ASTM A543 Low Alloy Steel Flange, Grade B, Class 2

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. -: ASTM A543 Low Alloy Steel Flange, Grade B, Class 2 Product Information -:- For detailed product information, please contact sales. -: ASTM A543 Low Alloy Steel Flange, Grade B, Class 2 Synonyms -:- For detailed product information, please contact sales. -:

ASTM A543 Low Alloy Steel, Grade B, Class 2 Product Information -:- For detailed product information, please contact sales. -: ### **ASTM A543 Grade B Class 2: High-Strength Nickel-Chromium-Molybdenum Alloy Steel Plate** #### **1. Overview** ASTM A543 Grade B Class 2 is a **high-strength nickel-chromium-molybdenum alloy steel plate** supplied in the **quenched and tempered condition**. This intermediate strength class provides enhanced mechanical properties compared to Class 1 while maintaining excellent low-temperature toughness. Designed for pressure vessel applications requiring superior performance at cryogenic temperatures, this material offers an optimal balance of strength, toughness, and weldability for demanding service conditions. #### **2. Chemical Composition** The chemical composition maintains precise control for enhanced performance: | Element | Composition (%) | |---------|-----------------| | Carbon (C) | 0.20 max | | Manganese (Mn) | 0.20 - 0.60 | | Phosphorus (P) | 0.025 max | | Sulfur (S) | 0.025 max | | Silicon (Si) | 0.15 - 0.40 | | Nickel (Ni) | 2.00 - 3.50 | | Chromium (Cr) | 1.00 - 1.90 | | Molybdenum (Mo) | 0.40 - 0.60 | **Enhanced Composition Features:** - **Optimized Nickel Content (2.00-3.50%)**: Maintains exceptional low-temperature toughness at higher strength levels - **Chromium-Molybdenum Synergy**: Provides enhanced hardenability and strength retention - **Controlled Carbon Equivalent**: Ensures good weldability despite increased strength requirements - **Balanced Alloy System**: Delivers consistent performance in heavy sections #### **3. Physical & Mechanical Properties** **Mechanical Properties (Quenched & Tempered Condition):** | Property | Requirement | |----------|-------------| | **Tensile Strength** | 115 - 145 ksi (795 - 1000 MPa) | | **Yield Strength** | 95 ksi min (655 MPa min) | | **Elongation in 2 inches** | 15% min | | **Reduction of Area** | 35% min | | **Charpy V-Notch Impact** | 40 ft-lb min at -100°F (-73°C) | **Enhanced Performance Characteristics:** - **Superior Strength-Toughness Combination**: Maintains excellent impact properties at increased strength levels - **Excellent Low-Temperature Performance**: Reliable operation in cryogenic service conditions - **Enhanced Hardenability**: Consistent through-thickness properties in thicker sections - **Stable Mechanical Properties**: Predictable performance under thermal and mechanical cycling **Physical Properties (Typical):** - **Density**: 0.285 lb/in³ (7,890 kg/m³) - **Modulus of Elasticity**: 29,000 ksi (200 GPa) - **Thermal Expansion Coefficient**: 6.3 × 10⁻⁶/°F (11.3 × 10⁻⁶/°C) - **Thermal Conductivity**: 26.0 W/m·K at 212°F (100°C) - **Poisson's Ratio**: 0.29 #### **4. Product Applications** Grade B Class 2 is specified for applications requiring enhanced strength with maintained low-temperature toughness: **Advanced Cryogenic Systems:** - LNG storage tanks and processing equipment - Cryogenic pressure vessels - Low-temperature storage systems - Cryogenic transport and handling equipment **Power Generation:** - Nuclear power plant components - High-pressure turbine casings - Advanced power generation systems - Energy conversion equipment **Chemical Processing:** - High-pressure chemical reactors - Low-temperature process vessels - Petrochemical synthesis equipment - Specialized process industry applications #### **5. International Standards & Equivalents** | Region/Country | Standard | Equivalent Grade | Notes | |----------------|----------|------------------|-------| | **International** | **ISO 9328-2** | 12Ni14 | Similar nickel steel grade | | **Europe** | **EN 10028-4** | 12Ni14 | Low temperature nickel steel | | **Japan** | **JIS G3127** | SL3N255 | Low temperature pressure vessel steel | | **Germany** | **DIN 17280** | 12Ni14 | Cryogenic nickel steel equivalent | **Grade B Class Mechanical Comparison:** | Parameter | Class 1 | Class 2 | Class 3 | |-----------|---------|---------|---------| | **Yield Strength Minimum** | 85 ksi | 95 ksi | 105 ksi | | **Tensile Strength Range** | 105-135 ksi | 115-145 ksi | 125-155 ksi | | **Impact Test Temperature** | -100°F | -100°F | -100°F | | **Typical Hardness Range** | 240-300 HBW | 260-320 HBW | 280-340 HBW | #### **6. Fabrication & Quality Assurance** **Advanced Welding Technology:** - **Pre-heat requirement**: 325-425°F (163-218°C) minimum - **Post-weld heat treatment**: Required at 1125-1225°F (607-663°C) - **Welding consumables**: Low-hydrogen electrodes with matching strength - **Interpass temperature control**: 425-575°F (218-302°C) maximum - **Advanced procedure qualification**: Mandatory for all welding operations **Precision Heat Treatment:** - **Austenitizing temperature**: 1550-1650°F (845-900°C) with strict control - **Quenching process**: Accelerated cooling with optimized rates - **Tempering range**: 1150-1350°F (621-732°C) for property development - **Microstructural verification**: Fully tempered martensitic/bainitic structure **Enhanced Quality Control:** - **Impact testing**: Required at -100°F (-73°C) for each heat treatment charge - **Tension tests**: Multiple locations and orientations - **Ultrasonic examination**: Per supplementary requirements when specified - **Hardness survey**: Typically 260-320 HBW --- **Technical Advantages:** - **Enhanced strength** with maintained low-temperature toughness - **Excellent cryogenic performance** for severe service conditions - **Superior hardenability** in heavy sections - **Good fabricability** despite increased strength levels **Design and Engineering Considerations:** - **ASME Section VIII Division 2** design methodology applicable - **Low-temperature service** capability maintained to -100°F (-73°C) - **Fracture mechanics assessment** recommended for critical applications - **Advanced NDE requirements** for quality verification **Service Limitations and Guidelines:** - **Minimum design temperature**: -100°F (-73°C) - **Maximum service temperature**: 750°F (400°C) - **Welding considerations**: Strict procedure control essential - **Quality verification**: Enhanced testing requirements for critical applications **Disclaimer:** This technical information is for reference purposes only. For pressure vessel applications involving cryogenic service, consult the latest ASTM A543 specification and applicable ASME Code requirements. Material selection, fabrication, and testing must be approved by qualified engineers and comply with all relevant regulatory standards and quality assurance protocols. -:- For detailed product information, please contact sales. -: ASTM A543 Low Alloy Steel, Grade B, Class 2 Specification Dimensions Size： Diameter 20-1000 mm Length <4454 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. -: ASTM A543 Low Alloy Steel, Grade B, Class 2 Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A543 Low Alloy Steel Flange, Grade B, Class 2 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A543 Low Alloy Steel Flange, Grade B, Class 2 -:- For detailed product information, please contact sales. -:

Packing of ASTM A543 Low Alloy Steel Flange, Grade B, Class 2 -:- 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 925 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