Bethlehem Steel Seamless tube ASTM A678, Steel Seamless tube

Bethlehem Steel Seamless tube ASTM A678 Grade A 3/16 to 1-1/2 in. thick, Steel Seamless tube plate Product Information -:- For detailed product information, please contact sales. -: Bethlehem Steel Seamless tube ASTM A678 Grade A 3/16 to 1-1/2 in. thick, Steel Seamless tube plate Synonyms -:- For detailed product information, please contact sales. -:

Bethlehem Steel ASTM A678 Grade A 3/16 to 1-1/2 in. thick, steel plate Product Information -:- For detailed product information, please contact sales. -: ## **Product Datasheet: Bethlehem Steel ASTM A678 Grade A Steel Plate** **Product Overview** Bethlehem Steel ASTM A678 Grade A is a high-strength, low-alloy (HSLA) structural steel plate produced by **quenching and tempering (Q&T) heat treatment**. This manufacturing process involves austenitizing, water quenching, and subsequent tempering, which yields a fine-grained, tempered martensite or bainitic microstructure. This structure provides an exceptional balance of high strength, excellent toughness, and superior weldability compared to as-rolled or normalized steels of similar strength levels. This plate is available in thicknesses ranging from **3/16 inch (4.8 mm) to 1-1/2 inches (38.1 mm)**. **Key International Standards** * **Primary Standard:** **ASTM A678 / A678M** - Standard Specification for Quenched-and-Tempered Carbon and High-Strength Low-Alloy Structural Steel Plate. * **Governing Specification:** This product strictly conforms to all requirements for **Grade A** as defined in ASTM A678. Grade A is one of the lower-strength grades within the A678 family, designed for applications requiring improved toughness and formability alongside enhanced strength. * **Additional Standards:** It may also be specified to meet supplementary requirements from ASTM A6, such as impact testing (S1) or ultrasonic examination (S7). **Chemical Composition (Weight % - ASTM A678 Grade A Requirements & Typical Range)** The chemistry is carefully controlled to ensure proper hardenability during quenching and to develop the desired tempered microstructure without compromising weldability. | Element | ASTM A678 Grade A Requirement (Max, unless noted) | Typical Bethlehem Steel Production Range | | :--- | :--- | :--- | | **Carbon (C)** | 0.23% | 0.18 - 0.22% | | **Manganese (Mn)** | 1.50% | 1.00 - 1.40% | | **Phosphorus (P)** | 0.035% | ≤ 0.025% | | **Sulfur (S)** | 0.05% | ≤ 0.025% | | **Silicon (Si)** | 0.15 - 0.50% | 0.15 - 0.30% | | **Copper (Cu)** | 0.20% Min (when specified) | 0.20 - 0.35% (for atmospheric corrosion resistance) | | **Nickel (Ni)** | -- | May be added in small amounts (e.g., 0.25% max) for toughness | | **Chromium (Cr)** | -- | May be added in small amounts (e.g., 0.25% max) for hardenability | | **Molybdenum (Mo)** | -- | May be added in small amounts (e.g., 0.08% max) for hardenability | | **Vanadium (V)** | -- | May be added (e.g., 0.08% max) for grain refinement | | **Carbon Equivalent (C.E. IIW)** | Not specified in standard | Typically 0.40 - 0.48 (favorable for Q&T steel) | **Physical & Mechanical Properties (ASTM A678 Grade A Requirements)** | Property | Requirement for Grade A | Typical Performance / Notes | | :--- | :--- | :--- | | **Yield Strength (Min)** | 50 ksi (345 MPa) | Typically 55 - 65 ksi (380 - 450 MPa) | | **Tensile Strength** | 70 - 90 ksi (485 - 620 MPa) | Typically 75 - 85 ksi (517 - 586 MPa) | | **Elongation in 2" (Min)** | 22% (for plates ≤ 3/4") | Often exceeds minimum, typically 24-28% | | **Elongation in 8" (Min)** | 18% (for plates ≤ 3/4") | -- | | **Modulus of Elasticity** | ~29,000 ksi (200 GPa) | ~29,000 ksi (200 GPa) | | **Density** | 0.284 lb/in³ (7.85 g/cm³) | 0.284 lb/in³ (7.85 g/cm³) | | **Key Feature** | **Quenched & Tempered Microstructure:** Provides a superior combination of strength and toughness, with a more uniform hardness profile through the thickness compared to as-rolled plates. Excellent low-temperature impact resistance is a hallmark of Q&T steels. | | **Product Applications** The unique properties of ASTM A678 Grade A Q&T plate made it suitable for demanding applications where reliability under dynamic or impact loading is critical. * **Structural Engineering:** Welded bridges, especially fracture-critical members, building columns in seismic zones, and offshore platform nodes. * **Heavy Equipment & Mining:** Key components for excavator arms, loader booms, and mining shovel dippers where resistance to shock and abrasion is needed. * **Material Handling:** Crane runways, trolley frames, and heavy-duty forklift masts subjected to cyclic loading. * **Pressure Vessels & Storage Tanks:** For applications requiring higher strength than standard carbon steel with certified impact properties. * **Military & Defense:** Structural components in vehicles and equipment where ballistic or blast resistance is a consideration. **Advantages & Fabrication Notes** * **Exceptional Toughness:** The Q&T process yields excellent notch toughness and resistance to brittle fracture, often meeting stringent Charpy V-Notch requirements at low temperatures (e.g., -50°F / -46°C). * **Good Weldability:** Despite its high strength, the relatively low carbon content and lean alloy design result in a moderate carbon equivalent. However, strict low-hydrogen welding practices and proper preheat/interpass temperature control are **essential** to preserve the heat-affected zone (HAZ) properties. * **Uniform Properties:** The through-thickness mechanical properties are more consistent than in as-rolled plates, with less strength drop-off in the center of thick sections. * **Formability:** Can be cold formed, but bending radii should be larger than for lower-strength steels to avoid cracking. Hot forming is possible but requires re-quenching and tempering to restore properties. * **Legacy Product Note:** Bethlehem Steel was a significant producer of A678 plate. Modern Q&T steels meeting ASTM A678 Grade A are readily available from contemporary steel mills. **Disclaimer:** This datasheet is based on historical data for **Bethlehem Steel Corporation’s** product conforming to **ASTM A678 Grade A**. For current procurement, specify the active **ASTM A678 Grade A** standard along with any required supplementary conditions (e.g., impact testing temperature). Source material from modern producers who can provide current Mill Test Certificates that include heat treatment records and certified mechanical properties. Always follow the steel producer’s recommended welding and fabrication procedures. -:- For detailed product information, please contact sales. -: Bethlehem Steel ASTM A678 Grade A 3/16 to 1-1/2 in. thick, steel plate Specification Dimensions Size： Diameter 20-1000 mm Length <4662 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. -: Bethlehem Steel ASTM A678 Grade A 3/16 to 1-1/2 in. thick, steel plate Properties -:- For detailed product information, please contact sales. -:

Applications of Bethlehem Steel Seamless tube ASTM A678 Grade A 3/16 to 1-1/2 in. thick, Steel Seamless tube plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Bethlehem Steel Seamless tube ASTM A678 Grade A 3/16 to 1-1/2 in. thick, Steel Seamless tube plate -:- For detailed product information, please contact sales. -:

Packing of Bethlehem Steel Seamless tube ASTM A678 Grade A 3/16 to 1-1/2 in. thick, Steel Seamless tube plate -:- 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 1133 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