AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS)

AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS) Product Information -:- For detailed product information, please contact sales. -: AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS) Synonyms -:- For detailed product information, please contact sales. -:

AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS) Product Information -:- For detailed product information, please contact sales. -: **Product Name:** AK Steel ASTM A1011, Grade 50 Hot-Rolled Carbon Steel, Structural Steel (SS) --- ### **1. Overview** AK Steel's ASTM A1011 Grade 50 is a high-strength structural steel that represents a significant performance tier in the hot-rolled steel spectrum. With a minimum yield strength of 50 ksi (345 MPa), it offers a substantial strength increase over more common grades like 36 or 45, enabling major weight savings and enhanced load capacity in structural designs. This grade is a critical bridge between conventional carbon steels and the higher-end, specialized high-strength low-alloy (HSLA) grades. It is engineered to meet the demanding requirements of heavy construction, transportation, and industrial equipment where strength, durability, and efficient material use are paramount. --- ### **2. International Standards** This product is manufactured to comply with the following key international standard, with specific attention to its high-strength designation: * **ASTM A1011 / A1011M:** Standard Specification for Steel, Sheet and Strip, Hot-Rolled, Carbon, Structural, High-Strength Low-Alloy and High-Strength Low-Alloy with Improved Formability. * This product meets the requirements for **Grade 50**. It is typically supplied under the **High-Strength Low-Alloy (HSLA)** or **Structural Steel (SS)** categories within this standard, indicating a controlled chemistry for enhanced properties. --- ### **3. Chemical Composition (Typical, % by Weight)** Grade 50 achieves its higher strength through a carefully balanced chemistry that may include microalloying elements. The carbon content is controlled to maintain weldability. | Element | Content (Maximum, unless specified) | Role & Implication | | :--- | :--- | :--- | | **Carbon (C)** | 0.20% max (often lower, e.g., 0.10-0.15%) | Provides base strength. Kept relatively low to preserve weldability and toughness, with strength supplemented by other elements. | | **Manganese (Mn)** | 1.00% - 1.50% | A primary strengthening and hardening element. Higher levels than in lower grades. | | **Phosphorus (P)** | 0.035% max | Residual; kept low. | | **Sulfur (S)** | 0.035% max | Residual; kept low. | | **Silicon (Si)** | 0.10% - 0.40% | Deoxidizer and solid solution strengthener. | | **Columbium (Cb/Nb)** | **0.005% - 0.05%** (Common) | **Key Microalloy.** Provides grain refinement and precipitation strengthening, allowing for higher strength without drastically increasing carbon. | | **Vanadium (V)** | **0.01% - 0.08%** (May be used) | **Microalloy.** Enhances strength through precipitation hardening. | | **Aluminum (Al), Total** | 0.010% min | Grain refiner for killed steel practice. | | **Copper (Cu)** | 0.20% min (when specified) | Optional for improved atmospheric corrosion resistance (2x that of carbon steel). | **Key Characteristic:** Grade 50 often utilizes **microalloying (Nb, V)**. This modern approach achieves high strength with a lower carbon equivalent (CE) compared to traditional carbon-manganese steels of similar strength, leading to vastly improved weldability and toughness. --- ### **4. Physical & Mechanical Properties** Properties are achieved via a controlled rolling process that exploits microalloy precipitation and grain refinement. | Property | Specification Minimum (ASTM A1011 for Grade 50) | Typical Value / Description | | :--- | :--- | :--- | | **Yield Strength (min)** | 50 ksi (345 MPa) | | | **Tensile Strength** | 65 ksi min (450 MPa) | Typically ranges from 65 - 85 ksi (450 - 585 MPa). | | **Elongation in 2" (min)** | 18% - 22% (varies with thickness) | Maintains good ductility for its high strength level. | | **Yield-to-Tensile Ratio** | Generally 0.75 - 0.85 | Indicates efficient material utilization. | | **Modulus of Elasticity** | 29,000 ksi (200 GPa) | | | **Notch Toughness** | **Excellent.** The fine-grained microstructure from microalloying provides superior impact resistance, especially at lower temperatures. | Often specified where dynamic loading or low-temperature service is a concern. | | **Surface Finish** | Standard hot-rolled mill finish. | | --- ### **5. Key Features & Advantages** * **High Strength-to-Weight Ratio:** Enables the design of lighter, stronger structures, reducing material costs, shipping weight, and energy consumption. * **Excellent Weldability (for its strength):** The microalloyed, lower-carbon chemistry results in a favorable carbon equivalent, significantly reducing preheat requirements and the risk of hydrogen cracking compared to carbon-strengthened steels of similar yield strength. * **Superior Toughness:** The fine-grained ferrite microstructure provides exceptional resistance to brittle fracture and better performance under impact or cyclic loading. * **Good Formability:** Can be cold formed, bent, and punched, though it requires more force and larger bend radii than lower-strength grades. * **Enhanced Durability:** When supplied with copper, it offers improved resistance to atmospheric corrosion. --- ### **6. Product Applications** ASTM A1011 Grade 50 is a preferred material for heavy-duty, weight-sensitive structural applications across multiple industries. * **Construction & Infrastructure:** Building frames, columns, and long-span beams where load capacity is critical; bridge girders and components. * **Heavy Equipment & Mining:** Excavator booms, crane arms, bulldozer blades, haul truck frames, and mining equipment structural members. * **Transportation:** Trailer main beams, dump truck bodies, railcar underframes, bus chassis, and military vehicle components. * **Material Handling:** Heavy-duty racking systems for warehouses, lifting devices, and conveyor support structures. * **Agricultural Machinery:** High-stress frames for large tractors, combines, and balers. * **Energy:** Wind turbine towers (non-welded sections), transmission poles, and equipment supports in power plants. --- ### **7. Fabrication & Processing Notes** * **Descaling:** Mill scale removal via blasting or pickling is required for quality welding and painting. * **Forming:** Cold forming is possible but demands more power. Minimum recommended bend radius is typically 2.5x to 3x material thickness (t) for a 90-degree bend. * **Welding:** **Highly weldable with proper practice.** Low-hydrogen processes (MIG with 100% CO₂ or 75/25 Ar/CO₂, FCAW, SMAW with E7018) are standard. Preheating of 50-200°F (10-95°C) is often recommended for thicker sections (>0.75") or in restrained conditions, but requirements are less stringent than for carbon-equivalent Grade 50 steels without microalloys. * **Cutting:** All thermal cutting methods (plasma, laser, oxy-fuel) work well. * **Galvanizing:** An excellent candidate for hot-dip galvanizing due to its controlled, typically low-silicon chemistry. --- **Disclaimer:** *This profile is a technical summary. AK Steel is now part of Cleveland-Cliffs Inc.* For engineering and procurement, always refer to the latest **ASTM A1011** specification and the certified **Mill Test Report (MTR)**. The exact microalloying (Nb, V) and resultant mechanical properties can vary by producer and melt. The MTR provides the legally binding data for your specific material, including chemistry, mechanical properties, and applicable tolerances. -:- For detailed product information, please contact sales. -: AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS) Specification Dimensions Size： Diameter 20-1000 mm Length <4587 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. -: AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS) Properties -:- For detailed product information, please contact sales. -:

Applications of AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS) -:- For detailed product information, please contact sales. -: Chemical Identifiers AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS) -:- For detailed product information, please contact sales. -:

Packing of AK Steel ASTM A 1011, Grade 50 Hot Rolled Carbon Steel, Structural Steel (SS) -:- 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 1058 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