ASTM A678 Steel Seamless tube, grade A

ASTM A678 Steel Seamless tube, grade A Product Information -:- For detailed product information, please contact sales. -: ASTM A678 Steel Seamless tube, grade A Synonyms -:- For detailed product information, please contact sales. -:

ASTM A678 Steel, grade A Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: ASTM A678 Grade A Steel** **ASTM A678 Grade A** is a high-strength, quenched and tempered carbon steel plate specifically designed for structural applications requiring superior mechanical properties and enhanced toughness. As part of the A678 specification for quenched and tempered carbon steel plates, Grade A offers an excellent balance of strength, weldability, and impact resistance, making it suitable for critical structural components in demanding service environments. --- #### **1. International Standards & Grades** **Primary Standard:** **ASTM A678/A678M** - "Standard Specification for Quenched-and-Tempered Carbon Steel Plates for Structural Applications" **Grade Classification:** - **Grade A** - Minimum yield strength 50 ksi (345 MPa) - Other grades in A678 series: B, C, D **International Equivalents:** - **EN 10025-6**: S500Q/S500QL - **JIS G3106**: SM570 - **GB/T 16270**: Q500 - **ISO 4950-3**: EQ500 --- #### **2. Chemical Composition** The chemical composition requirements for ASTM A678 Grade A: | Element | Composition (Maximum %) | |---|---| | Carbon (C) | 0.20 | | Manganese (Mn) | 1.00-1.60 | | Phosphorus (P) | 0.035 | | Sulfur (S) | 0.040 | | Silicon (Si) | 0.15-0.50 | | Copper (Cu) | 0.35 (when specified) | **Key Composition Features:** - **Optimized Carbon Content**: Balances strength and weldability - **Enhanced Manganese Range**: Provides hardenability and strength - **Controlled Silicon**: Aids in deoxidation and strength enhancement - **Optional Copper**: Improves atmospheric corrosion resistance --- #### **3. Physical & Mechanical Properties** **Mechanical Properties (for thicknesses up to 2.5 inches/63 mm):** | Property | Value | |---|---| | **Tensile Strength** | 550-690 MPa (80-100 ksi) | | **Yield Strength (min.)** | 345 MPa (50 ksi) | | **Elongation in 2" (min.)** | 18% | | **Elongation in 8" (min.)** | 21% | **Impact Toughness Properties:** - **Charpy V-Notch Test Temperature**: 70°F (21°C) - **Minimum Impact Energy**: 20 ft-lbf (27 J) **Physical Properties:** - **Density**: 7.85 g/cm³ (0.284 lb/in³) - **Modulus of Elasticity**: 200 GPa (29,000 ksi) - **Poisson's Ratio**: 0.29 - **Thermal Conductivity**: 48.0 W/m·K - **Coefficient of Thermal Expansion**: 11.8 × 10⁻⁶/°C --- #### **4. Product Applications** **Structural Engineering:** - Bridge components and girders - Building structural frames - Industrial plant structures - Crane and hoist support members **Heavy Equipment Manufacturing:** - Construction machinery frames - Mining equipment components - Material handling structures - Heavy press frames **Transportation Infrastructure:** - Railway bridge components - Heavy-duty trailer frames - Transportation equipment structures - Port facility components **Energy Sector:** - Power plant structural members - Transmission tower components - Wind turbine structures - Hydroelectric plant components **Industrial Applications:** - Heavy-duty storage systems - Industrial platform structures - Machinery support frames - Equipment base plates --- #### **5. Fabrication Characteristics** **Welding Performance:** - **Good Weldability**: With proper procedure control - **Preheat Requirements**: 200-300°F (95-150°C) depending on thickness - **Recommended Processes**: SMAW, GMAW, FCAW, SAW - **Filler Metals**: E80XX series electrodes or equivalent **Forming & Machining:** - **Moderate Formability**: Suitable for most structural forming operations - **Bend Radius**: Typically 2.5t for 90° bends - **Machinability**: Fair (approximately 50% of B1112 steel) - **Cutting Methods**: Plasma, laser, and waterjet cutting recommended **Heat Treatment:** - Supplied in quenched and tempered condition - Maximum hardness: 302 HBW - Through-thickness properties maintained **Quality Assurance:** - Charpy V-Notch impact testing required - Multiple tests per plate as specified - Full certification of mechanical properties --- ### **Technical Summary** ASTM A678 Grade A represents a premium quenched and tempered carbon steel plate that offers an excellent combination of high strength and enhanced toughness for structural applications. The controlled quenching and tempering heat treatment process provides superior mechanical properties compared to as-rolled carbon steels, making it particularly suitable for applications subject to dynamic loading and impact conditions. The grade's balanced chemical composition ensures good weldability while maintaining the required strength and toughness characteristics. Its 50 ksi minimum yield strength provides significant advantages in weight-sensitive designs where structural efficiency is paramount. The material's consistent performance and reliable mechanical properties have established it as a preferred choice for critical structural components in bridge construction, heavy equipment manufacturing, and industrial applications. While requiring careful attention to welding procedures and fabrication techniques, ASTM A678 Grade A delivers dependable performance in demanding service conditions. Its certified impact properties and guaranteed mechanical characteristics provide engineers with confidence in structural designs where safety and reliability are essential considerations. -:- For detailed product information, please contact sales. -: ASTM A678 Steel, grade A Specification Dimensions Size： Diameter 20-1000 mm Length <4306 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 A678 Steel, grade A Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A678 Steel Seamless tube, grade A -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A678 Steel Seamless tube, grade A -:- For detailed product information, please contact sales. -:

Packing of ASTM A678 Steel Seamless tube, grade A -:- 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 Seamless 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 777 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