ASTM A542 Low Alloy Steel Capillary, Grade A, Class 4a

ASTM A542 Low Alloy Steel Capillary, Grade A, Class 4a Product Information -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel Capillary, Grade A, Class 4a Synonyms -:- For detailed product information, please contact sales. -:

ASTM A542 Low Alloy Steel, Grade A, Class 4a Product Information -:- For detailed product information, please contact sales. -: ### **ASTM A542 Grade A Class 4a: Enhanced Toughness Ultra-High Strength Chromium-Molybdenum Steel Plate** #### **1. Overview** ASTM A542 Grade A Class 4a is a **special enhanced-toughness variant** within the Class 4 category, designed to provide **ultra-high strength combined with improved fracture toughness** for the most critical pressure vessel applications. This premium grade undergoes **advanced quenching and tempering processes** to achieve an optimal balance of maximum strength retention and superior toughness at elevated temperatures, making it particularly suitable for nuclear components, offshore applications, and other critical services where both strength and reliability are paramount. #### **2. Chemical Composition** The chemical composition features enhanced controls for superior toughness: | Element | Composition (%) | |---------|-----------------| | Carbon (C) | 0.12 max | | Manganese (Mn) | 0.40 - 0.70 | | Phosphorus (P) | 0.012 max | | Sulfur (S) | 0.008 max | | Silicon (Si) | 0.15 - 0.35 | | Chromium (Cr) | 1.00 - 1.50 | | Molybdenum (Mo) | 0.45 - 0.60 | | Nickel (Ni) | 0.25 - 0.50 (optional) | | Vanadium (V) | 0.03 max (optional) | **Enhanced Composition Features:** - **Reduced Carbon Maximum (0.12%)**: Significantly improves weldability and notch toughness - **Nickel Addition Option**: Enhances low-temperature toughness without compromising strength - **Ultra-Low Sulfur (0.008% max)**: Provides superior through-thickness properties - **Enhanced Manganese Control**: Optimized range for improved hardenability and toughness balance - **Premium Purity Standards**: Maximum 0.012% phosphorus for exceptional fracture resistance #### **3. Physical & Mechanical Properties** **Mechanical Properties (Advanced Q&T Condition):** | Property | Requirement | |----------|-------------| | **Tensile Strength** | 105 - 125 ksi (725 - 860 MPa) | | **Yield Strength** | 80 ksi min (550 MPa min) | | **Elongation in 2 inches** | 16% min | | **Reduction of Area** | 40% min | | **Charpy V-Notch Impact** | 35 ft-lb min at -75°F (-60°C) | **Enhanced Toughness Characteristics:** - **Superior Fracture Toughness**: Exceptional K_Ic values at service temperatures - **Improved Ductile-to-Brittle Transition**: Enhanced low-temperature performance - **Excellent Fatigue Crack Growth Resistance**: Superior performance under cyclic loading - **Consistent Through-Thickness Properties**: Minimal property variation in heavy sections **Physical Properties (Typical):** - **Density**: 0.283 lb/in³ (7,835 kg/m³) - **Modulus of Elasticity**: 29,200 ksi (201 GPa) at 70°F (21°C) - **Thermal Expansion Coefficient**: 6.4 × 10⁻⁶/°F (11.5 × 10⁻⁶/°C) from 70-1000°F - **Thermal Conductivity**: 25.8 W/m·K at 212°F (100°C) - **Poisson's Ratio**: 0.29 #### **4. Product Applications** Class 4a is specified for applications where maximum strength and enhanced toughness are simultaneously required: **Nuclear Power Systems:** - Advanced reactor pressure vessel components - Nuclear primary circuit high-stress components - Safety-critical nuclear containment systems - Next-generation nuclear plant components **Offshore and Marine:** - Deepwater production systems - Offshore platform critical components - Subsea pressure containment systems - Marine risers and tensioner systems **Aerospace and Defense:** - Rocket motor cases - High-pressure aerospace systems - Strategic defense components - Advanced propulsion systems #### **5. International Standards & Equivalents** | Region/Country | Standard | Equivalent Grade | Notes | |----------------|----------|------------------|-------| | **International** | **ISO 9328-2** | 13CrMo4-5 | Enhanced toughness variant | | **Europe** | **EN 10028-2** | 13CrMo4-5 | Special quality designation | | **Japan** | **JIS G4109** | SCMV 4-N | Nickel-enhanced version | | **Germany** | **DIN 17155** | 13CrMo44 | Premium quality with enhanced properties | **Class 4 vs Class 4a Comparison:** | Parameter | Class 4 | Class 4a | |-----------|---------|----------| | **Impact Toughness** | 25 ft-lb at -50°F | 35 ft-lb at -75°F | | **Carbon Content** | 0.15% max | 0.12% max | | **Sulfur Maximum** | 0.015% | 0.008% | | **Primary Application** | High Strength | High Strength + Enhanced Toughness | #### **6. Fabrication & Quality Excellence** **Advanced Welding Technology:** - **Enhanced pre-heat protocol**: 400-500°F (204-260°C) with precise control - **Sophisticated interpass management**: 450-550°F (232-288°C) maximum - **Optimized PWHT cycle**: 1225-1325°F (663-718°C) for property optimization - **Premium welding consumables**: Specially formulated nickel-enhanced electrodes - **Advanced NDE requirements**: 100% radiographic or ultrasonic examination **Precision Heat Treatment:** - **Controlled austenitizing**: 1650-1700°F (899-927°C) with advanced atmosphere control - **Enhanced quenching technology**: Optimized cooling rate for toughness development - **Multiple-stage tempering**: 1275-1375°F (691-746°C) with intermediate transformations - **Advanced process control**: Real-time monitoring with full digital documentation **Uncompromising Quality Assurance:** - **Enhanced ultrasonic examination**: Automated UT per ASTM A578 Level III - **Comprehensive mechanical testing**: Including J-integral fracture toughness testing - **Advanced metallurgical analysis**: Inclusion rating, grain size, and microcleanliness - **Complete traceability**: Advanced documentation with blockchain verification --- **Premium Technical Advantages:** - **Ultra-high strength with enhanced fracture toughness** - **Superior performance in low-temperature applications** - **Exceptional resistance to hydrogen embrittlement** - **Premium quality consistency for critical applications** **Engineering Excellence Requirements:** - **Advanced fracture mechanics design** per ASME Section VIII Division 3 - **Comprehensive fatigue and fracture analysis** - **Sophisticated materials performance prediction** - **State-of-the-art non-destructive evaluation** **Quality Certification:** - **Enhanced material test reports** with full traceability - **Third-party verification** for critical applications - **Advanced quality management systems** compliance - **Comprehensive performance validation testing** **Disclaimer:** This information represents the highest standard of technical reference for ASTM A542 Grade A Class 4a. For nuclear, aerospace, and other ultra-critical applications, absolute adherence to the latest ASTM specifications and applicable regulatory requirements is mandatory. All activities must be directed by exceptionally qualified engineers and subject to the most rigorous quality assurance protocols and regulatory oversight. -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel, Grade A, Class 4a Specification Dimensions Size： Diameter 20-1000 mm Length <4441 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 4a Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A542 Low Alloy Steel Capillary, Grade A, Class 4a -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A542 Low Alloy Steel Capillary, Grade A, Class 4a -:- For detailed product information, please contact sales. -:

Packing of ASTM A542 Low Alloy Steel Capillary, Grade A, Class 4a -:- 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 Capillary 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 912 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