, usually carried out on different grades of stainless steels. Sorting of product procedures is particularly useful when Stainless Steel bars of Stainless Steel grade 303 and 304 have been accidentally stored together, or when Stainless Steel grade 304 and Stainless Steel 316 sheet offcuts are mixed. Although these tests are extremely useful, they have certain limitations too. It is difficult to sort one heat from another of the same grade using these tests. For instance, type stainless steel 304 cannot be readily sort from stainless steel 321, stainless steel 316 from stainless steel 316L or stainless steel 304 from stainless steel 304L. Apart from these simple tests, there are more complex tests that involve several chemical reagents for product sorting and grade identification, hardness tests for the products, and tests for determining the response of products to heat treatment. Full spectrometric analysis of the product can be carried out if these simple tests are not found to be adequate. Upon retaining the original product identification, such as grade/heat/specification markings, tags, stickers or product colour codes, these sorting tests may not be required. Tests The table below provides the tests for the sorting and identification of stainless steels: Table 1. Tests for the identification and sorting of stainless steels Test What Can Be Sorted Method Precautions Magnetic Response Austenitic (300 Series) stainless steels can be sorted from other types of stainless steels. All other types of steels such as the precipitation hardening, martensitic, duplex and Ferritic stainless steels are sensitive to magnet fields. The austenitic manganese steels (e.g., “P8”) are the only non-magnetic group of steels. Observe response when a permanent magnet is made to contact with the steel. Some austenitic grades, particularly stainless steel 304, are attracted when cold-worked, e.g. by bending, forming or rolling. When cold-worked, certain austenitic steels (e.g. stainless steel grade 304) gain a magnetic response. This response can be removed by stress relieving the steels at cherry-red heat. However, the stress relieving procedure may tend to sensitize the steel. Therefore, care must be taken to avoid stress relief on a materia, that is to be used in corrosive conditions. Full annealing can be performed. Nitric Acid Reaction Stainless steels from non-stainless steels. 1. Either, place a drop of strong nitric acid on the steel surface, or the steel in acid solution at room temperature. 2. Test standard samples, such as stainless and non-stainless steel samples, in the same way. 3.When non-stainless steels are affected by nitric reaction, a pungent brown fume is generated. Stainless steels, however, remain unaffected. The results of both the samples can be compared. 4. Samples need to be thoroughly washed. Strong nitric acid is corrosive and harmful to skin. Hence, clean thoroughly if the skin is brought into contact with the acid. Avoid inhaling brown fume. Safety glasses should be used. Molybdenum Spot Test (Mo) Stainless steels containing a significant amount of molybdenum (Mo) from the steels that are free of Mo. Type 404 steels can also be sorted from type 316 steels. Some of the Mo grades, which provide a positive response to this test, include stainless steel grade 316, stainless steel grade 316L, stainless steel grade 317, stainless steel grade 317L, stainless steel grade 444, stainless steel grade 904L, stainless steel grade 2205, “6-Mo” grades, grade 4565S and all “super duplex” grades (e.g. S32760 / Zeron 100 / S32750 / 2507 / S32550 / Alloy 255 / S32520 / UR52N+). Other similar grades, having less quantities of Mo, will also show positive response. 1. Clean the surface of the steel using abrasive paper, followed by degreasing and drying if necessary. 2. Use “Decapoli 304/316” solution. Shake well before use, and then place a drop of solution on the steel. 3. Place a drop of solution on standard stainless steel grades 304 and stainless steel 316 samples. 4. Presence of Mo in the steel can be confirmed by the darkening of the yellow drop in 2 to 4 min. Compare the indications of test samples with that of standard samples. 5. Wash or wipe the samples. Avoid contact of test solution on skin and, particularly, eyes. Avoid exposure of skin and eyes to the test solution. Clean the skin thoroughly in case of contact. Reliable results can be obtained only if all the samples are maintained at the same temperature. Low temperatures should be avoided. Some heats of “Mo-free” stainless steels, such as stainless steel grade 304, contain small amounts of Mo, sufficient enough to stimulate a slight reaction. Sulphur Spot Test (S) Stainless and plain carbon steels having at least 0.1% of sulphur, i.e. free-machining grades. (e.g. stainless steel grades S1214, stainless steel S12L14, stainless steel 303, stainless steel 416, stainless steel 430F) can be sorted from non-free-machining steels. Ugima 303 contains high sulphur content and, hence, it will initiate a positive reaction. However, the sulphur content of Ugima 304 and Ugima 316 is less than that of their standard (non-Ugima) equivalents and, hence, no positive reactions can be observed in these grades. 1. Clean the surface of the steel using abrasive paper, followed by degreasing and drying if necessary. 2. Prepare standard samples e.g. known stainless steel grades CS1020 and stainless steel S1214, or stainless steel grades 304 and stainless steel 303, in the same way. 3. Soak photographic paper in 3% sulphuric acid solution for about 3 min. 4. Press the prepared steel surfaces on the photographic paper surface for 5 s. 5. A dark brown stain indicates the presence of significant quantities of sulphur in the test sample. Compare the indications of test samples with that of standard samples. 6. Wash or clean the samples. Avoid exposure of skin and eyes to the test solution. Clean the skin thoroughly in case of contact. Safety glasses should be used. Good results can be obtained by maintaining the samples at the same temperature. Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)