Austenitic, Cr-Ni alloyed stainless steel

Standard Cr-NiStainless SteelsCharacteristic properties• All-purpose grades• Good corrosion resistance• Excellent formability• Excellent weldability• Excellent impact strength• Supplied with a range of functional and aesthetic surface finishesChemical compositionThe chemical composition of specific steel grades may vary slightly between different product standards.The required standard will be fully met as specified on the order.Steel gradesOutokumpu EN ASTM4318 1.4318 301LN4301 1.4301 3044307 1.4307 304L4311 1.4311 304LN4541 1.4541 3214306 1.4306 304LAvestaPolarit International Typical composition, % National steel designations, steel name steel no. superseded by EN EN ASTM C N Cr Ni Mo Others BS DIN NF SS 4318 1.4318 301LN 0.02 0.14 17.7 6.5 – – – – Z3 CN 18-07 Az – 4301 1.4301 304 0.04 – 18.1 8.3 – – 304S31 1,4301 Z7 CN 18-09 2333 4307 1.4307 304L 0.02 – 18.1 8.3 – – 304S11 – Z3 CN 18-10 2352 4311 1.4311 304LN 0.02 0.14 18.5 10.5 – – 304S61 1.4311 Z3 CN 18-10 Az 2371 4541 1.4541 321 0,04 – 17.3 9.1 – Ti 321S31 1.4541 Z6 CNT 18-10 2337 4306 1.4306 304L 0.02 – 18.2 10.1 – – 304S11 1.4306 Z3 CN 18-10 2352 4401 1.4401 316 0.04 – 17.2 10.2 2.1 – S316S31 1.4401 Z7 CND 17-11-02 2347 4436 1.4436 316 0.04 – 16.9 10.7 2.6 – 316S33 1.4436 Z7 CND 18-12-03 2343 904L 1.4539 904L 0.01 – 20 25 4.3 1.5 Cu 904S13 1.4539 Z2 NCDU 25-20 2562 LDX 2101® 1.4162 S32101 0.03 0.22 21.5 1.5 0.3 5 Mn – – – – 2304 1.4362 S32304 0.02 0.10 23 4.8 0.3 – – 1.4362 Z3 CN 23-04 Az 2327 2205 1.4462 S32205* 0.02 0.17 22 5.7 3.1 – 318S13 1.4462 Z3 CND 22-05 Az 2377Chemical composition Table 1General characteristicsThis group of steels includes the most widely used stainless chromium-nickel steels. They are general-purpose grades with good resistance to atmospheric corrosion and to many organic and inorganic chemicals.They are suitable for processing, storing and transporting foodstuffs and beverages. This, together with their good formability and that they are supplied with a wide range of functional and aesthetic surfaces, makes them suitable for use in a variety of applications.Non-titanium-stabilised grades generally have a better surface finish than titanium-stabilised grades.These grades are non-magnetic in the annealed condition but may become slightly magnetic as a result of phase transfor-mation to martensite or ferrite after cold working and weld-ing respectively. Some of these grades have higher structural stability than others. This is utilized for grade 4318, which is easily partly transformed to martensite during cold working operations, resulting in an increase of strenght and hardness of the material. On the other hand, if transformations are undesirable grade 4306, which has a slightly higher nickel content making transformations more unlikely, is preferable.* Also available as S31803Outokumpu Stainless2 Standard Cr-Ni Stainless SteelsMechanical properties. Hot rolled plate/cold rolled strip and sheet, minimum values at 20°C Table 2Mechanical propertiesOutokumpu Stainless uses the European Standard EN10088 where applicable. The permitted design values-may vary between product forms, see the relevant specifi-cation for the correct value.Steel grade Proof strength Tensile strength Elongation Impact value Rp0.2 Rp1.0 Rm A5 KV MPa MPa MPa % J4318 330/350 370/380 630/650 35/40 604307 200/220 240/250 500/520 45/45 604301 210/230 250/260 520/540 45/45 604311 270/290 310/320 550/550 40/40 604541 200/220 240/250 500/520 40/40 604306 200/220 240/250 500/520 45/45 60The values in Table 2 refer to hot rolled plate/cold rolled strip and sheet. For hot rolled strip, the proof strength cor-responds to that of hot rolled plate, and thetensile strength and elongation to that of cold rolled strip.Tensile properties at elevated temperatures.Proof strength Rp0.2, MPa, minimum values Table 4aSteel grade Temperature, °C 100 200 300 400 5004318 265 185 170 – –4307 147 118 100 89 814301 157 127 110 98 924311 205 157 136 125 1194541 176 157 136 125 1194306 147 118 100 89 81Tensile properties at elevated temperatures.Proof strength Rp1.0, MPa, minimum values Table 4bMechanical properties at low temperatures.Proof strength Rm, MPa, minimum values Table 5Steel grade Temp Rp0.2 Rp1.0 Rm A5 °C MPa MPa MPa %4307 -80 220 290 830 354301 -80 270 350 860 354311 -80 350 420 850 404541 -80 200 240 855 354307 -196 300 400 1200 304301 -196 300 400 1250 304311 -196 550 650 1250 354541 -196 200 240 1200 30Values from EN 10028-7 (Annex F-informative).Tensile properties at elevated temperatures.Proof strength Rm, MPa, minimum values Table 4cSteel grade Temperature, °C 100 200 300 400 5004404 530 460 440 – –4307 410 360 340 – –4301 450 400 380 380 3604311 490 430 410 – –4541 440 390 375 375 3604306 410 360 340 – –Steel grade Temperature, °C 100 200 300 400 5004318 300 215 200 – –4307 181 147 127 116 1094301 191 157 135 125 1204311 240 187 167 156 1494541 208 186 167 156 1494306 181 147 127 116 109Mechanical properties. Hot rolled plate/cold rolled strip and sheet, typical values at 20°C Table 3Steel grade Proof strength Tensile strength Elongation Hardness Rp0.2 Rp1.0 Rm A5 HB MPa MPa MPa % 43184301 290/300 330/330 600/600 55/55 165/1754307 280/300 320/330 580/600 55/55 165/1754311 320/ 360/ 640/ 55/ –/–4541 250/270 290/310 570/590 55/55 165/1604306 280/280 320/310 580/580 55/55 165/155344364301Temperature, °CC3H4(OH)(COOH)3 weight %2000 20 40 60 80 1006080100120140120Temperature, °C01008060402010 20 30 40 50 60 70 80 90 100H2SO4%43014436904L44364301Standard Cr-Ni Stainless SteelsPhysical propertiesThe physical properties are the same for all of these steel grades.Data according to EN 10088. Physical properties, typical values at 20°C Table 6Density kg/dm3 7.9Modulus of elasticity GPa 200Poissons ratio 0.3Thermal conductivity W/m°C 15Heat capacity J/kg°C 500Electrical resistivity µOm 0.73Physical properties at elevated temperatures.Linear expansion (RT?T) x 10-6/°C Table 7aSteel grade Temperature, °C 100 200 300 400 500All grades 16.0 16.5 17.0 17.5 18.0Physical properties at elevated temperatures.Modulus of elasticity, GPa Table 7bSteel grade Temperature, °C 100 200 300 400 500All grades 194 186 179 172 165Corrosion ResistanceThe Cr-Ni standard stainless steels have a versatile corrosion resistance and are suitable for a wide range of general-pur-pose applications. A brief description of their resistance to different types of corrosion follows below. For a more detailed description of their corrosion resistance properties in different environments, please refer to our Corrosion Handbook. Uniform corrosionUniform corrosion is characterised by a uniform attack on the steel surface that has come into contact with a corrosive medium. The corrosion resistance is generally considered good if the corrosion rate is less than 0.1 mm/year. This group of Cr-Ni grades have a good resistance in many organic and inorganic chemicals. Examples of isocorrosion diagrams are shown in figures 1 and 2. Fig. 1. Isocorrosion diagram for 4301, 4436 and 904L in stagnantsulphuric acid. The curves repre-sent a corrosion rate of 0.1 mm/y. The dashed line represents the boiling point.Atmospheric corrosionThe resistance to atmospheric corrosion provided by these grades is good. From an appearance point of view, these gra-des are usually sufficiently resistant in most environments, with the exception of marine and coastal, where 4401 or higher alloyed grades should be used.In heavy industrial or polluted areas, washing is important to prevent the formation of deposits, which can cause cor-rosion.Fig. 2. Isocorrosion diagram, 0.1 mm/year, for stain-less steels in citric acid. The dashed line repre-sents the boiling point, the dot-dashed line solubility.MPaCold working, %8007006005004003002001000 010 10020 20030 30040506070A5% HB800 5 10 15 20 25Temperature, °CCl_ ppmp=pitting, solid line c=crevice corrosion, dashed line2030405060708010 100 10004404 c 4307 p 4404 p4307 c4 Standard Cr-Ni Stainless SteelsPitting and crevice corrosionThese corrosion forms typically occur in acidic, neutral or slightly alkaline chloride solutions. The resistance to pitting and crevice corrosion provided by these grades is moderate compared to that offered by other, more highly alloyed stainless steels. They may also be sensitive to these types of corrosion in media with a low chloride content. For bet-ter resistance, molybdenum alloyed grades such as 4401 are recommended. The corrosion resistance can be enhanced by increasing the content of chromium, molybdenum and nitrogen.Figure 3 shows up to which approximate temperatures stan-dard stainless steel can be used in oxygen-saturated solutions of varying chloride content. There is an additional risk of stress corrosion cracking at temperatures above 50°C. Fig. 3. Risk of pitting and crevice corrosion on con-ventional stainless steel in water of different chloride content or temperature.Stress corrosion crackingThis group of austenitic standard Cr-Ni grades are susceptible to stress corrosion cracking (SCC). Critical servi-ce conditions, i.e. applications subjected to combinations of tensile stresses, temperatures above about 50°C and solutions containing chlorides, should be avoided.For applications demanding high resistance to SCC, the duplex grades 2205, 2304 and LDX 201 are more suitable.Stress corrosion cracking may also occur in hot alkaline solu-tions (above 110°C).Intergranular corrosionIntergranular corrosion is not a common problem for modern stainless steels since the carbon content is generally kept at a low level. Operations that increase the risk for intergranular corro-sion are welding of heavy gauges, heat treatment operations within the critical temperature interval (550 – 850°C) and slow cooling after heat treatment or hot forming. Ti-stabili-sed steels and steels with low carbon content (0.02%) have better resistance towards intergranular corrosion after such Heat tratmentAnnealingQuench annealing should be performed at 1000 – 1100°C and followed by rapid cooling in water or air. For Ti-sta-bilised grades, annealing temperatures above 1070°C may impair the resistance to intergranular corrosion.Ti-stabilised grades may also be given a stabilising treatment at lower temperatures. However, temperatures below 980°C should only be used after due consideration of the intended service environment.Fig. 4. 4301 work-hardening at cold workingoperation conditions.FabricationHot formingHot working can be carried out in the 850 – 1150°C range. For maximum corrosion resistance, forgings should be anne-aled at 1050°C and rapidly cooled in air or water after hot working operations.Cold formingThese grades can be readily formed and fabricated by a full range of cold working operations. They can be used in heading, drawing and bending. Any cold working operations will increase the strength and hardness of the material and may leave it slightly magnetic (see Figure 4). Work harde-ning is aaccentuated by the partial transformation of the austenite phase of the material to hard martensite. At lower contents of alloying elements, the stability of the austenite decreases; more martensite is formed during cold working, which may make the cold working operation more difficult and lead to embrittlement of the product. In many cases, a grade with a more stable austenitic structure is preferable for cold working purposes, e.g. 4306. For more information on deep drawing, contact Avesta Research Centre.5WeldingThese grades can be readily welded by a full range of con-ventional welding methods such as:• Shielded metal arc welding (SMAW)• Gas tungsten arc welding, TIG (GTAW)• Gas metal arc welding, MIG (GMAW)• Flux-cored arc welding (FCAW)• Plasma arc welding (PAW)• Submerged arc welding (SAW)The following welding filler metals from Avesta Welding are recommended:Molybdenum containing austenitic stainless steel fil-ler metals may also be suitable for some applications. For further information, contact Avesta Welding or seewww.avestawelding.comStandard Cr-Ni Stainless SteelsMachinability index1.41.210.80.60.40.20 4436 4301 4541 4436 PRODEC®Machining withcemented carbide tools high speed steel toolsFig. 5. Relative machinability for som stainless steel grades Table 8Steelgrade Filler4318 308L/MVR4301 308L/MVR4307 308L/MVR4311 308L/MVR4541 347L/MVNb, 308L/MVR4306 308L/MVRIn applications where high residual stresses cannot be accep-ted, stress relief treatment may be necessary. This can be per-formed by annealing as outlined above, but may also be per-formed at lower temperatures. Please contact Outokumpu Stainless for further information.HardeningThese grades cannot be hardened by heat treatment.However, they can be hardened by cold working.MachiningThese austenitic grades are more difficult to machine than ordinary carbon steels but are still comparatively easy to machine compared to more highly alloyed stainless grades. Unless modified for improved machinability, they require higher cutting forces than carbon steels, show resistance to chip breaking and a high tendency to built-up edge forma-tion. The best machining results are obtained by using high-power equipment, sharp tooling and a rigid set-up.The machinability of these grades in relation to other stain-less steels is indicated by the machinability index given in Figure 5. This index, which rises with increased machinabi-lity, is based on a compounded evaluation of test data from several different machining operations. It gives an indication of the machinability of different stainless steel grades compa-red to that of grade 4436. It should be noted that it does not describe the relative difficulty of machining with cemented carbide and high speed steel tools. Nitrogen alloyed stainless steels are more difficult to machine.Better machinability performance is given by PRODEC ver-sions, which have been modified for improved machinability. PRODEC is available as hot rolled plate and bar in 4301 and 4307.For more information, contact Avesta Research Centre.Products• Hot rolled plate, sheet and strip• Cold rolled plate, sheet and coil• Cold rolled narrow strip• Welded tube and pipe• Bar• Rod• Billet• Welding consumables6 Standard Cr-Ni Stainless Steels1197EN-GB:3. Centrum Tryck AB, Avesta, Sweden. March 2006. www.outokumpu.com/stainlessOutokumpu Stainless AB, Avesta Research CentreBox 74, SE-774 22 Avesta, Sweden Tel. +46 (0)226 810 00, Fax +46 (0)226 810 77Outokumpu is a dynamic metals and technology group with a clear target to become the number one in stainless steel. Customer in a wide range of industries use our metal products, technologies and services worldwide. We are dedicated to helping our customers gain competitive advantage. We call this promise the Outokumpu factor.EN 10088-1 Stainless steels – List of stainless steels (Not for ordering)EN 10088-2 Stainless steels – Sheet/plate and strip for general purposesEN 10088-3 Stainless steels – Semi-finished products, bars, rods, sections for general purposesEN 10028-7 Flat products for pressure purposes – Stainless steelsEN 10272 Stainless steel bars for pressure purposesASTM A480 General requirements for flat-rolled stainless and heat resisting steelASTM A959 Harmonized standard grade compositions for wrought stainlessASTM A240/ASME SA-240 Heat-resisting Cr and Cr-Ni stainless steel plate, sheet and strip for pressure vesselsASTM A666/ASME SA-666 Austenitic stainless steel sheet, strip, plate, bar for structural and architectural applicationsMaterial Standards Table 9Information given in this brochure may be subject to alterations without notice. Care has been taken to ensure that the contents of this publication are accurate but Outokumpu Stainless and its a?liated companies to not accept responsibility for errors or for information which is found to be misleading. Suggestions for or descriptions of the end use or application of products or methods of working are for information only and Outokumpu Stainless and its a?liated companies accept no liability in respect thereof. Before using products supplied or manufactured by the company the costumer should satisfy himself of their suitability.