Spherical ASTM A678 Steel Powder, grade A

ASTM A678 Steel Spherical Powder, grade A Product Information -:- For detailed product information, please contact sales. -: ASTM A678 Steel Spherical Powder, grade A Synonyms -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: Spherical ASTM A678 Steel Powder, grade A characteristics -:- For detailed product information, please contact sales. -: Spherical ASTM A678 Steel Powder, grade A Particle Size -:- For detailed product information, please contact sales. -: -:- -:- 0-15μm ,5-25μm, 15-45μm, 15-53μm,20-63um, 45-75μm, 45-105μm, 45-150μm ,75-150μm. (Various granularities can be customized according to customer requirements) -:- For detailed product information, please contact sales. -:

Spherical ASTM A678 Steel Powder, grade A Applicable processes -:- For detailed product information, please contact sales. -: Laser/electron beam additive manufacturing (SLM/EBM, 3D printing) Direct laser deposition (DLD) Used in thermal spray (TSA) Powder hot isostatic pressing (HIP) Metal injection molding (MIM) Powder metallurgy (PM) Laser cladding (LC), etc. -:- For detailed product information, please contact sales. -: Spherical ASTM A678 Steel Powder, grade A Chemical Composition -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: ASTM A678 Steel, grade A Product Information -:- For detailed product information, please contact sales. -: ## **Technical Data Sheet: ASTM A678 Grade A High-Strength Quenched & Tempered Structural Steel Plate** --- ### **1. PRODUCT OVERVIEW** **Standard Designation:** ASTM A678/A678M **Full Title:** Standard Specification for *Quenched-and-Tempered Carbon and Alloy Steel Plates for Structural Applications* **Grade:** A **International Standard:** ASTM International (American Society for Testing and Materials) **Material Classification:** High-strength, quenched and tempered carbon steel plate with enhanced atmospheric corrosion resistance **Primary Feature:** The only grade within A678 specifically noted for improved atmospheric corrosion resistance (approximately 2 times that of carbon steel) --- ### **2. MATERIAL CHARACTERISTICS & MANUFACTURING** ASTM A678 Grade A represents a class of **quenched and tempered (Q&T) structural steel plates** that combine high strength with improved weathering characteristics. Unlike as-rolled steels, Grade A undergoes a precise heat treatment sequence: austenitizing followed by rapid quenching and subsequent tempering. This process produces a tempered martensitic microstructure that delivers an optimal balance of strength, toughness, and weldability. **Key Distinguishing Attributes:** - **Heat-Treated:** Quenching and tempering provide superior property consistency through the plate thickness compared to as-rolled steels. - **Weathering Resistance:** Contains approximately 0.20% Copper (Cu) minimum, enhancing atmospheric corrosion resistance (about 2x better than plain carbon steel). - **Excellent Toughness:** Significantly better notch toughness and impact resistance than non-heat-treated structural steels of similar strength. - **Weldable:** Despite its high strength, it maintains good weldability with proper procedures due to controlled carbon content and microalloying. --- ### **3. CHEMICAL COMPOSITION REQUIREMENTS** The chemical composition is carefully controlled to achieve the desired mechanical properties and atmospheric corrosion resistance. | Element | Composition (% by weight, max unless range is shown) | |---------|------------------------------------------------------| | **Carbon (C)** | 0.15 - 0.21 | | **Manganese (Mn)** | 0.90 - 1.35 | | **Phosphorus (P)** | 0.035 | | **Sulfur (S)** | 0.040 | | **Silicon (Si)** | 0.15 - 0.40 | | **Copper (Cu)** | 0.20 min | | **Nickel (Ni)** | 0.25 max (report only) | | **Chromium (Cr)** | 0.25 max (report only) | | **Molybdenum (Mo)** | 0.08 max (report only) | | **Vanadium (V)** | 0.05 max (report only) | **Carbon Equivalent (CE):** Typically 0.40 - 0.48, calculated per IIW formula: **CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15** --- ### **4. MECHANICAL PROPERTIES** #### **Minimum Required Properties (as per ASTM A678):** - **Yield Strength (0.2% offset):** **50 ksi min (345 MPa min)** - **Tensile Strength:** **70 - 90 ksi (485 - 620 MPa)** - **Elongation in 8-inch gauge length:** **18% min** - **Elongation in 2-inch gauge length:** **21% min** #### **Impact Toughness (Charpy V-Notch):** - **Test Temperature:** +70°F (+21°C) or as specified by purchaser - **Minimum Average Energy:** **15 ft-lbf (20 J)** - **Minimum Individual Value:** **12 ft-lbf (16 J)** #### **Typical Property Range:** - **Yield Strength:** 55 - 65 ksi (typical) - **Tensile Strength:** 75 - 85 ksi (typical) - **Yield-to-Tensile Ratio:** 0.70 - 0.75 - **Hardness:** 200 - 240 HB (Brinell) - **Modulus of Elasticity:** 29,000 ksi (200 GPa) - **Shear Modulus:** 11,500 ksi (79 GPa) #### **Physical Properties:** - **Density:** 0.284 lb/in³ (7,850 kg/m³) - **Poisson's Ratio:** 0.29 - **Coefficient of Thermal Expansion:** 6.5 × 10⁻⁶/°F (11.7 × 10⁻⁶/°C) - **Thermal Conductivity:** 28 Btu·in/(hr·ft²·°F) [45 W/(m·K)] --- ### **5. FABRICATION CHARACTERISTICS** #### **Formability:** - Good formability for bending and rolling operations - Minimum bend radius: Approximately 2.5 × plate thickness (for 90° bend) - Cold forming is possible but may require stress relief for severe deformation #### **Weldability:** - **Good** when using appropriate procedures - Recommended processes: SMAW (stick), GMAW (MIG), FCAW (flux-cored), SAW (submerged arc) - Preheating: Required for thicknesses > 1 inch (25 mm), typically 200-300°F (95-150°C) - Post-weld heat treatment: Generally not required for most applications - Use low-hydrogen electrodes and maintain dry conditions #### **Machinability:** - **Fair to Good** (70% relative to AISI 1212 steel) - Requires positive rake angles and adequate tool rigidity - Recommended cutting speeds: 120-180 SFPM for turning operations #### **Corrosion Performance:** - Atmospheric corrosion resistance approximately 2 times that of plain carbon steel - Forms a protective, adherent rust patina that retards further corrosion - Not suitable for immersion or severe chemical environments without coating --- ### **6. PRIMARY APPLICATIONS** ASTM A678 Grade A is specified for structural applications requiring superior strength, toughness, and moderate weathering resistance without the need for painting in certain environments. #### **Infrastructure & Construction:** - Unpainted bridge components (girders, floor beams, cross-frames) - High-rise building structural members - Transmission tower structural components - Crane runway girders and support structures - Offshore platform walkways and non-critical structures #### **Transportation & Heavy Equipment:** - Railroad car underframes and structural components - Truck trailer main beams and heavy-duty chassis - Mining equipment structural frames - Excavator and crane boom reinforcements - Material handling equipment support structures #### **Industrial & Energy:** - Power plant structural steel (catwalks, platforms, supports) - Conveyor system heavy-duty frames and trusses - Hydraulic press frames and platens - Wind turbine tower internal structural components - Industrial storage rack heavy-duty uprights #### **Special Structures:** - Light poles and high-mast lighting poles (structural elements) - Sporting arena roof support structures - Long-span architectural structural elements - Bridge bearings and expansion joint supports --- ### **7. COMPARATIVE ANALYSIS** #### **Within ASTM A678 Family:** | Property | Grade A | Grade B | Grade C | Grade D | |----------|---------|---------|---------|---------| | **Min Yield (ksi)** | 50 | 60 | 65 | 75 | | **Min Tensile (ksi)** | 70-90 | 80-100 | 90-110 | 100-120 | | **Corrosion Resistance** | 2x (with Cu) | Standard | Standard | Standard | | **Primary Application** | Weathering structures | General structural | High-strength structural | Ultra-high-strength | #### **Competitive/Alternative Materials:** - **ASTM A588:** Similar weathering steel, but as-rolled (not Q&T), slightly lower strength - **ASTM A514:** Quenched & tempered alloy steel, much higher strength (100 ksi yield) - **ASTM A709:** Bridge steel specification with weathering grades (50W, HPS 50W) - **EN 10025-5:** S355J0WP/J2WP (European weathering steel equivalent, lower strength) - **JIS G3114:** SMA (Japanese weathering steel for welded structures) --- ### **8. QUALITY ASSURANCE & TESTING** #### **Certification Requirements:** - Heat analysis report for chemical composition - Mechanical property test reports (tensile, impact) - Heat treatment records (quench & temper cycle parameters) - Ultrasonic testing available as supplementary requirement #### **Standard Testing Methods:** - **Tension Testing:** ASTM A370 (longitudinal specimens) - **Impact Testing:** ASTM A673 (frequency H - every heat) - **Bend Testing:** ASTM E290 (when specified) - **Hardness Testing:** ASTM E10 (Brinell) or E18 (Rockwell) - **Nondestructive Testing:** ASTM A578 (ultrasonic) --- ### **9. DESIGN & SPECIFICATION GUIDELINES** #### **Important Design Considerations:** - Utilize 50 ksi minimum yield strength for all structural calculations - Account for potential distortion during welding; use balanced welding sequences - Consider the weathering steel appearance in architectural applications - For bolted connections, ensure joint design accounts for higher strength #### **Specification Language:** ``` Structural Steel Plate: ASTM A678, Grade A Condition: Quenched and Tempered Thickness: [Specify] inches/mm Width/Length: [Specify] inches/mm Impact Test: Charpy V-notch at +70°F, 15 ft-lbf minimum average Supplementary Requirement: [S1 - Ultrasonic Test, if required] ``` --- ### **10. GLOBAL EQUIVALENTS & CROSS-REFERENCES** #### **International Standard Equivalents:** - **ISO 4950-2:** High yield strength steel plates (approximate equivalent) - **EN 10025-6:** S460Q/QL/QL1 (similar Q&T steel, higher strength) - **JIS G3128:** SGV 480 (high yield strength steel for bridges) - **GB/T 16270:** Q460qD/E (Chinese high strength bridge steel) #### **Related Industry Specifications:** - **AASHTO M222:** Uncoated Weathering Steel (for highway structures) - **AWS D1.5:** Bridge Welding Code (references A678 for qualifying procedures) - **AISC 360:** Steel Construction Manual (references for design) - **API 2H:** Offshore Structural Steel (more stringent requirements) --- ### **11. ENVIRONMENTAL & SUSTAINABILITY** #### **Sustainability Benefits:** - **Reduced Maintenance:** Weathering characteristics can eliminate need for painting in suitable environments - **Long Service Life:** High strength-to-weight ratio reduces material usage - **100% Recyclable:** Can be recycled indefinitely without property degradation - **Lower Lifecycle Cost:** Reduced maintenance and longer service intervals #### **Environmental Considerations:** - Runoff from weathering steel may temporarily discolor surrounding areas - Not recommended for marine or severe industrial environments without protection - Compatible with green building rating systems (LEED, BREEAM) when appropriately applied --- ### **CONCLUSION** ASTM A678 Grade A represents a **versatile high-strength structural steel** that uniquely combines **quenched-and-tempered mechanical properties** with **improved atmospheric corrosion resistance**. Its 50 ksi minimum yield strength, excellent toughness, and weathering characteristics make it particularly valuable for bridges, architectural structures, and heavy equipment where durability and reduced maintenance are priorities. The steel's heat-treated condition ensures uniform properties through the plate thickness, providing design reliability for critical structural applications. While offering good weldability, proper procedures must be followed to maintain the heat-affected zone properties. When specifying A678 Grade A, engineers benefit from: 1. **Certified mechanical properties** through full heat treatment 2. **Enhanced corrosion resistance** without alloying to A588 levels 3. **Superior toughness** compared to as-rolled steels of similar strength 4. **Proven performance** in structural applications for over 50 years This material is optimally specified when the application requires strength between conventional structural steel and ultra-high-strength Q&T alloys, with the added benefit of weathering resistance for suitable environments. --- *This technical data is based on the current ASTM A678/A678M-19 standard. Always consult the latest edition of the specification and mill test reports for critical applications.* -:- For detailed product information, please contact sales. -: ASTM A678 Steel, grade A Specification Dimensions Size： Diameter 20-1000 mm Length <5948 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. -:

Spherical ASTM A678 Steel Powder, grade A Particle Size Description -:- For detailed product information, please contact sales. -: Applications of Spherical ASTM A678 Steel Powder, grade A -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: Applications of ASTM A678 Steel Spherical Powder, grade A -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A678 Steel Spherical Powder, grade A -:- For detailed product information, please contact sales. -:

Packing of ASTM A678 Steel Spherical Powder, 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 Spherical Powder 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 2419 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