ASTM A678 Steel Sheet,Plate, grade B

ASTM A678 Steel Sheet/Plate, grade B Product Information -:- For detailed product information, please contact sales. -: ASTM A678 Steel Sheet/Plate, grade B Synonyms -:- For detailed product information, please contact sales. -:

ASTM A678 Steel, grade B Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: ASTM A678 Grade B Steel** **ASTM A678 Grade B** is a high-strength quenched and tempered carbon steel plate offering enhanced mechanical properties for demanding structural applications. As part of the A678 specification, Grade B provides superior strength and toughness characteristics through controlled heat treatment processes, making it suitable for critical components where reliability under heavy loading conditions is essential. --- #### **1. International Standards & Grades** **Primary Standard:** **ASTM A678/A678M** - "Standard Specification for Quenched-and-Tempered Carbon Steel Plates for Structural Applications" **Grade Classification:** - **Grade B** - Minimum yield strength 60 ksi (415 MPa) - Other grades in A678 series: A, C, D **International Equivalents:** - **EN 10025-6**: S550Q/S550QL - **JIS G3106**: SM570 - **GB/T 16270**: Q550 - **ISO 4950-3**: EQ550 --- #### **2. Chemical Composition** The chemical composition requirements for ASTM A678 Grade B: | Element | Composition (Maximum %) | |---|---| | Carbon (C) | 0.22 | | Manganese (Mn) | 1.10-1.60 | | Phosphorus (P) | 0.035 | | Sulfur (S) | 0.040 | | Silicon (Si) | 0.15-0.50 | | Copper (Cu) | 0.35 (when specified) | **Key Composition Features:** - **Controlled Carbon Content**: Optimized for strength and toughness balance - **Enhanced Manganese**: Improved hardenability and strength properties - **Silicon Range**: Provides deoxidation and solid solution strengthening - **Copper Option**: Available for enhanced corrosion resistance --- #### **3. Physical & Mechanical Properties** **Mechanical Properties (for thicknesses up to 2.5 inches/63 mm):** | Property | Value | |---|---| | **Tensile Strength** | 655-795 MPa (95-115 ksi) | | **Yield Strength (min.)** | 415 MPa (60 ksi) | | **Elongation in 2" (min.)** | 17% | | **Elongation in 8" (min.)** | 19% | **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**: 47.5 W/m·K - **Coefficient of Thermal Expansion**: 11.8 × 10⁻⁶/°C - **Specific Heat Capacity**: 475 J/kg·K --- #### **4. Product Applications** **Heavy Structural Engineering:** - Bridge girders and components - High-rise building structural members - Industrial plant support structures - Crane runway beams **Mining and Construction Equipment:** - Excavator structural components - Mining shovel frames and booms - Heavy equipment structural members - Crane boom sections **Transportation and Infrastructure:** - Railway bridge components - Heavy-haul trailer frames - Port facility structural members - Specialized transportation equipment **Energy and Power Generation:** - Power plant structural supports - Wind turbine tower components - Hydroelectric plant structures - Transmission tower members **Industrial Machinery:** - Heavy press frames - Large machinery structural components - Industrial robot support structures - Specialized equipment bases --- #### **5. Fabrication Characteristics** **Welding Performance:** - **Good Weldability with Precautions**: Requires controlled procedures - **Preheat Requirements**: 250-350°F (120-175°C) based on thickness - **Recommended Processes**: SMAW, GMAW, FCAW with low-hydrogen electrodes - **Filler Metals**: E90XX or E100XX series electrodes **Forming & Machining:** - **Moderate Formability**: Requires adequate power for forming operations - **Bend Radius**: Typically 3t for 90° bends - **Machinability**: Fair to poor (approximately 45% of B1112 steel) - **Cutting Methods**: Plasma, laser, and waterjet cutting preferred **Heat Treatment:** - Supplied in quenched and tempered condition - Maximum hardness: 321 HBW - Consistent through-thickness properties **Quality Assurance:** - Mandatory Charpy V-Notch impact testing - Multiple test locations per plate - Complete mechanical property certification - Non-destructive testing available when specified --- ### **Technical Summary** ASTM A678 Grade B represents an advanced quenched and tempered carbon steel plate that delivers enhanced mechanical properties for demanding structural applications. With a minimum yield strength of 60 ksi, this grade provides significant advantages in weight reduction and structural efficiency compared to conventional structural steels. The controlled heat treatment process ensures superior toughness and consistent mechanical properties throughout the plate thickness. The grade's chemical composition is carefully balanced to provide optimal hardenability while maintaining good weldability characteristics. This makes it particularly valuable for applications in heavy construction, mining equipment, and infrastructure projects where both high strength and impact resistance are critical requirements. The material's certified impact properties and guaranteed mechanical performance provide engineers with reliable data for structural design calculations. While requiring more sophisticated fabrication techniques and strict adherence to welding procedures, ASTM A678 Grade B offers exceptional performance in severe service conditions. Its combination of high strength, good toughness, and reasonable fabrication characteristics has established it as a preferred material for critical structural components where safety, reliability, and longevity are paramount considerations. -:- For detailed product information, please contact sales. -: ASTM A678 Steel, grade B Specification Dimensions Size： Diameter 20-1000 mm Length <4307 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 B Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A678 Steel Sheet,Plate, grade B -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A678 Steel Sheet,Plate, grade B -:- For detailed product information, please contact sales. -:

Packing of ASTM A678 Steel Sheet/Plate, grade B -:- 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 Sheet/Plate 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 778 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