Bethlehem Steel Rod/Bar RQC ASTM A678 RQC60 Q&T, Steel Rod/Bar

Bethlehem Steel Rod RQC ASTM A678 RQC60 Q&T 3/16 to 1-1/2 in. thick, Steel Rod plate Product Information -:- For detailed product information, please contact sales. -: Bethlehem Steel Rod RQC ASTM A678 RQC60 Q&T 3/16 to 1-1/2 in. thick, Steel Rod plate Synonyms -:- For detailed product information, please contact sales. -:

Bethlehem Steel RQC ASTM A678 RQC60 Q&T 3/16 to 1-1/2 in. thick, steel plate Product Information -:- For detailed product information, please contact sales. -: ## **Product Datasheet: Bethlehem Steel RQC (Rapid Quenched Carbon) ASTM A678 RQC60 Steel Plate** **Product Overview** Bethlehem Steel RQC ASTM A678 RQC60 is a proprietary quenched and tempered (Q&T) carbon-manganese structural steel plate representing a unique subset of the ASTM A678 family. The **RQC (Rapid Quenched Carbon)** designation signifies Bethlehem Steel's optimized manufacturing approach for achieving a fine-grained, high-toughness tempered martensitic structure with a leaner alloy design than traditional high-strength Q&T steels. Engineered to provide an excellent balance of **60 ksi minimum yield strength**, superior low-temperature toughness, and good weldability, RQC60 was designed for applications demanding high fracture resistance without the need for heavy alloying. 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 & Specifications** * **Primary Standard:** **ASTM A678 / A678M** - Standard Specification for Quenched-and-Tempered Carbon and High-Strength Low-Alloy Structural Steel Plate. * **Governing Specification:** The "RQC60" designation indicates this product is supplied to meet the mechanical and toughness requirements of a **60 ksi minimum yield strength quenched and tempered plate**, fully conforming to the spirit and requirements of ASTM A678 for such a grade, though "RQC60" itself is a proprietary Bethlehem Steel nomenclature. * **Core Supplementary Requirement:** This product was inherently produced to meet stringent impact test requirements, aligning with: * **ASTM A6 Supplementary Requirement S1 (Charpy V-Notch Impact Testing):** Typically certified at low temperatures (e.g., -50°F / -46°C). * **Industry Context:** Often specified in lieu of ASTM A633 Grade E or where the toughness of ASTM A537 Class 1 was required but at a higher strength level. It bridges the gap between normalized HSLA and more highly alloyed Q&T steels. **Chemical Composition (Weight % - Typical RQC60 Range)** The RQC chemistry emphasizes a lean, clean carbon-manganese base with microalloying for grain control, minimizing costly alloying elements like nickel and molybdenum. | Element | Typical RQC60 Aim / Range | Key Purpose | | :--- | :--- | :--- | | **Carbon (C)** | 0.14 - 0.20% | Lower carbon for excellent weldability and toughness. | | **Manganese (Mn)** | 1.00 - 1.40% | Primary strengthening and hardenability agent. | | **Phosphorus (P)** | ≤ 0.020% | Impurity control. | | **Sulfur (S)** | ≤ 0.010% | Low sulfur for improved toughness and through-thickness properties. | | **Silicon (Si)** | 0.15 - 0.35% | Deoxidizer and solid solution strengthener. | | **Aluminum (Al)** | 0.02 - 0.06% | Grain refiner (fine grain practice). | | **Niobium (Nb) / Vanadium (V)** | 0.02 - 0.05% (either or both) | Grain refinement and precipitation strengthening. | | **Nitrogen (N)** | Controlled | Optimized for microalloy carbonitride formation. | | **Carbon Equivalent (C.E. IIW)** | Typically 0.38 - 0.45 | Very favorable, indicating excellent weldability for a Q&T steel. | **Physical & Mechanical Properties** | Property | RQC60 Minimum/Target Requirement | Typical Performance | | :--- | :--- | :--- | | **Yield Strength (Min)** | 60 ksi (415 MPa) | 65 - 75 ksi (448 - 517 MPa) | | **Tensile Strength** | 80 - 100 ksi (550 - 690 MPa) | 85 - 95 ksi (586 - 655 MPa) | | **Elongation in 2" (Min)** | 20% | 22 - 28% | | **Yield-to-Tensile Ratio** | -- | Typically 0.75 - 0.82 | | **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) | | **Charpy V-Notch Toughness (Hallmark)** | **High (e.g., 40-60 ft-lb @ -50°F / -46°C)** | Exceptional low-temperature toughness is the defining characteristic of the RQC series, often exceeding standard A678 Grade B requirements. | | **Key Feature** | **Lean-Alloy High Toughness:** Achieves remarkable fracture resistance (high Charpy values) at -50°F through optimized rapid quenching and tempering of a clean, fine-grained carbon-manganese steel, rather than heavy nickel/chromium additions. | **Product Applications** Bethlehem Steel RQC60 was specified for critical structural applications where low-temperature toughness and fatigue resistance were primary design concerns, often in harsh environments. * **Building & Bridge Construction:** Fracture-critical members in bridges, seismic-resistant moment frame connections, and structures in cold climates (e.g., Alaska, Northern Canada). * **Offshore & Marine Structures:** Node connections and critical weldments in offshore oil & gas platforms and ice-strengthened vessel components. * **Mining & Heavy Equipment:** Boom and arm sections for excavators operating in arctic conditions, and components for mining equipment where impact loading is a concern. * **Pressure Vessel & Storage:** For low-temperature liquid storage tanks (LNG, ethylene) where ASTM A537 Class 1 toughness is required but higher strength is beneficial. * **Power Generation:** Penstocks and other components for hydroelectric plants in cold regions. **Advantages & Fabrication Notes** * **Exceptional Weldability:** Its low carbon equivalent (often below 0.45) makes RQC60 one of the most weldable quenched and tempered steels available. It requires standard low-hydrogen practices but with lower preheat requirements than higher-CE Q&T grades. * **Superior Toughness-to-Strength Ratio:** The primary design advantage. It provides Charpy impact values typically associated with much lower strength steels, offering a large safety margin against brittle fracture. * **Cost-Effectiveness:** The lean alloy design, avoiding significant nickel and molybdenum, made it a cost-competitive option for achieving high toughness in a Q&T plate. * **Good Formability:** Can be cold formed with appropriate bend radii due to its good ductility and lower yield ratio. * **Legacy Product Note:** RQC was a proprietary Bethlehem Steel product line. Modern equivalents include proprietary **"ToughMet"** or **"HSLA QT"** grades from other producers, or specified plates meeting ASTM A678 Grade B chemistry with enhanced, guaranteed impact properties. **Disclaimer:** This datasheet describes the historical **Bethlehem Steel RQC60** product. "RQC60" is not a current ASTM designation. For current projects requiring similar performance, engineers should specify the required mechanical properties (**60 ksi min YS, 80-100 ksi UTS**) and, crucially, the **Charpy V-Notch impact energy at the required service temperature** (e.g., **40 ft-lb min @ -50°F**). Modern steel producers can supply quenched and tempered plates meeting these criteria, often under proprietary brand names or as a custom melt to ASTM A678. Always request and review the Mill Test Certificate for actual chemistry, mechanical properties, and impact test data. -:- For detailed product information, please contact sales. -: Bethlehem Steel RQC ASTM A678 RQC60 Q&T 3/16 to 1-1/2 in. thick, steel plate Specification Dimensions Size： Diameter 20-1000 mm Length <4669 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 RQC ASTM A678 RQC60 Q&T 3/16 to 1-1/2 in. thick, steel plate Properties -:- For detailed product information, please contact sales. -:

Applications of Bethlehem Steel Rod RQC ASTM A678 RQC60 Q&T 3/16 to 1-1/2 in. thick, Steel Rod plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Bethlehem Steel Rod RQC ASTM A678 RQC60 Q&T 3/16 to 1-1/2 in. thick, Steel Rod plate -:- For detailed product information, please contact sales. -:

Packing of Bethlehem Steel Rod RQC ASTM A678 RQC60 Q&T 3/16 to 1-1/2 in. thick, Steel Rod 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 Rod 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 1140 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