ASTM A387 Alloy Steel Tube,Pipe, Grade 21, Class 1

ASTM A387 Alloy Steel Tube, Grade 21, Class 1 Product Information -:- For detailed product information, please contact sales. -: ASTM A387 Alloy Steel Tube, Grade 21, Class 1 Synonyms -:- For detailed product information, please contact sales. -:

ASTM A387 Alloy Steel, Grade 21, Class 1 Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: ASTM A387 Grade 21 Class 1 Steel** **ASTM A387 Grade 21 Class 1** is a chromium-molybdenum alloy steel plate designed for high-temperature pressure vessel applications, offering enhanced corrosion resistance and elevated temperature strength. This specification covers plates in the annealed or normalized and tempered condition, suitable for welded pressure vessels operating in severe service environments. --- #### **1. International Standards & Classification** **Primary Standard:** **ASTM A387/A387M** - "Standard Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum" **Grade Classification:** - **Grade 21** - 3.0% Chromium - 1.0% Molybdenum alloy steel - **Class 1** - Annealed or normalized and tempered condition **International Equivalents:** - **EN 10028-2**: 16CrMo5-5 - **JIS G4109**: SCMV 6 - **GB/T 3077**: 20Cr3MoWVA - **ISO 9328-2**: 16CrMo5-5 --- #### **2. Chemical Composition** The chemical composition requirements for ASTM A387 Grade 21: | Element | Composition (Maximum %) | |---|---| | Carbon (C) | 0.05-0.15 | | Manganese (Mn) | 0.30-0.60 | | Phosphorus (P) | 0.035 | | Sulfur (S) | 0.035 | | Silicon (Si) | 0.50 | | Chromium (Cr) | 2.75-3.25 | | Molybdenum (Mo) | 0.90-1.10 | **Key Composition Features:** - **Higher Chromium Content**: 2.75-3.25% for superior oxidation and corrosion resistance - **Enhanced Molybdenum**: 0.90-1.10% for improved creep strength - **Controlled Carbon**: 0.05-0.15% for optimal weldability and toughness - **Lower Manganese**: 0.30-0.60% for better high-temperature properties --- #### **3. Physical & Mechanical Properties** **Mechanical Properties (Class 1 condition):** | Property | Value | |---|---| | **Tensile Strength** | 515-690 MPa (75-100 ksi) | | **Yield Strength (min.)** | 310 MPa (45 ksi) | | **Elongation in 2" (min.)** | 18% | | **Elongation in 8" (min.)** | 20% | **Elevated Temperature Properties:** - **Maximum Service Temperature**: Up to 650°C (1200°F) - **Creep Strength**: Excellent resistance to creep deformation - **Oxidation Resistance**: Superior performance in oxidizing atmospheres - **Hydrogen Resistance**: Good resistance to hydrogen attack **Physical Properties:** - **Density**: 7.87 g/cm³ (0.284 lb/in³) - **Modulus of Elasticity**: 205 GPa (29,700 ksi) - **Thermal Conductivity**: 42.5 W/m·K - **Coefficient of Thermal Expansion**: 11.5 × 10⁻⁶/°C - **Specific Heat Capacity**: 460 J/kg·K --- #### **4. Product Applications** **High-Temperature Pressure Vessels:** - Hydrocracking reactors - Hydrogen processing vessels - High-temperature reactors - Severe service pressure vessels **Power Generation:** - High-pressure steam components - Advanced boiler systems - High-temperature heat exchangers - Power plant reformer tubes **Petrochemical Industry:** - Catalytic reforming units - Hydrogenation reactors - High-temperature process vessels - Refinery hydroprocessing equipment **Special Applications:** - Synthetic fuel processing equipment - High-temperature chemical reactors - Advanced energy systems - High-pressure high-temperature (HPHT) equipment --- #### **5. Fabrication Characteristics** **Welding Performance:** - **Fair Weldability**: Requires careful procedure control - **Preheat Requirements**: 200-250°C (400-480°F) minimum - **Post-Weld Heat Treatment**: Mandatory at 690-730°C (1275-1350°F) - **Recommended Processes**: GTAW, SMAW (low-hydrogen) - **Filler Metals**: E9015-B3, ER90S-B3 or equivalent **Forming & Machining:** - **Moderate Formability**: Hot forming required for complex shapes - **Machinability**: Fair to poor (approximately 45% of B1112 steel) - **Cutting Methods**: Plasma and waterjet cutting recommended - **Hot Working Temperature**: 1050-1200°C (1920-2190°F) **Heat Treatment:** - Supplied in annealed or normalized and tempered condition - Normalizing temperature: 925-955°C (1700-1750°F) - Tempering temperature: 675-705°C (1250-1300°F) - Annealing temperature: 845-875°C (1550-1600°F) **Quality Assurance:** - **Comprehensive Testing**: Full mechanical and chemical analysis - **Impact Testing**: Required for pressure vessel applications - **Hardness Testing**: Mandatory quality control - **Non-Destructive Testing**: UT, RT, MT as specified --- ### **Technical Summary** ASTM A387 Grade 21 Class 1 represents an advanced chromium-molybdenum alloy steel specifically designed for severe high-temperature and high-pressure applications. The 3% chromium content provides significantly improved oxidation and corrosion resistance compared to lower alloy grades, while the 1% molybdenum content ensures excellent creep strength and high-temperature stability. This grade is particularly suitable for applications involving hydrogen service at elevated temperatures and pressures, where resistance to hydrogen attack is crucial. The enhanced alloy composition makes it ideal for hydrocracking reactors, hydrogen processing equipment, and other severe service applications in the petrochemical and refining industries. While requiring more sophisticated fabrication techniques and stringent quality controls, Grade 21 Class 1 delivers reliable performance in the most demanding service conditions. The material's proven track record in high-temperature hydrogen service and its ability to withstand aggressive corrosive environments have established it as a preferred choice for critical pressure vessel applications where conventional chromium-molybdenum steels would be inadequate. The balanced combination of high-temperature strength, corrosion resistance, and hydrogen service capability makes ASTM A387 Grade 21 Class 1 an essential material for advanced energy systems, petrochemical processing, and high-temperature pressure vessel applications where performance reliability and long-term service integrity are paramount considerations. -:- For detailed product information, please contact sales. -: ASTM A387 Alloy Steel, Grade 21, Class 1 Specification Dimensions Size： Diameter 20-1000 mm Length <4366 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 A387 Alloy Steel, Grade 21, Class 1 Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A387 Alloy Steel Tube, Grade 21, Class 1 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A387 Alloy Steel Tube, Grade 21, Class 1 -:- For detailed product information, please contact sales. -:

Packing of ASTM A387 Alloy Steel Tube, Grade 21, Class 1 -:- 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 Tube 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 837 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