Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Flange

1,We Manufacturing processes are primarily classified into four types: 1:Forging, 2:Casting, 3:Cutting, 4:Rolling. 2,We can manufacture in accordance with these standards. Standards: GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards). Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others. The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160. The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500. Flange Classification 1. **According to Chemical Industry Standards:** Flanges are classified as follows: Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)). 2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows: Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation). 3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows: Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange. 4. **According to Connection Method/Type:** Flanges are classified as follows: Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc. 5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges. 6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges. A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts." -:- For detailed product information, please contact sales. -: Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Flange Product Information -:- For detailed product information, please contact sales. -: Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Flange Synonyms -:- For detailed product information, please contact sales. -:

Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Name:** Outokumpu 254 SMO® (UNS S31254 / 1.4547) High-Performance Austenitic Stainless Steel **Classification:** Super Austenitic Stainless Steel with Extreme Chloride Resistance --- ### **1. Overview** Outokumpu 254 SMO® is a **premium super austenitic stainless steel** specifically engineered to deliver exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in the most aggressive chloride-containing environments. It represents the pinnacle of stainless steel performance, bridging the gap between standard austenitic grades and nickel-based alloys. With an exceptionally high **Pitting Resistance Equivalent Number (PREN >43)**, 254 SMO® is the benchmark material for applications where conventional stainless steels fail, particularly in seawater, chemical processing, and pollution control. The trademark **SMO®** signifies its high Molybdenum content and superior performance. ### **2. Chemical Composition (Weight %, typical)** The composition is meticulously balanced to maximize chloride ion resistance while maintaining structural integrity. | Element | Minimum (%) | Typical (%) | Maximum (%) | Notes | |---------|------------|------------|------------|-------| | **Carbon (C)** | - | 0.010 | 0.020 | Extremely low carbon prevents sensitization, ensuring excellent weldability and intergranular corrosion resistance. | | **Chromium (Cr)** | 19.5 | 20.0 | 20.5 | Provides fundamental passivity and resistance to oxidizing media. | | **Nickel (Ni)** | 17.5 | 18.0 | 18.5 | Stabilizes the austenitic phase and provides essential resistance to stress corrosion cracking (SCC). | | **Molybdenum (Mo)** | 6.0 | 6.1 | 6.5 | **The defining element.** This very high molybdenum content is the primary contributor to its unparalleled resistance to localized corrosion in chlorides. | | **Copper (Cu)** | 0.50 | 0.70 | 1.00 | Enhances resistance to reducing acids, particularly sulfuric acid. | | **Nitrogen (N)** | 0.18 | 0.20 | 0.22 | **Critical additive.** Significantly increases pitting resistance and provides solid solution strengthening, elevating yield strength. | | **Manganese (Mn)** | - | 0.5 | 1.00 | Austenite stabilizer. | | **Silicon (Si)** | - | 0.30 | 0.40 | - | | **Phosphorus (P)** | - | 0.020 | 0.030 | - | | **Sulfur (S)** | - | 0.005 | 0.010 | Kept very low for optimal corrosion resistance. | | **Iron (Fe)** | Balance | Balance | Balance | - | **Key Metric:** **PREN (Cr + 3.3Mo + 16N) ≥ 43**, placing it among the highest of all stainless steels. ### **3. Physical & Mechanical Properties** *Properties are typical for solution annealed material (min 1150°C water quench).* **Mechanical Properties:** * **Tensile Strength (Rm):** 650 - 850 MPa (94 - 123 ksi) * **Yield Strength (Rp0.2):** 300 MPa min (44 ksi min) *[Note: Significantly higher than 316L or 904L due to N strengthening]* * **Elongation (A):** 35% min * **Hardness (typical):** 95 - 115 HRB (200 - 240 HV) * **Modulus of Elasticity:** 200 GPa (29 x 10⁶ psi) * **Charpy V-Notch Impact:** Excellent, typically >100 J at -196°C. **Physical Properties:** * **Density:** 8.0 g/cm³ (0.289 lb/in³) * **Melting Range:** 1320 - 1390 °C (2410 - 2535 °F) * **Thermal Conductivity:** 13.5 W/m·K (at 20°C) * **Coefficient of Thermal Expansion:** 16.0 x 10⁻⁶ /K (20-100°C) *[Higher than carbon steel]* * **Magnetic Permeability:** < 1.05 (fully austenitic and non-magnetic when annealed) **Corrosion Resistance Key Metrics:** * **Critical Pitting Temperature (CPT):** Typically > 75°C in ASTM G48 Method A (6% FeCl₃). * **Critical Crevice Temperature (CCT):** Typically > 50°C, far exceeding conventional grades. * **Stress Corrosion Cracking (SCC):** Exceptional resistance in hot chloride solutions. ### **4. Key Characteristics** * **Unrivaled Chloride Resistance:** The benchmark for resisting pitting and crevice corrosion in seawater, brackish water, and chloride-rich process streams, even under stagnant or low-flow conditions. * **High Strength:** The high nitrogen content provides significant solid solution strengthening, resulting in a yield strength approximately 50% higher than 316L, allowing for thinner, lighter sections. * **Excellent SCC Resistance:** The combined high levels of nickel, chromium, molybdenum, and nitrogen impart superb resistance to chloride-induced stress corrosion cracking. * **Good Weldability:** Can be welded using all standard methods, but requires care to preserve corrosion resistance. Must use over-alloyed filler metals (e.g., AWS A5.14 ERNiCrMo-3/4) and avoid excessive heat input to prevent secondary phase precipitation. * **Good Fabricability:** Can be cold formed and machined, but its high strength and work hardening rate require more power and specialized techniques compared to standard austenitics. ### **5. Product Applications** Outokumpu 254 SMO® is specified for the world's most demanding applications where chloride corrosion is the primary threat: * **Seawater & Offshore:** Seawater cooling piping, heat exchanger tubes, pump casings, shafts, ballast systems, and offshore platform components. * **Desalination Plants:** High-pressure RO membranes housings, heat exchanger tubes in multi-stage flash (MSF) and multi-effect distillation (MED) units, and brine heaters. * **Chemical & Petrochemical:** Process equipment handling wet chlorine gas, hypochlorite, chloride-contaminated organic acids, and severe oxidizing acids. * **Pollution Control (FGD):** Absorber towers, mist eliminators, ducting, and dampers in flue gas desulfurization systems. * **Pulp & Paper:** Equipment in bleaching plants (ClO₂ stages) and chemical recovery lines. * **Marine & Shipbuilding:** Propeller shafts, rudders, seawater valves, and exhaust scrubber systems. ### **6. International Standards & Specifications** 254 SMO® is covered by major international material standards. | Region/System | Standard & Designation | Form/Product Standard | |---------------|----------------------|----------------------| | **UNS / ASTM** | **UNS S31254** | Unified Numbering System | | **ASTM / ASME** | **ASTM A240 / ASME SA-240** | Plate, Sheet, and Strip | | **ASTM / ASME** | **ASTM A312 / ASME SA-312** | Seamless and Welded Pipe | | **ASTM / ASME** | **ASTM B688 / ASME SB-688** | Welded Pipe (Chromium-Nickel-Molybdenum-Iron) | | **European (EN)** | **1.4547** (X1CrNiMoCuN20-18-7) | EN 10088-2 (Sheet/Plate), EN 10216-5 (Seamless Pipe) | | **Germany (DIN)** | **DIN 1.4547** | - | | **Japan (JIS)** | **SUS 312L** | - | | **ISO** | **ISO 15510: X1CrNiMoCuN20-18-7** | - | ### **7. Available Forms & Processing** * **Standard Forms:** Sheet, plate, strip, bar, wire, seamless and welded pipe & tube, fittings, and forgings. * **Condition:** Supplied in the **solution annealed and quenched** condition to ensure all carbides and intermetallic phases are dissolved, guaranteeing optimal corrosion resistance. * **Fabrication:** * **Welding:** **Critical Procedure.** Use TIG/GTAW with matching or over-alloyed filler (ERNiCrMo-3/4, e.g., Outokumpu P12). Keep heat input low, use stringer beads, and ensure rapid cooling. Post-weld pickling is highly recommended. * **Machining:** Requires rigid tooling, positive rake angles, sharp tools, and adequate cooling/lubrication. Power requirements are higher than for 316. * **Forming:** Cold forming is possible but requires greater force. Intermediate annealing may be necessary for severe deformations. ### **8. Why Choose Outokumpu 254 SMO®?** Outokumpu is the original developer of this grade and offers unparalleled expertise: * **Original Developer & Quality Leader:** Guarantees the original, optimized composition and metallurgy. * **Superior Product Consistency:** Advanced melting and refining processes (AOD, VOD, ESR) ensure ultra-low impurity levels and homogeneity. * **Comprehensive Technical Support:** Provides extensive data and application engineering for the most challenging environments. * **Proven Long-Term Performance:** Decades of documented success in critical applications worldwide, offering a cost-effective alternative to nickel alloys. --- **Disclaimer:** This datasheet provides general information. For applications in aggressive environments, especially under tensile stress, specific corrosion testing is advised. The high thermal expansion coefficient must be considered in system design. Always consult Outokumpu's latest technical manuals and engage with their application specialists for design, fabrication, and qualification of welding procedures. 254 SMO® is a registered trademark of Outokumpu Oyj. -:- For detailed product information, please contact sales. -: Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Specification Dimensions Size： Diameter 20-1000 mm Length <7400 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Flange -:- For detailed product information, please contact sales. -: Chemical Identifiers Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Flange -:- For detailed product information, please contact sales. -:

Packing of Outokumpu 254 SMO® High Performance Austenitic Stainless Steel Flange -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3871 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition