ASTM A542 Low Alloy Steel Flange, Grade A, Class 3

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 A542 Low Alloy Steel Flange, Grade A, Class 3 Product Information -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel Flange, Grade A, Class 3 Synonyms -:- For detailed product information, please contact sales. -:

ASTM A542 Low Alloy Steel, Grade A, Class 3 Product Information -:- For detailed product information, please contact sales. -: ### **ASTM A542 Grade A Class 3: High-Strength Chromium-Molybdenum Steel Plate** #### **1. Overview** ASTM A542 Grade A Class 3 is a **high-strength chromium-molybdenum alloy steel plate** supplied in the **quenched and tempered condition** for pressure vessel applications requiring maximum strength retention at elevated temperatures. This class represents the highest strength level within the Grade A classification, providing superior mechanical properties while maintaining adequate toughness for high-temperature service in demanding refinery and power generation applications. #### **2. Chemical Composition** The chemical composition is precisely controlled to achieve maximum strength capabilities: | Element | Composition (%) | |---------|-----------------| | Carbon (C) | 0.15 max | | Manganese (Mn) | 0.30 - 0.60 | | Phosphorus (P) | 0.025 max | | Sulfur (S) | 0.025 max | | Silicon (Si) | 0.15 - 0.40 | | Chromium (Cr) | 1.00 - 1.50 | | Molybdenum (Mo) | 0.45 - 0.60 | **Advanced Composition Features:** - **Ultra-Low Carbon Content**: Maximizes weldability and toughness at high strength levels - **Optimized Chromium-Molybdenum Ratio**: Provides excellent high-temperature strength and oxidation resistance - **Tight Compositional Control**: Ensures consistent heat treatment response - **Enhanced Purity Levels**: Superior cleanliness for improved fracture resistance #### **3. Physical & Mechanical Properties** **Mechanical Properties (Quenched & Tempered Condition):** | Property | Requirement | |----------|-------------| | **Tensile Strength** | 95 - 115 ksi (655 - 795 MPa) | | **Yield Strength** | 70 ksi min (485 MPa min) | | **Elongation in 2 inches** | 16% min | | **Reduction of Area** | 35% min | | **Charpy V-Notch Impact** | 30 ft-lb min at -50°F (-46°C) | **High-Temperature Performance:** - **Enhanced Creep Strength**: Superior resistance to deformation at temperatures up to 1100°F (595°C) - **Oxidation Resistance**: Maintains integrity in oxidizing atmospheres - **Thermal Stability**: Excellent microstructural stability during prolonged high-temperature exposure **Physical Properties (Typical):** - **Density**: 0.283 lb/in³ (7,830 kg/m³) - **Modulus of Elasticity**: 29,100 ksi (201 GPa) at room temperature - **Thermal Expansion Coefficient**: 6.4 × 10⁻⁶/°F (11.5 × 10⁻⁶/°C) from 70-1000°F - **Thermal Conductivity**: 26.0 W/m·K at 212°F (100°C) #### **4. Product Applications** Grade A Class 3 is specified for the most demanding high-temperature, high-pressure applications: **Petroleum Refining:** - High-pressure hydrocracking reactors - Severe service hydrotreating vessels - Critical refinery process equipment - High-temperature high-pressure separators **Power Generation:** - High-pressure steam drums and headers - Advanced boiler components - Critical power plant piping systems - High-temperature heat exchangers **Chemical Processing:** - Severe service chemical reactors - High-pressure synthesis vessels - Demanding process industry equipment - Advanced petrochemical units #### **5. International Standards & Equivalents** | Region/Country | Standard | Equivalent Grade | Notes | |----------------|----------|------------------|-------| | **International** | **ISO 9328-2** | 13CrMo4-5 | High-strength variant | | **Europe** | **EN 10028-2** | 13CrMo4-5 | Similar elevated temperature properties | | **Japan** | **JIS G4109** | SCMV 4 | High-strength chromium-molybdenum steel | | **Germany** | **DIN 17155** | 13CrMo44 | Well-established equivalent | **Complete Grade A Property Comparison:** | Parameter | Class 1 | Class 2 | Class 3 | |-----------|---------|---------|---------| | **Yield Strength Minimum** | 50 ksi | 60 ksi | 70 ksi | | **Tensile Strength Range** | 75-95 ksi | 85-105 ksi | 95-115 ksi | | **Impact Energy Requirement** | 40 ft-lb | 35 ft-lb | 30 ft-lb | #### **6. Fabrication & Quality Assurance** **Advanced Welding Technology:** - **Strict pre-heat requirements**: 400-500°F (200-260°C) minimum - **Precise interpass control**: 450-550°F (230-290°C) maximum - **Post-weld heat treatment**: Mandatory at 1175-1275°F (635-690°C) - **Specialized welding consumables**: High-strength matching composition required **Precision Heat Treatment:** - **Austenitizing**: 1650-1700°F (900-925°C) with strict uniformity - **Quenching**: Accelerated cooling with precise rate control - **Tempering**: 1225-1375°F (665-745°C) for optimal property development - **Quality verification**: Comprehensive mechanical testing required **Enhanced Quality Control:** - **Ultrasonic examination**: Per ASTM A578 Level II minimum - **Impact testing**: Multiple locations and orientations - **Tensile testing**: Longitudinal and transverse directions - **Hardness survey**: Typically 225-275 HBW --- **Technical Advantages:** - **Maximum strength capability** within Grade A classification - **Excellent high-temperature mechanical properties** - **Good resistance to hydrogen environment embrittlement** - **Superior creep rupture strength** **Design and Engineering Considerations:** - **ASME Section VIII Division 2** design methods recommended - **Advanced creep analysis** required for high-temperature applications - **Fracture mechanics evaluation** for critical service conditions - **Environmental degradation assessment** essential **Service Limitations and Guidelines:** - **Maximum continuous service temperature**: 1100°F (595°C) - **Minimum design temperature**: -50°F (-46°C) - **Hydrogen service**: Per API 941 Nelson Curve requirements - **Oxidation limits**: Dependent on specific service environment **Disclaimer:** This information is for technical reference purposes. For high-temperature pressure vessel applications, strict adherence to the latest ASTM A542 specification and applicable ASME Code requirements is mandatory. All design, material selection, and fabrication activities must be approved by qualified engineers and comply with relevant regulatory standards and quality assurance protocols. -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel, Grade A, Class 3 Specification Dimensions Size： Diameter 20-1000 mm Length <4439 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 A542 Low Alloy Steel, Grade A, Class 3 Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A542 Low Alloy Steel Flange, Grade A, Class 3 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A542 Low Alloy Steel Flange, Grade A, Class 3 -:- For detailed product information, please contact sales. -:

Packing of ASTM A542 Low Alloy Steel Flange, Grade A, Class 3 -:- 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 910 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