Search Results

Duplex Duplex is a material that has approximately equal amounts of austenite and ferrite. These combine excellent corrosion resistance with high strength. Mechanical properties are approximately double those of singular austenitic steel and resistance to stress corrosion cracking is superior to type 316 stainless steel in chloride solutions. Duplex material has ductile or brittle transition at approximately -50 degrees. High Temperature use is usually restricted to a maximum temperature of 300 degrees for indefinite use due to embrittlement. Duplex stainless steels have a mixed microstructure of austenite and ferrite, the aim being to produce a 50/50 mix, although in commercial alloys, the mix may be 40/60 respectively. Duplex steels have improved strength over austenitic stainless steels and also improved resistance to localised corrosion, particularly pitting, crevice corrosion and stress corrosion cracking. They are characterised by high chromium (19–28%) and molybdenum (up to 5%) and lower nickel contents than austenitic stainless steels. The most used Duplex Stainless Steel are the 2205 (22% Chromium, 5% Nickel) and 2507 (25% Chromium, 7% Nickel); the 2507 is also known as “Super Duplex” due to its higher corrosion resistance. Super Duplex Super duplex pipe is known to have better stress corrosion, cracking resistance and mechanical properties. The high corrosion resistance of super duplex pipeline supplies makes them ideal for onshore and offshore environments in oil and gas applications. Please see our industry pages for more information regarding the implications of Super Duplex piping. Super Duplex is an Austenitic Ferritic Iron Chromium – Nickel Alloys with Molybdenum addition. It has good resistance to pitting and a very high tensile strength and high resistance too stress corrosion cracking at moderate temperatures compared to that of conventional austenitic stainless steels.

Chemical Composition Fe, <0.03% C, 21-23% Cr, 4.5-6.5% Ni, 2.5-3.5% Mo, 0.8-2.0% N, <2% Mn, <1% Si, <0.03% P, <0.02% S Introduction Duplex 2205 stainless steel (both ferritic and austenitic) is used extensively in applications that require good corrosion resistance and strength. The S31803 grade stainless steel has undergone a number of modifications resulting in UNS S32205, and was endorsed in the year 1996. This grade offers higher resistance to corrosion. At temperatures above 300°C, the brittle micro-constituents of this grade undergo precipitation, and at temperatures below -50°C the micro-constituents undergo ductile-to-brittle transition; hence this grade of stainless steel is not suitable for use at these temperatures. Key Properties The properties that are mentioned in the below tables pertain to flat rolled products such as plates, sheets and coils of the ASTM A240 or A240M. These may not be uniform across other products such as bars and pipes. Composition Table 1 provides the compositional ranges for grade 2205 duplex stainless steel. Table 1 – Composition ranges for 2205 grade stainless steels Grade C Mn Si P S Cr Mo Ni N 2205 (S31803) Min Max – 0.030 – 2.00 – 1.00 – 0.030 – 0.020 21.0 23.0 2.5 3.5 4.5 6.5 0.08 0.20 2205 (S32205) Min Max – 0.030 – 2.00 – 1.00 – 0.030 – 0.020 22.0 23.0 3.0 3.5 4.5 6.5 0.14 0.20 Mechanical Properties The typical mechanical properties of grade 2205 stainless steels are listed in the table below. Grade S31803 has similar mechanical properties to that of S32205. Table 2 – Mechanical properties of 2205 grade stainless steels Grade Tensile Str (MPa) min Yield Strength 0.2% Proof (MPa) min Elongation (% in 50mm) min Hardness Rockwell C (HR C) Brinell (HB) 2205 621 448 25 31 max 293 max Physical Properties The physical properties of grade 2205 stainless steels are tabulated below. Grade S31803 has similar physical properties to that of S32205. Table 3 – Physical properties of 2205 grade stainless steels Grade Density (kg/m3) Elastic Modulus (GPa) Mean Co-eff of Thermal Expansion (μm/m/°C) Thermal Conductivity (W/m.K) Specific Heat 0-100°C ( J/kg.K) Electrical Resistivity (nΩ.m) 0-100°C 0-315°C 0-538°C at 100°C at 500°C 2205 782 190 13.7 14.2 – 19 – 418 850 Grade Specification Comparison Table 4 provides the grade comparison for 2205 stainless steels. The values are a comparison of functionally similar materials. Exact equivalents may be obtained from the original specifications. Table 4 – Grade specification comparisons for 2205 grade stainless steels Grade UNS No Old British Euronorm Swedish SS Japanese JIS BS En No Name 2205 S31803 / S32205 318S13 – 1.4462 X2CrNiMoN22-5-3 2377 SUS 329J3L Possible Alternative Grades Given below is a list of possible alternative grades, which may be chosen in place of 2205. Table 5 – Grade specification comparisons for 2205 grade stainless steels Grade Reasons for choosing the grade 904L Better formability is needed, with similar corrosion resistance and lower strength. UR52N+ High resistance to corrosion is required, e.g. resistance to higher temperature seawater. 6%Mo Higher corrosion resistance is required, but with lower strength and better formability. 316L The high corrosion resistance and strength of 2205 are not needed. 316L is lower cost. Corrosion Resistance Grade 2205 stainless steel exhibits excellent corrosion resistance, much higher than that of grade 316. It resists localized corrosion types like intergranular, crevice and pitting. The CPT of this type of stainless steel is around 35°C. This grade is resistant to chloride stress corrosion cracking (SCC) at temperatures of 150°C. Grade 2205 stainless steels are apt replacements to austenitic grades, especially in premature failure environments and marine environments. Heat Resistance The high oxidation resistance property of Grade 2205 is marred by its embrittlement above 300°C. This embrittlement can be modified by a full solution annealing treatment. This grade performs well at temperatures below 300°C. Heat Treatment The best suited heat treatment for this grade is solution treatment (annealing), between 1020 – 1100°C, followed by rapid cooling. Grade 2205 can be work hardened but cannot be hardened by thermal methods. Welding Most standard welding methods suit this grade, except welding without filler metals, which results in excess ferrite. AS 1554.6 pre-qualifies welding for 2205 with 2209 rods or electrodes so that the deposited metal has the right balanced duplex structure. Adding nitrogen to the shielding gas ensures that adequate austenite is added to the structure. The heat input must be maintained at a low level, and the use of pre or post heat must be avoided. The co-efficient of thermal expansion for this grade is low; hence the distortion and stresses are lesser than that in austenite grades. Machining The machinability of this grade is low due to its high strength. The cutting speeds are almost 20% lower than that of grade 304. Fabrication The fabrication of this grade is also affected by its strength. Bending and forming of this grade requires equipment with larger capacity. Ductility of grade 2205 is lesser than austenitic grades; therefore, cold heading is not possible on this grade. In order to carry out cold heading operations on this grade, intermediate annealing should be carried out. Applications Some of the typical applications of duplex steel grade 2205 are listed below: Oil and gas exploration Processing equipment Transport, storage and chemical processing High chloride and marine environments Paper machines, liquor tanks, pulp and paper digesters

Duplex 2304 is a 23% chromium, 4% nickel, molybdenum-free duplex stainless steel whose structure is a balance of ferritic and austenitic. It has general corrosion resistance similar or better than Alloys 304L and 316L but with yield strength nearly double that of austenitic stainless steels. Its duplex microstructure and low nickel and high chromium contents also allows Duplex 2304 to demonstrate improved stress corrosion resistant properties compared to 304 and 316. It is typically suitable for all applications in the -58oF to 572oF (-50oC to 300oC) temperature range and is designed to feature high mechanical strength, good weldability, good corrosion resistance, high resistance to stress corrosion cracking, good machinability, low thermal expansion, good fatigue properties, high thermal conductivity, and easy fabrication. Specifications: UNS S32304 Applications: Duplex 2304 is generally used in the same applications in which Alloys 304 and 316L are used. Some examples of these applications include: Chloride containing environments Welded pipe systems within the Pulp and Paper, Chemical and Petrochemical, and Water Treatment industries Transportations Heat exchanger tubes Architecture, building, construction Pressure vessels Caustic solutions, organic acids Food industry Standards: ASTM/ASME: UNS S32304 EURONORM: FeMi35Cr20Cu4Mo2 DIN: 2.4660 Corrosion Resistance: Due to its high chromium content of 23%, the corrosion resistance properties of Duplex 2304 are practically equivalent to those of Alloy 316L Its duplex microstructure and low nickel and high chromium contents allows Duplex 2304 to have improved stress corrosion resistance properties compared to the 304L and 316L standard austenitic grades. More resistant to pitting and crevice corrosion resistance that Alloy 316L Outperforms Alloys 304L and 316L in stress corrosion cracking resistance in chloride containing aqueous solutions Its corrosion rate in boiling nitric acid (65%) is higher than that of Alloy 316L Its high yield strength allows Duplex 2304 to perform well in abrasion/corrosion applications Structure Microstructure of Duplex 2304 is very stable compared to molybdenum containing duplex stainless steels Contains approximately equal amounts of ferritic and austenitic in microstructure after annealing in a temperature about Weldability Can be successfully welded by TIG manual and automatic, PLASMA, MIG, SMAW, SAW, FCAW Duplex microstructure renders the alloy less sensitive to hot cracking Pre-heating and post welding is not required Filler metal should be a balanced ferrite/austenitic type Machinability Exhibits improved machinability properties particularly when considering drilling Low speeds and high feeds will minimize this alloys tendency to work harden Composition C Cr Fe Mn Si S P Ni Cu N Duplex 2304 0.03 max min: 21.5 max:24.5 Bal. 2.5 max 1.0 max 0.03 max 0.04 maxmin:3.0 max:3.5 min:0.05 max: 2.0 min: 0.05 max: 2.0 Mechanical Properties Grade Tensile Strength ksi (MPa) min Yield Strength 0.2% offset ksi (MPa) min Elongation (% in 50mm) min Hardness (Brinell) MAX Hardness (Rockwell B) MAX Duplex 2304 87 (600) 58 (400) 25 293 31j Physical Properties Duplex 2304 Density at 68°F (20°C) 0.28 lbm/in3 7800 kg/cm3 Coefficient of Thermal Expansion ax10-6°C-1 68°F to: 212°F (20 -100°C) 13 68°F to 392°F (20 -200°C) 13.5 68°F to 572°F (20 -300°C) 14 Thermal Conductivity W.m-1.K-1 at 68°F (20°C) 17 at 212°F (100°C) 18 at 392°F (200°C) 19 at 572°F (300°C) 20 Electrical Resitivity (µ_ cm) at 68°F (20°C) 80 at 212°F (100°C) 92 at 392°F (200°C) 100 at 572°F (300°C) 105 Specific Heat (Btu/lb/°F) 32°F to: 212°F (20 -100°C) 0.11

Commonly found in plumbing applications, metal flanges provide a quick and easy method for joining lengths of pipe to one another. A flange consists of an external ring around one end of a structure, pipe, or tube that contains matching boltholes for easy assembly. In contrast, pipes that require joining but lack any flanges normally involve either welding or soldering as the joining method. There are several different types of metal flanges available to cover a wide variety of applications. These include the copper flanges, iron flanges, Super Duplex Stainless Steel Flanges, and stainless steel flanges; these are implemented as structural flanges, plumbing flanges, and even microwave flanges. The types of metal flanges one may encounter often depends on their applications or uses. For example, water pipes generally use a copper or stainless steel flange, since a ductile ironflange can fail over time due to the natural result of rust forming when water reacts with iron. In other words, the product passing through any given flanged system dictates the appropriate materials used in the construction of the flanges, as well as in the tubing or piping itself. Since such a wide variety of applications exists, one would expect a challenge in matching up specific sizes of metal flanges. A system of uniformity, however, helps make this task rather simple. In the U.S., a classification system from the American Society for Mechanical Engineers (ASME) helps to discern between these choices by providing a set of standards to follow when certain projects require it. For example, when a plumber or other mechanical contractor needs to repair or replace sections of an established plumbing system, any metal flanges he or she encounters are already classified into certain sizes. This makes replacement as easy as ordering the appropriate ASME flanges. ASME is only an American piping standard, however, while other countries typically have their own classification systems. For example, the PN/DIN classification is used in many parts of Europe; the JIS/KS classification in Japan or Korea; and the BS10 in Britain or Australia. While anASME flange will mate to another ASME flange, it is unlikely that it would match one from another country’s classification system. The types of metal flange designs may also change with each application. For example, high-pressure connections may incorporate a “tongue-and-groove” interface. An application of this sort consists of two mating metal flanges protruding slightly into another flange, which greatly reduces the chances of pressure seeping out of the connection. This can be crucial if the product leaking out happens to be something dangerous, like a flammable gas.

LDX 2101 is a duplex (austenitic-ferritic) stainless steel with relatively low contents of alloying elements. The grade has high mechanical strength, similar to that of other duplex grades. Its good corrosion resistance is on par with that of most standard stainless steel grades. Combined, these properties can be utilised to optimise design with respect to strength, maintenance, durability and long-term cost efficiency. LDX 2101 main characteristics: High strength – approximately twice as high proof strength as austenitic stainless steels ASTM 304 and 316 Very good resistance to stress corrosion cracking Good resistance to general corrosion and pitting High energy absorption Physical properties that offer design advantages Ease of fabrication and good toughness Very good weldability Applications General-purpose applications and environments: Building and construction Storage tanks Reinforcement bars Water piping Specification UNS: ASTM/ASTE S32101 Microstructure The balanced chemical composition of LDX 2101 results in a microstructure containing approximately equal amounts of ferrite and austenite after annealing at a temperature of 1050°C (1920oF). Due to its relatively low alloying content, LDX 2101 is less prone to precipitaition of intermetallic phases than other duplex steels. The high nitrogen content results in rapid re-formation of austenite in weld thermal cycles. * LDX 2101 is a registered trademark owned by Outokumpu Stainless AB Standards UNS S32101 Chemical composition (nominal) %CSiMnPSCrNiNMo0.0301.05.00.040.0321.51.50.220.3 Mechanical properties Mechanical properties LDX 2101 has high mechanical strength due to its duplex microstructure and high nitrogen content. In Table 1 the minimum and typical values for the grade are presented. The mechanical properties at elevated temperatures are shown in Table 2.Minimum valuesTypical valuesPHCP (15mm)H (4mm)C (1mm)Proof strengthRp0.2MPa450480530480570600Tensile strengthRmMPa650680700700790840ElongationAb%3030–383840Impact toughnessKV1)J6060–100––HardnessHB230230230 Table 1 P = hot rolled plate. H = hot rolled coil. C = cold rolled coil and sheet. 1) Full size specimen 1 MPa = 1 N/mm2 a) Rp0.2 and Rp1.0 correspond to 0.2% offset and 1.0% offset yield strength, respectively. b) Based on L0 = 5.65 √S0 where L0 is the original gauge length and S0 the original cross-section area. Fatigue The high tensile strength of duplex steels also implies high fatigue strength. Table 5 shows the result of pulsating tensile fatigue tests (R=0.1) in air at room temperature. The fatigue strength has been evaluated at 2 million cycles and probability of rupture 50%. Since the test was made using round polished test bars from hot rolled plate, correction factors for surface roughness, notches, welds etc, are required in accordance with classical theory relating to fatigue failure. As shown by the table the fatigue strength of the duplex steels corresponds approximately to the proof strength of the material.Rp0.2RmFatigue strengthMPaMPaMPaLDX 210147869650022054977675781.4404500510360 1.4404 is equivalent to AISI 316L in these tests Standard deviation of fatigue strength, for the entire population ~ 30 MPa At high temperatures If LDX 2101 is exposed for prolonged periods to temperatures exceeding 280 °C (540 °F), the microstructure changes which results in a reduction in impact strength. This effect does not necessarily affect the behaviour of the material at the operating temperature. For example, heat exchanger tubes may be used at higher temperatures without any problems. Contact wilsonpipeline for advice.Minimum valueTemperatures50100150200300Rp0.2MPa430380350330300RmMPa630590560540540 Table 2 – Tensile properties at elevated temperatures: Physical properties Physical properties The physical properties of LDX 2101 are shown in Table 4.Temperature oC20100200300Densityx103 kg/m37.7Modules of elasticityGPa200194186180Poissons ratio0.3Linear expansion at (20->)oCx10-6/oC–13.514.014.5Thermal conductivityW/moC15161718Thermal capacityJ/kgoC500530560590Electric resistivitynΩm750800850900 Table 4 Corrosion resistance Corrosion resistance The corrosion resistance of LDX 2101 is generally good, and the grade is therefore suitable for use in a wide range of general-purpose applications and environments. The corrosion resistance is in general at least as good as that of Cr-Ni grades such as AISI 304L and in some cases as good as Cr-Ni-Mo grades such as AISI 316L. A brief description of the resistance to different types of corrosion is shown below. General corrosion General corrosion is characterised by a uniform attack on the steel surface in contact with a corrosive medium. The corrosion resistance is generally considered good if the corrosion rate is less than 0.1 mm/year. The resistance to uniform corrosion in sulphuric acid is shown in Figure 1. LDX 2101 has a better resistance than AISI 304L and in some cases performs as well as AISI 316L. Fig. 1. Isocorrosion curves, 0.1 mm/year, in sulphuric acid. Pitting and crevice corrosion The resistance to pitting and crevice corrosion increases with the content of chromium, molybdenum and nitrogen in the steel. The resistance to these types of corrosion, which are mainly caused by chloride containing environments, is good due to the grade’s high chromium and nitrogen content. The pitting corrosion resistance has been evaluated using the Avesta Cell (ASTM G 150). Figure 2 shows that the resistance is higher than that normally obtained with Cr-Ni grades such as AISI 304L and approaching that of Cr-Ni-Mo grades such as AISI 316L. Fig. 2. Critical pitting temperatures (CPT) in 1M NaCl according to ASTM G 150 using the Avesta Cell. Typical values have been given for conventional grades. Atmospheric corrosion A steel’s resistance to atmospheric corrosion is strongly linked to its resistance to uniform corrosion and localised corrosion such as pitting and crevice corrosion. Since LDX 2101 shows good resistance to these types of corrosion, it may be assumed that the resistance to atmospheric corrosion is good. Accordingly LDX 2101 should be sufficiently resistant in most environments. Stress corrosion cracking Like all duplex stainless steels, LDX 2101 shows good resistance to chloride-induced stress corrosion cracking (SCC). Many test methods are used to rank the different steel grades with respect to their resistance to SCC. One such test method is the U-bend test according to MTI Manual no. 3, in which the specimens are exposed to 3M magnesium chloride (MgCl2) solution at 100°C for 500 hours. The U-bending was performed both longitudinal and transverse the rolling direction. The results are shown below. Results from U-bend stress corrosion testing in MgCl2 4301 is equivalent to AISI 304 in this test. Intergranular corrosion Due to its duplex microstructure LDX 2101 offers verygood resistance to intergranular corrosion. LDX 2101passes intergranular corrosion tests according toEN/ISO 3651-2 method A (Strauss) and method C(Streicher). Such results are as expected for duplex steels, which are less susceptible to this kind of corrosion than austenitic stainless steels. Heat treatment Plate,sheet and coil are normally delivered in heat treated condition. If additional heat treatment is needed after further processing the following is recommended. Solution annealing 1020 -1080°C (1865 -1975°F), rapid cooling in air or water. Fabrication Hot forming Hot forming is performed in the temperature range 1100–900°C (2010-1650oF) and should be followed by solution annealing. It should, however, be observed that the strength is low at high temperatures. Cold forming Due to the high proof strength of duplex material, greater working forces than those required for austenitic steel are usually needed for cold forming. Figure 3 shows the effect of work hardening on LDX 2101. LDX 2101 is suitable for most forming operations used in stainless steel fabrication. However, due to the grade’s higher mechanical strength and lower toughness, operations such as deep drawing, stretch forming and spinning are more difficult to perform than with austenitic steel. The grade’s high strength, may give rise to a relatively high spring back. Fig. 3. Mechanical properties of LDX 2101 after cold deformation. Heat treatment LDX 2101 is solution annealed at 1020 – 1080°C (1865- 1975 oF). Rapid cooling is recommended after annealing. Welding LDX 2101 has a good weldability and can be welded using the same processes used for other duplex steels. In general the recommendations for welding duplex steels also apply for LDX 2101, however, the restrictions in arc energy are less tight than for conventional duplex steels due to the grade’s low alloy content and high nitrogen level. Suitable welding methods are manual metal-arc welding with covered electrodes or gas shielded arc welding. Welding should be undertaken within the heat input range 0.2-2.5 kJ/mm. Preheating or post-weld heat treatment is not normally necessary. Filler metals that give an austenitic-ferritic weld metal should be used in order to obtain a weld metal with corrosion resistance and mechanical properties close to the parent metal. For gas-shielded arc welding, we recommend wilsonpipeline 22.8.3.L and 23.7.L and for manual metal-arc welding the covered electrode wilsonpipeline 22.9.3.LR. These filler metals can also be used for welding LDX 2101 to carbon steels, stainless steels and nickel alloys. The covered electrode wilsonpipeline 23.12.2.LR and the wire electrode wilsonpipeline 24.13.L can also be used for dissimilar metal welding. When welding components for use in high concentrated nitric acid wilsonpipeline 23.7.L is recommended. * LDX 2101 is a trademark owned by Outokumpu OY.

Duplex 2507 Stainless Steel (UNS S32750) is a super duplex stainless steel with 25% chromium, 4% molybdenum, and 7% nickel designed for demanding applications which require exceptional strength and corrosion resistance, such as chemical process, petrochemical, and seawater equipment. The steel has excellent resistance to chloride stress corrosion cracking, high thermal conductivity, and a low coefficient of thermal expansion. The high chromium, molybdenum, and nitrogen levels provide excellent resistance to pitting, crevice, and general corrosion. Applications Oil and gas industry equipment Offshore platforms, heat exchangers, process and service water systems, fire-fighting systems, injection and ballast water systems Chemical process industries, heat exchangers, vessels, and piping Desalination plants, high pressure RO-plant and seawater piping Mechanical and structural components, high strength, corrosion-resistant parts Power industry FGD systems, utility and industrial scrubber systems, absorber towers, ducting, and piping Standards ASTM/ASME ………. A240 – UNS S32750 EURONORM………… 1.4410 – X2 Cr Ni MoN 25.7.4 AFNOR……………….. Z3 CN 25.06 Az Corrosion Resistance General Corrosion high chromium and molybdenum content of 2507 makes it extremely resistant to uniform corrosion by organic acids like formic and acetic acid. provides excellent resistance to inorganic acids, especially those containing chlorides. can be used in dilute hydrochloric acid. Pitting need not be a risk in the zone below the borderline in this figure, but crevices must be avoided. Intergranural Corrosion Low carbon content greatly lowers the risk of carbide precipitation at the grain boundaries during heat treatment. Is highly resistant to carbide-related intergranular corrosion. Stress Corrosion Cracking Duplex structure of 2507 provides excellent resistance to chloride stress corrosion cracking (SCC). Superior to 2205 in corrosion resistance and strength. 2507 is especially useful in offshore oil and gas applications and in wells with either naturally high brine levels or where brine has been injected to enhance recovery. Pitting Corrosion Different testing methods can be used to establish the pitting resistance of steels in chloride-containing solutions. Crevice Corrosion Highly resistant to crevice corrosion. Processing Hot forming 2507 should be hot worked between 1875°F and 2250°F. This should be followed by a solution anneal at 1925°F minimum and a rapid air or water quench. Cold Forming Most of the common stainless steel forming methods can be used for cold working 2507. The alloy has a higher yield strength and lower ductility than the austenitic steels so fabricators may find that higher forming forces, increased radius of bending, and increased allowance for springback are necessary. Deep drawing, stretch forming, and similar processes are more difficult to perform on 2507 than on an austenitic stainless steel. When forming requires more than 10% cold deformation, a solution anneal and quench are recommended. Heat Treatment 2507 should be solution annealed and quenched after either hot or cold forming. Solution annealing should be done at a minimum of 1925°F. Annealing should be followed immediately by a rapid air or water quench. To obtain maximum corrosion resistance, heat treated products should be pickled and rinsed. Welding 2507 possesses good weldability and can be joined to itself or other materials by shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), plasma arc welding (PAW), flux cored wire (FCW), or submerged arc welding (SAW). 2507/P100 filler metal is suggested when welding 2507 because it will produce the appropriate duplex weld structure. Preheating of 2507 is not necessary except to prevent condensation on cold metal. The interpass weld temperature should not exceed 300°F or the weld integrity can be adversely affected. The root should be shielded with argon or 90% N2/10% H2 purging gas for maximum corrosion resistance. The latter provides better corrosion resistance. Chemical Properties Typical values (Weight %)CCrNiMoNOthers0.0202574.0.27S=0.001 Mechanical Properties:Ultimate Tensile Strength, ksi116 min.0.2% Offset Yield Strength 0.2%, ksi80 min.0.1% Offset Yield Strength 0.2%, ksi91 min.Elongation in 2 inches, %15 min.Hardness Rockwell C32 max.Impact Energy, ft.-lbs.74 min. Physical PropertriesDensitylb/in30.28Modulus of Elasticitypsi x 10629Coefficient of Thermal Expansion 68-212°F/°Fx10-6/°F7.2Thermal ConductivityBtu/h ft °F8.7Heat CapacityBtu/lb/°F0.12Electrical ResistivityW-in x 10-631.5

Stainless steel grade 301 is a commonly available austenitic stainless with good corrosion resistance and elevated carbon to allow for cold working to a variety of tempers. It can be obtained in the 1/4 hard, 1/2 hard, and full hard. Specifications: S30100 Applications: High strength and excellent corrosion resistance make Type 301 Stainless Steel useful for a wide variety of applications. Typical uses include: aircraft structural parts trailer bodies utensils architectural and automotive rim roof drainage products conveyor belts variety of industrial applications. Standards: ASTM/ASME: UNS S30200 EURONORM: X 12 CrNi 17 7 DIN: 1.4310 Corrosion Resistance Good resistance in applications involving external exposure to mildly corrosive conditions at ambient temperatures. Resists outdoor, industrial, marine, and mild chemical environments susceptible to carbide precipitation during welding, which restricts its use in some applications Similar to resistance of Stainless Steel grade 304 Heat Resistance Can be exposed continuously without appreciable scaling to a max of  1600°F(871°C). Maximum exposure temperature is about 1450°F (788°C), for intermittent exposure Has an oxidation weight gain of 10mg/cm 2 in 1,000 hours, in temperatures over 1600°F (871°C). Heat Treatment Solution Treatment (Annealing) – Heat to 1010-1120°C and cool rapidly. Use low side of range for intermediate annealing. This grade cannot be hardened by thermal treatment. Cold Working hardens at high rate, creating a very high strength from cold rolling and from roll forming. more difficult to work than other austenitic stainless steels, due to its high work hardening rate. strain-hardened austenitite steel undergoes partial transformation into martensitite steel during this process. severe cold deformation can still occur, due to residual ductility. Grade 301 becomes strongly magnetic when cold rolled Welding must be annealed for maximum corrosion resistance material will lose temper in the heat affected weld zone. Welding and post weld annealing will both remove high strength induced by prior cold rolling. Spot welding is commonly used to assemble cold rolled 301 components. Chemical Properties: % Cr Ni C Si Mn P S N301Min:166––––– –Max: 18 80.15 1.002.0 0.045 0.030 0.10 Mechanical Properties: Grade/Temper Tensile Strength ksi (min.) Yield Strength 0.2% ksi (min.) Elongation -% in 50 mm (min.)301 1/41257525301 1/215011018301 Full Hard1851409 Physical Properties: Denstiy lbm/in3 Coefficient of Thermal Expansion (min/in)-°F Electrical Resistivity mW-in Thermal Conductivity BTU/hr-ft-°F Melting Range0.29at 68 – 212°Fat 68 – 932°Fat 68 – 1450°Fat 68°Fat 212°Fat 392°Fat 752°Fat 1112°Fat 1472°Fat 68 – 212°F 2550-2590°F9.210.410.928.330.733.839.443.747.69.4

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 tubes (stainless steel) for the food industry” AS1528 was revised in 2001 by key stakeholders in the Australian food manufacturing and tube industries. AS 1528 is unique, in that it covers all the associated fittings in addition to the 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 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 tube fittings. Outside Diameter Table 1. Specification requirements for standard inch series OD 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 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 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 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 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 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 A249 specifies weld bead removal. This requirement can be met from other standards. ASTM A249 does not require annealing in most food applications. 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 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 tube fittings.

Chemical Formula Fe, <0.3% C, 10.5-12.5% Cr, 0.3-1.0% Ni, <1.5% Mn, <1.0% Si, <0.4% P, <0.15% S, <0.03% N Introduction Grade 3CR12 stainless steel is a low-cost grade chromium, containing stainless steel fabricated by modifying the properties of grade 409 steel. It resists mild corrosion and wet abrasion. It was originally developed by Columbus Stainless, which designated the registered trademark “3CR12”. Other designations of this grade include UNS S40977/S41003 and 1.4003. Other designations that are equivalent to grade 3CR12 include ASME SA240 grades, ASTM A240/A240M grades and EN 10088.2. However, grade 1.4003 is also covered in EN 10028.7, which constitutes pressure-purpose stainless steels. Key Properties The following section will provide the key properties of grade 3CR12 stainless steel coil, sheet and plate, covered under Euronorm S41003, S40977, ASTM A240/A240M and EN 10088.2 1.4003. Composition The chemical compositions of various elements of grade 3CR12 stainless steels are tabulated below: Table 1. Chemical composition of grade 3CR12 stainless steelsGrade CMnSiPSCrMoNiN1.4003min.–––––10.50–0.30–S40977max.0.0301.501.000.0400.01512.50–1.000.030S41003min. max.– 0.03– 1.50– 1.00– 0.040– 0.03010.5 12.5– –– 1.50– 0.030 Mechanical Properties Given below are the mechanical properties of grade 3CR12 stainless steels: Table 3. Mechanical properties of grade 3CR12 stainless steelsGradeTensile Strength (MPa) minYield Strength 0.2% Proof Stress (MPa) minElongation (% in 50mm) minHardnessRockwell (HR) maxBrinell (HB) max1.4003450 650280 (long.) 320 (trans.)20––S4097745528018HR B88180S4100345527518HR C20223 Physical Properties The following table outlines the physical properties of grade 3CR12 stainless steels: Table 4. Physical properties of grade 3CR12 stainless steelsGradeDensity (kg/m3)Elastic Modulus (GPa)Mean Coefficient of Thermal Expansion (µm/m/°C)Thermal Conductivity (W/m.K)Specific Heat 0-100°C (J/kg.K)Electrical Resistivity (nÙ.m)0-100°C0-300°C0-700°Cat 100°Cat 500°C3CR12774020010.811.312.530.531.5480570 Grade Specification Comparison Grade specifications for 3CR12 stainless steels are given in the following table: Table 4. Grade comparisons for 3CR12 grade stainless steelsGradeUNS NoOld BritishEuronormSwedish SSJapanese JISBSEnNoName3CR12S40977––1.4003X2CrNi12–– Given above are only approximate comparisons. The table is prepared to provide a comparison of materials that are functionally similar to each other, and the specifications are not legitimate. Original specifications can be verified if exact equivalents are required. Possible Alternative Grades Suitable alternatives to grade 3CR12 stainless steels are listed in the table below: Table 5. Possible alternative grades to 3CR12 grade stainless steelsGradeWhy it might be chosen instead of 3CR12304Excellent fabrication properties and corrosion resistance.430Excellent resistance to corrosion and good appearance. It does not require welding.Galvanized steelInexpensive, fair corrosion resistance and fabrication properties.Weathering steelInexpensive, acceptable fabrication properties and corrosion resistance. Corrosion Resistance Grade 3CR12 stainless steels can be employed in applications for which aluminium, galvanized or carbon steels provide undesirable results, owing to its resistance to strong acids and alkalis, and cracking resulted from chloride stress corrosion. However, unlike grade 304, grade 3CR12 has minimal resistance to crevice and pitting corrosion in the presence of chloride. Under ambient conditions, grade 3CR12 has improved resistance to water and chloride substances, as the corrosivity of chloride contents will be mitigated by the nitrate and sulphate ions. One of the major drawbacks of grade 3CR12 is that the surface of the material is subjected to mild corrosion when exposed to any type of environment. It is due to this reason the material is limited to decorative applications. Heat Resistance Grade 3CR12 stainless steels exhibit scaling resistance between 600 and 750°C in the presence of air, and between 450 and 600°C under stress environments. The material tends to become fragile upon prolonged exposure to temperatures between 450 and 550°C. However, the material does not lose its impact resistance at this temperature range. Heat Treatment Grade 3CR12 stainless steels are annealed at temperatures ranging from 700 to 750°C, pided into 25 mm section, and each section is soaked for 1½ h. The material is then allowed to cool. Care should be taken to prevent hardening during heat treatment. The mechanical properties and corrosion resistance characteristics of this grade can be affected by quenching treatments. Once the material is annealed, processes such as pickling and passivating are performed. Welding Welding methods used for austenitic stainless steels can be applied to grade 3CR12 stainless steels. Low heat input techniques, such as GMAW (MIG) and GTAW (TIG), can be considered. During welding, grade 309 filler wire, pre-qualified by AS 1554.6, is preferred. However, grade 308L, 316L, 309Mo and 309L wires have also been employed in many cases. Any discoloration in the welded product can be removed using backing gases, or techniques such as purging and pickling. Machining Machinability of grade 3CR12 stainless steels is around 60% of that of mild steel. They have a work-hardening rate lesser than that of austenitic steels, and, hence, they do not require special machining methods. Finishes Grade 3CR12 stainless steel plates can be obtained in standard, hot-rolled annealed and pickled (HRAP) finish, and coils are available in 2B or 2D finish. Black finish can also be produced by hot-rolling the material, leaving behind a dark oxidized surface on the steel. Grade 3CR12 with black finish has a good corrosion resistance and low friction and, hence, it is suitable for different wear applications. Applications Grade 3CR12 stainless steels find application in the following: Sugar processing industries Transport equipment, such as rail wagons carrying iron ores and coal Mining and mineral processing Oven and furnaces

The common designations of austenitic grades of stainless steel, such as grades 304 and 316, include sub-grades – L and H variants used for specific applications. What “L” Grades Are and Why They Are Used The low carbon “L” grades are used for applications involving welding treatments or high temperature exposure, e.g. welding of heavy or medium sections. The low carbon content of steels prevents carbide precipitation at grain boundaries, which can cause inter-granular corrosion under corrosive operation conditions. Carbide precipitation occurs at temperatures ranging from about 450 to 850°C. Based on their applications, “L” grade steels are available in the form of pipe, plate and, most commonly, in round bars. The corrosion resistances of standard austenitic and “L” grades are identical in the absence of high temperature exposure or welding treatments. What “H” Grades Are and Why They Are Used “H” grades are high carbon stainless steel grades, having improved strength at high temperatures – generally above 500°C. These high carbon grades have high short-term and long-term creep strength. They are usually produced in the form of pipe and plate. Most commonly employed grades are grade 304H and 316H, but ASTM A240/A240M also covers high carbon versions of grade 309, 310, 321, 347 and 348. When used at temperatures of about 450-850°C, these grades are subjected to sensitization which, in turn, causes aqueous corrosion, and reduction in toughness and ductility at ambient temperatures. What the Differences Are 304 and 304L Grades 304 and 304L have the same composition limits for all components except carbon. However, neither grade 304 nor grade 304L is specified to have minimum carbon content. 304 and 304H Grade 304H is a high carbon version of grade 304, and it has the same composition specification as that of standard grade 304. Grade 304H does not have the 0.10% nitrogen maximum limit which is applicable to both “L” and standard grades. All austenitic “H” grades should have a grain size of ASTM No 7. 316, 316L and 316H The three grades 316, 316L and 316H are the major counterparts of grade 304. Only the percentage of carbon contents differentiates these grades. The following table provides the carbon content of the alternatives covered under ASTM A240/A240M: Table 1. Stainless steel carbon contentsGradeUNS NumberSpecified Carbon Content (%)304S304000.08 max304LS304030.030 max304HS304090.04-0.10316S316000.08 max316LS316030.030 max316HS316090.04-0.10 NOTE: Specifications for some other products, particularly stainless steel tube and stainless steel pipe, have a limit of 0.035% or 0.040% maximum for 304L and 316L, but are otherwise the same. Property Specifications The table below specifies the differences in mechanical properties of various grades: Table 2. Stainless steel property specificationsGradeUNSTensile Strength (MPa) minYield Strength (MPa) minElongation (%) minBrinell Hardness (HB) maxRockwell Hardness (HRB)max304S304005152054020192304LS304034851704020192304HS304095152054020192316S316005152054021795316LS316034851704021795316HS316095152054021795 In practice, steel mills generally ensure that the “L” grade heats meet the strength requirements of the standard grades. Dimensional Tolerance Differences There are no dimensional or other differences between standard, “L” and “H” grades. Pressure Vessels Pressure vessel codes, such as AS1210, and pressure piping codes, such as AS4041, provide allowable working pressures for each of the stainless steel grades at high temperatures. These codes provide high-pressure ratings for standard stainless steel grades when compared to that of “L” grades at any temperature. The codes avoid utilization of “L” grade steels at temperature of 425 or 525°C. The codes consist of a clause stating that standard grades, which contain at least 0.04% carbon, must be used at temperatures above 550°C. Therefore, grades 304 or 316, having 0.02% carbon, are not allowed to be used at high temperatures. The pressure vessel codes provide the same allowable pressure rating for “H” grades. Alternative Grade Usage It is possible to use a product labelled as a standard grade instead of “L” or “H” grade, or vice versa, owing to the availability issues. This substitution can be made under the following conditions: High Temperature Strength Requirements “L” grades can be used as standard grades as long as high temperature strength is not required, and the mechanical properties conform to the standard grade requirements. “L” grades nearly always comply with the standard grade requirements, but this must be investigated on each occasion. Tested Carbon Content – L Grades Standard grades can be used as “L” grades if their carbon content meets the “L” grade limits of 0.030 or 0.035% maximum. Tested Carbon Content – H Grades Standard grades are often used instead of “H” grades as their carbon contents meet the “H” limits of 0.04 to 0.10%. Additional testing may be required to satisfy the grain size requirement. “H” grades having a maximum 0.10% of nitrogen and 0.08% of carbon are used as standard grades. Dual Certification It is very common for steel mills to supply “L” heats when standard grades have been ordered. In fact, some of the product and test certificates are marked “304/304L”. In some cases the product is marked only as standard, or “L”. The details provided on the mill test certificate will show if the alternative grades comply with the standard. The requirement of an “H” grade for any high temperature application must be specified during the time of order. The required high carbon steel will be supplied, based on availability. The product and its test certificate will confirm grade compliance.

wilsonpipeline are super duplex stainless steel suppliers in plate, sheet, and bar forms to a range of industries. The stock is held in our warehouse where we also house several cutting and profiling capabilities, this alongside our ability to distribute globally makes wilsonpipeline a great supplier of duplex alloys. There are a number of stainless steel super duplex characteristics such as: High resistance to stress corrosion cracking and chloramines at high temperature Good fatigue and mechanical strength High inherent corrosion resistance, particularly in acids and pitting Super Duplex Stainless Steel GradesGradeUNSASTM/ASMEWerkstoffDuplexS31803A240 / F511.4462Super DuplexS32750A240 / F531.4410Super DuplexS32760A240 / F551.4501Lean DuplexS32304A2401.43626 MolyS31254A240 / F441.4547

Stainless steel grade LDX 2404® is a lean duplex stainless steel containing molybdenum. The new duplex grade LDX 2404® has been designed with a property profile to fill the gap between the existing Duplex steel grades 2304 and 2205. It is also specially designed as a replacement of grade 304/304L in several applications. LDX 2404® steel has high resistance to uniform corrosion, to pitting and crevice corrosion, and to stress corrosion cracking. It has excellent mechanical strength, good abrasion and erosion resistance, good fatigue resistance, and good weldability. High energy absorption and low thermal expansion are two other characteristics of this material. The following datasheet provides an overview of stainless steel grade LDX 2404®. Chemical Composition The chemical composition of stainless steel grade LDX 2404® is outlined in the following table.ElementContent (%)Iron, FeBalanceChromium, Cr24Nickel, Ni3.6Manganese, Mn3Molybdenum, Mo1.6Nitrogen, N0.27Carbon, C0.02 Mechanical Properties The mechanical properties of stainless steel grade LDX 2404® are displayed in the following table.PropertiesMetricImperialTensile strength (cold rolled plate and sheet)680 MPa98625 psiModulus of elasticity (68°F/ 106)0.19994 GPa29 ksiPoisson’s ratio0.30.3Elongation at break (In 2″, 50% cold worked)25%25% Other Designations Equivalent material to stainless steel grade LDX 2404® is EN 1.4662. Manufacturing Process Stainless steel grade LDX 2404® can be hot formed in the temperature range 900-1120°C (1652-2048°F), which should be followed by solution annealing to regain the original properties. The mechanical strength of this steel tends to be low at these high temperatures. Welding can be easily performed using traditional methods. Likewise cold forming is also suitable for this steel. To perform heat treatment, LDX 2404® steel should be solution annealed at 1000-1120°C (1832-2048°F). Rapid cooling should be performed after annealing to regain the original properties. Applications The applications of stainless steel grade LDX 2404® are as follows: Energy sector Oil and gas sector Storage tanks Pulp and paper Piping systems Process industry Structural components Boilers and water heaters Architectural applications Water treatment and desalination