UR 2205 with 22% Cr and 3% Mo additions, performs much better than 316L grade in almost all corrosive media.

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1 Industeel URANUS 225 A 22Cr duplex URANUS 225 is a nitrogen alloyed (>.15%) austenitic-ferritic stainless steel with improved structure stability and high general, localised and stress corrosion resistance. with 22% Cr and % Mo additions, performs much better than 16L grade in almost all corrosive media. The yield strength is about twice that of austenitic stainless steels. This allows the designer to save weight and makes the alloy more cost competitive compared to 16L grade. Typical operation temperatures are - C/+28 C (-58 F/+56 F). Lower temperatures could be considered, but require additional precautions, in particular for welded structures. is a multi-purpose material which can be used in various corrosive media. Typical applications are Pulp and Paper, Oil and Gas, Pollution control equipments, Chemical industry and Chemical tankers. Standard EURONORM : X2 Cr Ni Mo N ASTM : A24 - UNS S18 Chemical analysis Typical values (Weight %) C Cr Ni Mo N Mo content is optimised in the % range Mechanical properties Tensile properties - Minimum values PREN = [Cr %] +. [Mo %] + 16 [N %] > or 4 C R p.2 MPa R p 1. MPa R m MPa F YS.2% KSI YS 1.% KSI UTS KSI A/El% For solution annealed condition and plate thickness mm (2 ). grade should not be used over 28 C (5 F) for extended periods of time. URANUS 225 Rev. 4-22/1/21 issue - page 1

2 Impact strength (KV minimum values) Temp. - C -2 C +2 C -6 F F +7 F Single 75J 9J 12J 54ft.lbs 65ft.lbs 87ft.lbs Average (5) 9J 12J 1J 65ft.lbs 87ft.lbs 19ft.lbs Hardness values - Typical values Average (5) HV HB: HRC: 15-2 Physical properties Density: 7,85kg/dm Temperature interval ( C) Thermal expansion x1-6 K -1 T ( C) Resistivity (µω cm) Thermal conductivity (W m -1 K -1 ) Specific heat (J kg- 1 K -1 ) Young modulus E (GPa) Shear modulus G (GPa) Density:.282Lb/in Temperature interval ( F) Thermal expansion x1-6 F -1 T ( F) Resistivity (µω.in) Thermal conductivity (Btu.hr -1.ft -1. F -1 ) Specific heat x1 6 (Btu.lb -1. F -1 ) Young modulus E x1 6 (psi) Shear modulus G x1 6 (psi) Structures URANUS 225 is a duplex stainless steel; its chemical composition is optimized in order to present, after a solution annealing treatment at C ( F) followed by water quenching, a nearly % α /% γ microstructure. Heat treatments performed at 11 C (21 F) and higher may result in an increase of the ferrite content. Typical TTP-diagram (temperature time precipitation) shows the two-phase transformation areas. At high temperature : 1-6 C ( F), the α phase may transform in σ, χ,... intermetallic phases which makes the alloy brittle. At lower temperature (- C F) the α phase transforms in α' resulting in a hardening of the structure after several hours holding time. URANUS 225 Rev. 4-22/1/21 issue - page 2

3 c σ, χ, Cr2N γ2, M2C6 F minutes 1 2 hours α' TTP DIAGRAM of duplex stainless steel Corrosion resistance General corrosion resistance a) Sulfuric and phosphoric acids % H 2 SO 4 + 2ppm Cl - Industrial solution 54%P 2 5 2% - H 2 SO 4 +.2%HF+1.6%H 2 SIF 6 Industrial solution General corrosion resistance properties of alloy are generally much better than austenitic 16L and 17LN alloys. alloy is now used extensively in newly designed chemical tankers. b) Caustic media (pulp and paper) and organic acids mm/year 1 1 g/l Cl - mm/year L 16L. Heat transfert Solution at 14 C (285 F) Sample at 8 C (175 F) Pulp & paper caustic solution with sulphur compounds 16 Acetic 1% Boiling Formic % Boiling acid solutions Oxalic 1% Boiling Acetic % Formic % Boiling General corrosion resistance in organic solutions or caustic solutions is improved by the use of instead of 4 or 16 L grades. is extensively used in chemical industries (organic and inorganic) and in the pulp and paper industry. URANUS 225 Rev. 4-22/1/21 issue - page

4 Localised corrosion resistance a) Pitting corrosion C F L Cl - % Sensitivity to pitting corrosion Effects of temperature and chloride content 8 C L Guaranteed 16L Ask Us S18 ASTM G48A Test results 1%Fe Cl 6H 2 O F The high chromium (22%) and molybdenum (%) combined with.16% nitrogen all contribute to the high pitting resistance of. It outperforms 4 and 16L, even in very oxidizing and acidic solutions. b) Crevice corrosion resistance 125 µa/cm² L 4 17 LNM.5 1 1,5 2 ph 5 C L Guaranteed 16L Ask us F S18 Depassivation conditions of several stainless steels Solution: g/l NaCl 2 C ASTM G78 - Crevice 1% FeCl 6H 2 O solution The improved crevice corrosion resistance of explains its use in chloride/fluoride processes containing deposits. Typical applications are Pulp and Paper industry, Pollution Control equipments, On/Offshore applications. Stress corrosion cracking resistance C F 2 48 Neutral aerated aqueous solution / Cl% The duplex microstructure is known to improve the stress corrosion cracking resistance of stainless steels. This is the case in neutral aerated aqueous solutions containing chlorides and in sour gas conditions in the oil and gas industry. is used extensively for welded pipe. URANUS 225 Rev. 4-22/1/21 issue - page 4

5 Corrosion fatigue resistance Duplex stainless steels combine high mechanical and corrosion resistance. The fatigue corrosion data presented are very attractive results since after 1 7 cycles, fatigue limit remains at least twice that of 16 austenitic stainless steels. Synthetic sea water solution (smooth samples) MPa L 2.5 Mo 16 ksi Cycle to rupture Processing Hot forming Hot forming should be carried out in a temperature range of 9/11 C (17/21 F) after the piece has been uniformly heated. At temperatures lower than 9 C (17 F), the alloy is very prone to intermetallic phase precipitation, such as sigma phase. This affects the toughness and corrosion resistance properties of. A final full annealing heat treatment (14-18 C / F) followed by rapid quench, is required to restore phase balance, mechanical and corrosion resistance properties. Special precautions must be taken during heat treatment to avoid deformation. Cold forming can be cold formed without any problem using equipment suited to work stainless steel. The duplex UR 225 alloy requires more power than austenitic stainless steels due to its higher mechanical properties and work hardening (which is lower than for austenitic steels). Cold working ratios exceeding 2% require an intermediate full annealing heat treatment (14/18 C - 19/1975 F). Such heat treatment is also recommended after cold forming of more than 1 % in order to restore its properties MPa Tensile strength Yield strength Elongation (E%) KSI E% Pickling Pickling solutions or pastes acceptable for alloy 16 L may be used. The pickling time required is at least twice that of 16L. A slight increase of the temperature of the pickling bath reduces the pickling time. Typical pickling conditions are (1 % HNO - 2% HF) 6 C (14 F). Passivation decontamination treatments may be performed with a 1-25% nitric acid solution. URANUS 225 Rev. 4-22/1/21 issue - page 5

6 Machining Machining is another example of a fabrication process where the techniques employed (eg. tools and lubricants) for are very similar to those used for conventional stainless steels). Machining characteristics of are better than those of 16L. Operation Tool Lubrication High speed steel Cutting oil Turning Carbide Dry or cutting oil Depth of cut (mm) (inch) Feed (mm) (inch) CONDITIONS SPEED (m/min) SPEED (feet/min) 18/8 18/12 Mo UR Blade width Feed SPEED (m/min (feet/min) Parting off High speed steel Cutting oil Drill dia. Feed SPEED (m/min) (feet/min) Drilling High speed steel Cutting oil Milling profiling High speed steel Cutting oil Feed SPEED (m/min) (feet/min) Welding - is easily welded by the following processes : - TIG welding, both manual and automatic, - Plasma welding, - MIG welding, - SMAW, - SAW - FCAW - Austenitic-ferritic structure of steel (ferrite primary solidification) limits hot cracking risks in the HAZ. - Special care must be taken in controlling the ferrite content of the weld deposit which is usually between 25 and 6 % ; a lower ferrite content will be recommended (2-4 % of α, for some welding procedures) i.e. for SMAW, SAW and FCAW. - Chemical composition has to be adapted to stabilize austenite (generally, nickel or nitrogen overalloyings compared to the base metal). Cr and Mo overalloyed filler metals are also recommended in order to increase the corrosion resistance properties of welded structures. URANUS 225 Rev. 4-22/1/21 issue - page 6

7 - As for austenitic grades, no preheat is necessary prior to welding, - The heat input must be controlled (about 1 to 25 kj/cm is generally counselled) - Consult our technical staff for more accurate information if needed. Optimum heat input is related to plate thicknesses. -Interpass temperature must be limited to 1 C (2 F), preferably 12 C (248 F). - Post weld heat treatment is normally not necessary. In some cases, it might be needed to obtain a low ferrite content when welding without filler metal. Heat treatment will be realised at a sufficient temperature to avoid phase transformation. - Usual precautions including cleaning and degreasing of weld area, protection against weld spatters must be taken to ensure corrosion resistance of the finished product. - Careful final mechanical or/and chemical cleaning of the weld is strongly recommended. Plasma + TIG welding: Typically used for thicknesses of 5 to 12 mm. If no filler metal is used for the plasma pass, Ar + (2-)% N 2 will be used as shielding gas. Ferrite content will be between and 6 %. Complementary TIG welding will also be realised with a duplex or superduplex wire. The ferrite content will also be kept between and 6 %. Nitrogen additions (2-%) in the protective gas improve the corrosion behaviour and stabilize the microstructure. Technical is available for special cases. Contamination of the shielding gas by hydrogen must be avoided. Manual arc welding: A standard duplex or super-duplex electrode will be used. The ferrite content is between 2 and 4%. Avoid hydrogen pick up (moisture, hydrogen containing gases...) which can result in cold cracking. For further information, please contact us (choice of the electrode depending on the application). Submerged arc welding: This process can be used for single pass or multipass welds for high thicknesses (>1 mm) or to complete a plasma pass. The filler metal is a duplex wire, basic fluxes should be preferred. Ferrite content will be controlled between 2 and 4 % in order to avoid cold cracking risks; Use only well dryed fluxes to avoid hydrogen uptake. Design is particularly cost effective when its high mechanical strength of the alloy are taken into account to design vessels. Allowable design stress values: ASME boiler and pressure vessel codes. Section VIII - Division 1, Stress, MPa - KSI Grade -/4 C (-2/1 F) 25 C (4 F) 26 C ( F) MPa KSI MPa KSI MPa KSI 16L L These higher design stress values allow the fabricator to reduce the weight of the equipment which, combined with the high corrosion resistance properties, provide additional cost savings. URANUS 225 Rev. 4-22/1/21 issue - page 7

8 Applications - Oil and Gas industry including sour gas applications - Pulp and Paper industry (digesters...) - Chemical industry (reactor vessels...) - Acetic acid distillation towers - Phosphoric acid plants (reactors...) - Sulphuric acid processes (hydrometallurgy...) - Pollution control equipments - Trucks, lorries - Chemical tankers Size range Hot rolled plates N 1 (ASTM)/ N 1D (EN) Width (mm) <12 Quarto plates : other sizes are available on request, consult Industeel. 225 clad plates,consult Industeel Creusot. Thickness (mm) Coils or CMP (ArcelorMittal Stainless Europe) Quarto plates (Industeel) Cold rolled plates Width (mm) ArcelorMittal Stainless Europe : Cold rolled 2B Thickness (mm) Cold rolled 2E For any information Industeel Creusot 56 rue Clemenceau F-7121 Le Creusot Cedex Tel Fax Industeel Belgium 266 rue de Chatelet B-6 Charleroi Tel Fax Stainless Europe Head office 1, 5 rue Luigi Cherubini 9212 La Plaine Saint-Denis Cedex Tel Fax This technical data and information represent our best knowledge at the time of printing. However, it may be subject to some slight variations due to our ongoing research programme on corrosion resistant grades. We therefore suggest that information be verified at time of enquiry or order. Furthermore, in service, real conditions are specific for each application. The data presented here is only for the purpose of description, and may only be considered as guarantees when our company has given written formal approval. URANUS 225 Rev. 4-22/1/21 issue - page 8