ASTM A542 Low Alloy Steel, Grade A, Class 2

ASTM A542 Low Alloy Steel, Grade A, Class 2 Product Information -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel, Grade A, Class 2 Synonyms -:- For detailed product information, please contact sales. -:

ASTM A542 Low Alloy Steel, Grade A, Class 2 Product Information -:- For detailed product information, please contact sales. -: ### **ASTM A542 Grade A Class 2: Elevated Temperature Chromium-Molybdenum Steel Plate** #### **1. Overview** ASTM A542 Grade A Class 2 is a **quenched and tempered chromium-molybdenum alloy steel plate** designed for **pressure vessel applications** requiring enhanced mechanical properties at elevated temperatures. This intermediate strength class offers improved yield and tensile strength compared to Class 1 while maintaining good toughness and excellent creep resistance, making it suitable for high-temperature pressure containment in petroleum refining and power generation equipment. #### **2. Chemical Composition** The chemical composition maintains precise control for consistent high-temperature performance: | 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 | **Optimized Composition Features:** - **Low Carbon Maximum (0.15%)**: Ensures excellent weldability and notch toughness - **Chromium-Molybdenum Balance**: Provides optimal oxidation resistance and creep strength - **Restricted Manganese Range**: Controls hardenability for consistent through-thickness properties - **Enhanced Purity**: Low phosphorus and sulfur contents improve high-temperature ductility #### **3. Physical & Mechanical Properties** **Mechanical Properties (Quenched & Tempered Condition):** | Property | Requirement | |----------|-------------| | **Tensile Strength** | 85 - 105 ksi (585 - 725 MPa) | | **Yield Strength** | 60 ksi min (415 MPa min) | | **Elongation in 2 inches** | 17% min | | **Reduction of Area** | 40% min | | **Charpy V-Notch Impact** | 35 ft-lb min at -50°F (-46°C) | **Elevated Temperature Performance:** - **Creep Rupture Strength**: Excellent long-term performance at temperatures up to 1000°F (540°C) - **Oxidation Resistance**: Suitable for continuous service up to 1100°F (595°C) - **Thermal Fatigue Resistance**: Good resistance to thermal cycling conditions **Physical Properties (Typical):** - **Density**: 0.283 lb/in³ (7,830 kg/m³) - **Modulus of Elasticity**: 29,300 ksi (202 GPa) at 70°F (21°C) - **Mean Coefficient of Thermal Expansion**: 6.3 × 10⁻⁶/°F (11.3 × 10⁻⁶/°C) from 70-1000°F - **Thermal Conductivity**: 27.0 W/m·K at 212°F (100°C) #### **4. Product Applications** Grade A Class 2 is specified for intermediate high-temperature pressure vessel applications: **Petroleum Refining Equipment:** - Hydrodesulfurization reactors - High-pressure separators - Catalytic reforming vessels - Intermediate temperature process equipment **Power Generation Components:** - Intermediate pressure steam drums - Power boiler components - High-temperature heat exchangers - Turbine bypass systems **Chemical Process Industry:** - Moderate temperature chemical reactors - High-pressure process vessels - Synthesis gas equipment - Petrochemical conversion units #### **5. International Standards & Equivalents** | Region/Country | Standard | Equivalent Grade | Notes | |----------------|----------|------------------|-------| | **International** | **ISO 9328-2** | 13CrMo4-5 | Similar chromium-molybdenum composition | | **Europe** | **EN 10028-2** | 13CrMo4-5 | Comparable elevated temperature properties | | **Japan** | **JIS G4109** | SCMV 4 | Chromium-molybdenum pressure vessel steel | | **Germany** | **DIN 17155** | 13CrMo44 | Well-established equivalent grade | **A542 Grade A Class 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 | | **Application Temperature** | Moderate | Intermediate | High | #### **6. Fabrication & Quality Assurance** **Welding and Fabrication Requirements:** - **Mandatory pre-heating**: 350-450°F (175-230°C) depending on thickness - **Post-weld heat treatment**: Required at 1150-1250°F (620-675°C) - **Welding consumables**: Low-hydrogen electrodes with matching composition - **Interpass temperature control**: 400-600°F (200-315°C) maximum **Heat Treatment Protocol:** - **Austenitizing temperature**: 1650-1700°F (900-925°C) - **Quenching medium**: Water or accelerated cooling required - **Tempering range**: 1200-1350°F (650-730°C) - **Microstructural requirements**: Fully tempered microstructure mandatory **Quality Control and Testing:** - **Impact testing**: At specified temperature for each heat treatment charge - **Tension tests**: From representative locations of each plate - **Hardness verification**: Typically 200-250 HBW - **Ultrasonic examination**: Per supplementary requirements when specified --- **Technical Advantages:** - **Enhanced strength** at intermediate temperature ranges - **Good resistance to hydrogen attack** in refinery service - **Excellent thermal stability** during long-term exposure - **Superior fabricability** compared to higher alloy grades **Design and Application Considerations:** - **ASME Section VIII Division 1** design rules applicable - **Creep life assessment** recommended for temperatures above 800°F (425°C) - **Environmental degradation** factors must be considered - **Cyclic service evaluation** for thermal fatigue applications **Service Limitations:** - **Maximum design temperature**: 1100°F (595°C) for continuous service - **Minimum design temperature**: -50°F (-46°C) based on impact requirements - **Hydrogen service limitations**: Per API 941 Nelson Curve requirements - **Oxidation limits**: Based on service environment and temperature **Disclaimer:** This technical information is for reference purposes. For pressure vessel applications, consult the latest ASTM A542 specification and applicable ASME Code requirements. All design, material selection, and fabrication activities must be approved by qualified engineers and comply with relevant regulatory standards. -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel, Grade A, Class 2 Specification Dimensions Size： Diameter 20-1000 mm Length <4438 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 2 Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A542 Low Alloy Steel, Grade A, Class 2 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A542 Low Alloy Steel, Grade A, Class 2 -:- For detailed product information, please contact sales. -:

Packing of ASTM A542 Low Alloy Steel, Grade A, 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 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 909 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