ASTM A678 Steel Tube,Pipe, grade C

ASTM A678 Steel Tube, grade C Product Information -:- For detailed product information, please contact sales. -: ASTM A678 Steel Tube, grade C Synonyms -:- For detailed product information, please contact sales. -:

ASTM A678 Steel, grade C Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: ASTM A678 Grade C Steel** **ASTM A678 Grade C** is a premium high-strength quenched and tempered carbon steel plate designed for the most demanding structural applications. Representing one of the highest strength levels in the A678 specification, Grade C delivers exceptional mechanical properties combined with reliable toughness, making it suitable for critical components where maximum strength-to-weight ratio and structural efficiency are paramount. --- #### **1. International Standards & Grades** **Primary Standard:** **ASTM A678/A678M** - "Standard Specification for Quenched-and-Tempered Carbon Steel Plates for Structural Applications" **Grade Classification:** - **Grade C** - Minimum yield strength 70 ksi (485 MPa) - Other grades in A678 series: A, B, D **International Equivalents:** - **EN 10025-6**: S620Q/S620QL - **JIS G3106**: SM570 - **GB/T 16270**: Q620 - **ISO 4950-3**: EQ620 --- #### **2. Chemical Composition** The chemical composition requirements for ASTM A678 Grade C: | Element | Composition (Maximum %) | |---|---| | Carbon (C) | 0.25 | | Manganese (Mn) | 1.20-1.60 | | Phosphorus (P) | 0.035 | | Sulfur (S) | 0.040 | | Silicon (Si) | 0.15-0.50 | | Copper (Cu) | 0.35 (when specified) | **Key Composition Features:** - **Elevated Carbon Content**: Provides maximum strength capabilities - **High Manganese Range**: Ensures deep hardenability and strength - **Optimized Silicon**: Enhances strength and oxidation resistance - **Copper Addition**: Optional for improved corrosion performance --- #### **3. Physical & Mechanical Properties** **Mechanical Properties (for thicknesses up to 2.5 inches/63 mm):** | Property | Value | |---|---| | **Tensile Strength** | 760-895 MPa (110-130 ksi) | | **Yield Strength (min.)** | 485 MPa (70 ksi) | | **Elongation in 2" (min.)** | 16% | | **Elongation in 8" (min.)** | 18% | **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**: 46.5 W/m·K - **Coefficient of Thermal Expansion**: 11.9 × 10⁻⁶/°C - **Specific Heat Capacity**: 470 J/kg·K --- #### **4. Product Applications** **Critical Structural Components:** - Bridge tension members - High-rise building structural elements - Long-span roof structures - Seismic-resistant construction **Heavy Mining Equipment:** - Excavator boom and arm sections - Mining shovel structural components - Dragline machine members - Crusher frame structures **Energy Infrastructure:** - Wind turbine tower flanges - Power plant critical supports - Hydroelectric dam components - Nuclear plant structural members **Transportation Systems:** - Railway bridge compression members - Heavy-haul vehicle frames - Port crane structural components - Specialized transport equipment **Industrial Machinery:** - Heavy press frames and platens - Large machine tool structures - Industrial robot base frames - Specialized equipment supports --- #### **5. Fabrication Characteristics** **Welding Performance:** - **Fair Weldability**: Requires strict procedure control - **Preheat Requirements**: 300-400°F (150-200°C) minimum - **Recommended Processes**: SMAW, GMAW, FCAW (low-hydrogen only) - **Filler Metals**: E110XX or E120XX series electrodes **Forming & Machining:** - **Limited Formability**: Restricted to simple bending operations - **Minimum Bend Radius**: 3.5t for 90° bends - **Machinability**: Poor (approximately 40% of B1112 steel) - **Cutting Methods**: Waterjet and laser cutting recommended **Heat Treatment:** - Supplied in quenched and tempered condition - Maximum hardness: 341 HBW - Through-thickness property consistency verified **Quality Assurance:** - Mandatory Charpy V-Notch impact testing - Multiple test locations through thickness - Complete mechanical property certification - Ultrasonic testing available when specified --- ### **Technical Summary** ASTM A678 Grade C represents the pinnacle of quenched and tempered carbon steel plate technology, offering exceptional strength characteristics for the most demanding structural applications. With a minimum yield strength of 70 ksi, this grade provides maximum weight reduction potential while maintaining structural integrity under extreme loading conditions. The advanced heat treatment process ensures optimal combination of high strength and adequate toughness, making Grade C particularly valuable for applications where material efficiency and performance under stress are critical. The carefully controlled chemical composition provides the necessary hardenability while maintaining reasonable weldability with proper procedures. This premium grade is specifically engineered for critical infrastructure projects, heavy mining equipment, and advanced energy applications where failure is not an option. While requiring sophisticated fabrication techniques and rigorous quality control, ASTM A678 Grade C delivers unmatched performance in severe service conditions, establishing it as the material of choice for engineers designing next-generation structural systems where safety, reliability, and performance are paramount considerations. -:- For detailed product information, please contact sales. -: ASTM A678 Steel, grade C Specification Dimensions Size： Diameter 20-1000 mm Length <4308 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 C Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A678 Steel Tube, grade C -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A678 Steel Tube, grade C -:- For detailed product information, please contact sales. -:

Packing of ASTM A678 Steel Tube, grade C -:- 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 779 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