AK Steel ASTM A 1011, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA)

AK Steel ASTM A 1011, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA) Product Information -:- For detailed product information, please contact sales. -: AK Steel ASTM A 1011, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA) Synonyms -:- For detailed product information, please contact sales. -:

AK Steel ASTM A 1011, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA) Product Information -:- For detailed product information, please contact sales. -: **Product Name:** AK Steel ASTM A1011, Class 2 Formable, Grade 45K Hot-Rolled Medium/High Strength Low-Alloy Steel (HSLA) --- ### **1. Overview** AK Steel's ASTM A1011 **Grade 45K, Class 2 Formable** is a versatile and widely used microalloyed High-Strength Low-Alloy (HSLA) steel that provides a reliable 45 ksi (310 MPa) minimum yield strength with balanced, standard formability characteristics. The **"K" suffix** confirms microalloying with Columbium (Niobium) and/or Vanadium for enhanced strength and toughness, while the **"Class 2 Formable"** designation represents the baseline, standard formability level within the A1011 specification for HSLA grades. This grade is engineered as a cost-effective workhorse for structural and component applications where higher strength and weight savings are desired, but the forming requirements are moderate and do not necessitate the enhanced ductility of Class 1. --- ### **2. International Standards** This product conforms to the following North American standard for HSLA sheet and strip, meeting its standard formability class: * **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. * **Grade:** 45K (Microalloyed HSLA Steel) * **Formability Class:** **Class 2 (Structural).** This is the default and most common class for HSLA steels, providing a standard level of ductility suitable for typical structural fabrication like bending, roll-forming, and simple stamping. It has slightly higher tensile strength allowances and lower minimum elongation than Class 1. --- ### **3. Chemical Composition (Typical, % by Weight)** The chemistry is a balanced, low-carbon microalloyed design optimized for consistent performance and weldability. | Element | Content (Typical / Maximum) | Role & Implication | | :--- | :--- | :--- | | **Carbon (C)** | 0.12% - 0.18% max | Kept relatively low for good weldability and formability. Strength is supplemented by microalloys. | | **Manganese (Mn)** | 1.00% - 1.35% | Primary solid solution strengthener. | | **Phosphorus (P)** | 0.035% max | Residual; kept low. | | **Sulfur (S)** | 0.035% max | Residual; controlled for standard weldability and formability. | | **Silicon (Si)** | 0.10% - 0.40% | Deoxidizer. | | **Columbium (Cb/Nb)** | **0.005% - 0.04%** | Primary microalloy for grain refinement and precipitation strengthening. | | **Vanadium (V)** | **0.01% - 0.06%** (may be used alone or with Nb) | Provides additional precipitation strengthening. | | **Aluminum (Al), Total** | 0.010% min | Grain refiner for fine austenite grain size. | | **Key Characteristic:** | **Low Carbon Equivalent (CE).** Typically ≤ 0.37, ensuring good weldability and a favorable balance of strength and toughness for structural applications. | | --- ### **4. Physical & Mechanical Properties** Properties reflect the standard "Structural" (Class 2) formability level, prioritizing reliable strength. | Property | Specification Minimum (ASTM A1011, Grade 45K, Class 2) | Typical Value / Description | | :--- | :--- | :--- | | **Yield Strength (min)** | 45 ksi (310 MPa) | | | **Tensile Strength** | 60 ksi min (415 MPa) | Typically 60-75 ksi. **Note:** Class 2 allows for higher tensile strength than Class 1, resulting in a higher yield-to-tensile ratio. | | **Yield-to-Tensile Ratio (Y/T)** | **Higher than Class 1** | Typically 0.80 - 0.88. Indicates a stronger, less ductile material behavior compared to Class 1, but still suitable for many forming operations. | | **Elongation in 2" (min)** | **Standard for structural grades** (e.g., 18-21% min, thickness dependent) | Provides adequate ductility for standard bending and forming. Lower minimum than Class 1. | | **Modulus of Elasticity** | 29,000 ksi (200 GPa) | | | **Notch Toughness** | **Very Good.** The microalloyed, fine-grained microstructure provides good impact resistance, suitable for most structural applications. | | | **Surface Finish** | Standard hot-rolled mill finish. | | --- ### **5. Key Features & Advantages** * **Reliable Strength & Economy:** Offers a significant 45 ksi yield strength at a cost-effective point, providing an excellent strength-to-cost ratio for structural upgrades over mild steel. * **Good Fabricability:** Maintains good weldability and sufficient formability for common structural fabrication processes like bending, punching, and moderate roll-forming. * **Weight Reduction:** Enables down-gauging compared to lower-strength steels like Grade 36, reducing material weight. * **Enhanced Toughness:** Superior notch toughness and impact resistance compared to traditional carbon-manganese steels of similar strength. * **Wide Availability & Predictability:** As a standard HSLA grade, it is readily available and offers predictable, consistent performance. --- ### **6. Product Applications** ASTM A1011 Grade 45K Class 2 is a versatile choice for a broad range of structural and component applications requiring upgraded strength. * **Building & Construction:** Structural members, purlins, girts, light building frames, and metal building components. * **Transportation:** Trailer frames, dump truck subframes, railcar structural members, and bus chassis components. * **Agricultural & Material Handling:** Equipment frames, loader arms, conveyor supports, and medium-duty racking systems. * **General Fabrication:** Brackets, supports, guards, and platforms where higher load capacity is needed. * **Industrial Equipment:** Machine bases, weldments, and support structures for moderate-duty service. --- ### **7. Fabrication & Processing Notes** * **Forming:** Suitable for **cold bending and moderate forming**. Minimum recommended bend radii are typically **2.5x to 3.5x material thickness**. More force is required than for mild steel, and springback is more pronounced. Not recommended for severe deep drawing or stretch forming. * **Welding:** **Good weldability.** Use low-hydrogen processes (GMAW, FCAW). Preheating (100-200°F / 40-95°C) is recommended for material over 0.75" thick or in restrained joints. Use filler metals with matching or slightly lower strength (e.g., 70 ksi tensile). * **Cutting:** All standard cutting methods (plasma, laser, oxy-fuel) are applicable. * **Surface Preparation:** Mill scale must be removed by pickling or abrasive blasting for painting. * **Comparison to Class 1:** Choose Class 2 when forming requirements are straightforward (simple bends, roll-forming). Choose **Class 1** if the part design involves more complex shapes, tighter bend radii, or greater concern for forming consistency. --- **Disclaimer:** *This profile is a technical summary. AK Steel is now part of Cleveland-Cliffs Inc.* For engineering and procurement, always consult the latest official **ASTM A1011** specification and the certified **Mill Test Report (MTR)**. If formability is a key concern, ensure the purchase order specifies the required **Formability Class (Class 1 or Class 2)**. For Grade 45K, the default is often Class 2 if not otherwise specified, but confirmation is essential. -:- For detailed product information, please contact sales. -: AK Steel ASTM A 1011, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA) Specification Dimensions Size： Diameter 20-1000 mm Length <4598 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, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA) Properties -:- For detailed product information, please contact sales. -:

Applications of AK Steel ASTM A 1011, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA) -:- For detailed product information, please contact sales. -: Chemical Identifiers AK Steel ASTM A 1011, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA) -:- For detailed product information, please contact sales. -:

Packing of AK Steel ASTM A 1011, Class 2 Formable, Grade 45K Hot Rolled Carbon Steel, Medium/High Strength Low Alloy Steel (HSLA) -:- 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 1069 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