ASTM A852 Steel

ASTM A852 Steel Product Information -:- For detailed product information, please contact sales. -: ASTM A852 Steel Synonyms -:- For detailed product information, please contact sales. -:

ASTM A852 Steel Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: ASTM A852/A852M High-Strength Low-Alloy Structural Steel** **ASTM A852/A852M** is a premium **high-strength, low-alloy (HSLA) structural steel** designed for **welded bridges, buildings, and other structures requiring a combination of high strength, excellent atmospheric corrosion resistance, and enhanced toughness at low temperatures**. As a **weathering steel**, it develops a dense, adherent protective rust patina when exposed to the atmosphere, offering **corrosion resistance approximately four to six times greater than that of conventional carbon steels**. This steel is distinguished by its **70 ksi (485 MPa) minimum yield strength** and its **mandatory toughness requirements at -40°F (-40°C)**, making it suitable for fracture-critical members in severe environments. It is typically supplied in the **as-rolled or normalized condition**. --- ## **International Standard & Key Specifications** * **Primary Standard:** **ASTM A852/A852M** - Standard Specification for Quenched and Tempered Low-Alloy Structural Steel Plate with 70 ksi (485 MPa) Minimum Yield Strength to 4 in. (100 mm) Thick. * **Important Note:** The standard title references "quenched and tempered," but the specification explicitly **allows for as-rolled or normalized supply** for thicknesses up to 2 inches (50 mm) unless otherwise specified. For plates over 2 inches, quenching and tempering is typical to achieve the required properties. * **Key Related Standards:** * **ASTM A709/A709M** - Structural Steel for Bridges (Grade 70W is the direct equivalent). * **AASHTO M270M/M270** - For bridge construction (Grade 70W). * **ASTM A6/A6M** - General Requirements for Rolled Structural Steel. * **AWS D1.1/D1.5** - Structural Welding Code. * **Governing Requirement:** **ASTM A841** may be referenced for plates produced by the Thermo-Mechanical Control Process (TMCP), but A852 is the defining specification for chemistry and mechanical properties. --- ## **Chemical Composition (Weight %, max unless range is specified)** The composition is optimized to provide both high strength and the classic weathering steel corrosion resistance through a balanced copper-nickel-chromium system. | Element | Composition (%) | Role in Performance | | :--- | :--- | :--- | | **Carbon (C)** | 0.19 max | Provides base strength while maintaining weldability. | | **Manganese (Mn)** | 0.80 - 1.35 | Primary solid-solution strengthener, enhances hardenability. | | **Phosphorus (P)** | 0.04 max | Contributes to atmospheric corrosion resistance. | | **Sulfur (S)** | 0.05 max | Impurity, controlled for improved ductility. | | **Silicon (Si)** | 0.15 - 0.50 | Deoxidizer and strengthener. | | **Copper (Cu)** | **0.20 - 0.40** | **Essential weathering element.** Initiates and stabilizes the protective patina. | | **Nickel (Ni)** | **0.25 - 0.50** | Enhances toughness and complements the corrosion resistance of Cu. | | **Chromium (Cr)** | **0.40 - 0.70** | Enhances corrosion resistance by forming a dense, stable oxide layer. | | **Vanadium (V)** | 0.01 - 0.10 | Microalloy for grain refinement and precipitation strengthening. | | **Columbium (Cb/Nb)** | 0.005 - 0.05 | Optional microalloy for grain refinement. | **Key Distinction:** The specific combination and minimums of **Cu, Ni, and Cr** qualify it as a weathering steel (denoted by the **"W"** suffix in related specs like A709-70W). --- ## **Typical Physical & Mechanical Properties** Properties must be met regardless of the supply condition (as-rolled, normalized, or quenched and tempered). | Property | Value / Description | | :--- | :--- | | **Tensile Strength** | 620 - 760 MPa (90,000 - 110,000 psi) | | **Yield Strength (min)** | **485 MPa (70,000 psi)** | | **Elongation in 2-in (50 mm) (min)** | 18% | | **Modulus of Elasticity** | ~200 GPa (29 x 10⁶ psi) | | **Density** | ~7.85 g/cm³ (0.284 lb/in³) | | **Charpy V-Notch Impact Toughness** | **Test Temperature:** **-40°F (-40°C)**. **Minimum Avg. for 3 Specimens:** **25 ft·lbf (34 J)**. This is a **mandatory requirement** for all material. | | **Atmospheric Corrosion Resistance** | Approximately **4-6 times** greater than plain carbon steel. | | **Brinell Hardness (typical)** | 200 - 250 HBW (as-rolled/normalized) | --- ## **Product Applications** ASTM A852 (A709-70W) is specified for the most demanding structural applications where high strength, low-temperature toughness, and long-term, low-maintenance durability converge. **Primary Structural Applications:** 1. **Long-Span & Fracture-Critical Bridges:** * **Tension members, chords, and main girders** in major truss, arch, and cable-stayed bridges. * **Fracture-critical members** where guaranteed toughness at -40°F is essential for safety. * **Bridge components** in cold climate regions. 2. **High-Rise & Signature Structures:** * **Exposed primary structural frames** in buildings where the weathering patina is an architectural feature. * **Long-span transfer girders** and **heavy columns**. * **Monuments** and **large-scale art installations**. 3. **Heavy Industrial & Infrastructure:** * **Unpainted crane runway girders** for heavy industry. * **Power transmission towers** in corrosive environments. * **Supporting structures** in aggressive atmospheric conditions (coastal, industrial). --- ## **Advantages and Critical Fabrication & Design Considerations** * **Advantages:** * **High Strength with Weathering Durability:** 70 ksi yield strength combined with proven atmospheric corrosion resistance. * **Excellent Low-Temperature Toughness:** Mandatory impact properties at -40°F ensure reliability in harsh climates and under dynamic loading. * **Lifecycle Cost Savings:** Eliminates painting and maintenance, offering significant savings over the structure's life. * **Aesthetic Value:** Develops a rich, stable patina that is architecturally desirable. * **Critical Fabrication & Design Considerations:** * **Welding Demands:** Higher strength and alloy content require **strict low-hydrogen welding procedures**. Use of weathering-grade filler metals (e.g., E8018-W) is recommended for exposed welds to promote patina matching. Preheat is often required. * **Imperative Detailing:** **Design must ensure complete drainage and ventilation.** Moisture traps are the primary cause of failure. Details like drip edges, seal welds (vs. stitch welds), and drainage holes are crucial. * **Initial Runoff Management:** The patina formation process (1-3 years) produces rust-stained runoff. Design should incorporate features to manage this (overhangs, gutters, sacrificial staining zones). * **Not for Continuous Immersion:** The protective mechanism requires wet/dry cycles. It is **unsuitable** for buried service, constantly submerged areas, or applications with frequent saltwater splash without special design. * **Connection Compatibility:** Fasteners and connections should use weathering steel or be properly isolated from dissimilar metals to prevent galvanic corrosion. * **Fracture Control Plan:** For fracture-critical applications (like bridges), a detailed fracture control plan is often required, which may include stricter inspection criteria. **In summary, ASTM A852 (A709-70W) is a high-performance weathering steel that delivers 70 ksi minimum yield strength, guaranteed toughness at -40°F, and long-term atmospheric durability. It is the material of choice for engineers designing landmark bridges and exposed structures in demanding environments, where structural efficiency, safety, and minimal maintenance are paramount. Its successful use depends fundamentally on knowledgeable design that respects the material's unique behavior and environmental requirements.** -:- For detailed product information, please contact sales. -: ASTM A852 Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4549 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 A852 Steel Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A852 Steel -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A852 Steel -:- For detailed product information, please contact sales. -:

Packing of ASTM A852 Steel -:- 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 1020 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