NUCu Steel - ASTM A710 Grade B

NUCu Steel - ASTM A710 Grade B Product Information -:- For detailed product information, please contact sales. -: NUCu Steel - ASTM A710 Grade B Synonyms -:- For detailed product information, please contact sales. -:

NUCu Steel - ASTM A710 Grade B Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: ASTM A710 Grade B (NUCu) Low-Carbon Precipitation-Hardening Steel** **ASTM A710 Grade B**, commonly referred to as **NUCu Steel**, is an advanced **low-carbon, copper-precipitation-hardened alloy steel** designed for **welded structures requiring an exceptional combination of high strength, excellent toughness, and superior atmospheric corrosion resistance**. Unlike conventional HSLA steels, NUCu steel derives its primary strength from the precipitation of fine, coherent copper-rich particles during a controlled **aging heat treatment**. This unique mechanism allows it to achieve **high yield strengths (typically 70-100 ksi / 485-690 MPa) while maintaining an extremely low carbon content (<0.07%)**, resulting in unparalleled weldability and notch toughness, even in thick sections. It is often specified for critical applications in **bridge construction, offshore platforms, pressure vessels, and military vehicles**. --- ## **International Standard & Key Specifications** * **Primary Standard:** **ASTM A710/A710M** - Standard Specification for Precipitation-Strengthened Low-Carbon Nickel-Copper-Chromium-Molybdenum-Columbium Alloy Structural Steel Plates. * **Key Distinction:** The specification defines steels that gain strength primarily from **precipitation hardening (aging)**, not from carbon content or conventional heat treatment like quenching. * **ASME Code Equivalent:** **SA-710/SA-710M** in ASME Boiler and Pressure Vessel Code, Section II, Part A, for pressure equipment. * **Related Specifications:** * **ASTM A20/A20M** - General Requirements for Steel Plates. * **ASTM A770** - Through-Thickness Tension Testing (often specified for thick plates). * **MIL-S-24645A (SH)** - Military specification for HSLA-100 steel, a related naval application. * **Common Tempers:** Supplied in different heat-treated conditions (e.g., **Class 1: Aged; Class 3: Quenched & Aged**) to achieve various strength-toughness combinations. --- ## **Chemical Composition (Weight %, max unless range is specified) - Grade B** The hallmark of NUCu steel is its ultra-low carbon, high-copper, nickel-alloyed composition designed for precipitation hardening. | Element | Composition (%) | Role in Performance | | :--- | :--- | :--- | | **Carbon (C)** | **0.07 max** | **Ultra-low.** The defining feature, ensuring exceptional weldability and base metal toughness. Shifts strengthening to precipitation. | | **Manganese (Mn)** | 0.40 - 0.70 | Solid solution strengthener, aids in sulfide shape control. | | **Phosphorus (P)** | 0.025 max | Impurity, kept very low. | | **Sulfur (S)** | 0.025 max | Impurity, tightly controlled for Z-direction ductility. | | **Silicon (Si)** | 0.15 - 0.50 | Deoxidizer. | | **Nickel (Ni)** | 0.70 - 1.00 | Enhances hardenability, low-temperature toughness, and complements copper's corrosion resistance. | | **Copper (Cu)** | **1.00 - 1.30** | **Primary precipitation-hardening element.** Forms nano-scale Cu-rich precipitates during aging, providing major strength increase. | | **Chromium (Cr)** | 0.40 - 0.65 | Improves atmospheric corrosion resistance and hardenability. | | **Molybdenum (Mo)** | 0.15 - 0.25 | Enhances hardenability and strength, particularly at elevated temperatures; reduces temper embrittlement risk. | | **Columbium (Cb/Nb)** | 0.02 - 0.10 | **Critical microalloy.** Provides grain refinement and additional precipitation strengthening via Nb(CN). | | **Vanadium (V)** | 0.03 - 0.08 | Optional microalloy for additional precipitation strengthening. | | **Aluminum (Al)** | 0.06 max | Grain refining deoxidizer. | | **Carbon Equivalent (CE)** | **Typically ≤ 0.40** | Extremely low, indicating excellent weldability. | --- ## **Typical Physical & Mechanical Properties** Properties depend on the specific class (heat treatment). **Grade B** typically corresponds to a yield strength of **70 ksi (485 MPa) minimum** in the aged condition (Class 1). | Property | Value / Description (Class 1 - Aged) | | :--- | :--- | | **Tensile Strength** | 585 - 725 MPa (85,000 - 105,000 psi) | | **Yield Strength (min)** | **485 MPa (70,000 psi)** | | **Elongation in 2-in (50 mm) (min)** | 20% | | **Reduction of Area (min)** | 50% | | **Modulus of Elasticity** | ~200 GPa (29 x 10⁶ psi) | | **Density** | ~7.85 g/cm³ | | **Charpy V-Notch Impact Toughness** | **Test Temperature:** **-100°F (-73°C)**. **Minimum Avg.:** **35 ft·lbf (48 J)**. *Exceptional toughness at cryogenic temperatures is a key advantage.* | | **Atmospheric Corrosion Resistance** | **4-6 times** greater than carbon steel (due to Cu, Ni, Cr content), functioning as a weathering steel. | | **Through-Thickness (Z-Direction) Ductility** | Excellent due to very low sulfur content; often exceeds 40% Reduction of Area in ASTM A770 tests. | | **Weldability (Pcm)** | **Pcm typically < 0.20**. Can often be welded **without preheat**, even in thick sections. | --- ## **Product Applications** NUCu (A710 Grade B) steel is specified for the most demanding structural and containment applications where weight savings, fabrication efficiency, and extreme environment performance are critical. **Primary Industries and Structures:** 1. **Advanced Bridge Construction:** * **Fracture-critical members** in long-span bridges. * **Components** for bridges in severe cold climates or coastal environments. 2. **Naval & Offshore Marine:** * **Hull structures** for naval ships (e.g., U.S. Navy's HSLA-100 is a derivative). * **Critical nodes and braces** in offshore oil & gas platforms. 3. **Pressure Vessels & Energy:** * **High-pressure vessels** for hydrogen storage and transportation. * **Cryogenic storage tanks** (LNG, industrial gases). * **Components in nuclear power plants**. 4. **Military & Aerospace:** * **Armored vehicle hulls** and structural components. * **Launch support structures** and missile components. 5. **Heavy Construction Equipment:** * **Booms and frames** for high-capacity cranes and excavators. --- ## **Advantages and Critical Fabrication Considerations** * **Advantages:** * **Unmatched Weldability:** The ultra-low carbon content allows welding **with little or no preheat**, drastically reducing fabrication cost, time, and distortion. * **Exceptional Toughness:** Maintains high impact energy down to cryogenic temperatures (-100°F). * **High Strength-to-Weight Ratio:** Enables lighter, more efficient designs. * **Excellent Corrosion Resistance:** Functions as a high-performance weathering steel. * **Resistance to Lamellar Tearing:** Superior Z-direction properties due to low S and fine microstructure. * **Critical Fabrication Considerations:** * **Heat Treatment Sensitivity:** Final properties are achieved through a **precise aging treatment**. Fabrication processes (e.g., welding, thermal cutting) must not expose the material to temperatures that would **over-age** (typically >1150°F / 620°C) and cause softening. A **post-weld aging** treatment may be required to restore full strength in the HAZ. * **Welding Procedure:** Although weldable without preheat, **low-hydrogen practices are still mandatory**. Filler metal selection is critical; Ni-Cu alloyed consumables are often used to match corrosion resistance and toughness. * **Thermal Cutting:** Plasma or laser cutting is preferred. If flame cutting is used, preheat is recommended to avoid hydrogen pickup, despite the low CE. * **Higher Material Cost:** The advanced alloying and processing result in a premium material cost, justified by lifecycle and fabrication savings. **In summary, ASTM A710 Grade B (NUCu) steel represents a paradigm shift in structural steel technology. By decoupling strength from carbon content, it achieves a previously unattainable synergy of ultra-high strength, outstanding toughness, and phenomenal weldability. It is the material of choice for engineers designing the next generation of safer, lighter, and more durable critical infrastructure under the most challenging environmental and loading conditions.** -:- For detailed product information, please contact sales. -: NUCu Steel - ASTM A710 Grade B Specification Dimensions Size： Diameter 20-1000 mm Length <4553 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. -: NUCu Steel - ASTM A710 Grade B Properties -:- For detailed product information, please contact sales. -:

Applications of NUCu Steel - ASTM A710 Grade B -:- For detailed product information, please contact sales. -: Chemical Identifiers NUCu Steel - ASTM A710 Grade B -:- For detailed product information, please contact sales. -:

Packing of NUCu Steel - ASTM A710 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 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 1024 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