Bethlehem Steel ASTM A572 Grade 50, as-rolled steel

Bethlehem Steel ASTM A572 Grade 50 3/16 to 1-1/2 in. thick, as-rolled steel plate Product Information -:- For detailed product information, please contact sales. -: Bethlehem Steel ASTM A572 Grade 50 3/16 to 1-1/2 in. thick, as-rolled steel plate Synonyms -:- For detailed product information, please contact sales. -:

Bethlehem Steel ASTM A572 Grade 50 3/16 to 1-1/2 in. thick, as-rolled steel plate Product Information -:- For detailed product information, please contact sales. -: # **Bethlehem Steel ASTM A572 Grade 50 (3/16" to 1-1/2" thick) As-Rolled High-Strength Low-Alloy (HSLA) Steel Plate** --- ## **1. Overview** Bethlehem Steel's **ASTM A572 Grade 50** plate is the **industry-standard, high-strength low-alloy (HSLA) structural steel**, renowned for its optimal balance of strength, weldability, toughness, and economy. Available in the **as-rolled condition** from **3/16" to 1-1/2"** thick, this microalloyed steel delivers a **50 ksi (345 MPa) minimum yield strength**, providing a **39% strength increase** over A36 and enabling significant weight reduction in designs. The "HSLA" designation signifies that its enhanced properties are achieved through micro-additions of elements like Columbium (Niobium) and Vanadium, which refine the grain structure and provide precipitation strengthening. This results in a material that is not only stronger but also offers superior notch toughness and more favorable welding characteristics than traditional carbon-strengthened steels of equivalent strength, making it the predominant choice for modern structural fabrication. --- ## **2. International Standards** This product conforms to the premier North American specification for HSLA structural steels: * **Primary Standard: ASTM A572 / A572M** – Standard Specification for High-Strength Low-Alloy Columbium-Vanadium Structural Steel. * **Grade Designation:** **50** (indicating 50 ksi minimum yield strength). This is the most widely specified and available grade within the A572 family. * **Key Metallurgical Distinction:** An **HSLA (microalloyed) steel**, distinct from carbon-strengthened grades like A529. Its low carbon content coupled with microalloying provides a superior combination of properties. * **Ubiquitous Cross-References & Applications:** * **ASTM A992:** The standard for rolled structural wide-flange shapes, which typically specifies a 50 ksi minimum yield and is metallurgically similar to A572 Gr. 50. * **ASTM A709 Grade 50:** The bridge steel specification, incorporating A572 Grade 50 requirements with additional toughness mandates. * **AASHTO M270 Grade 50:** The standard for bridges using non-weathering steel. --- ## **3. Chemical Composition (Typical, % by Weight)** The chemistry is a precisely controlled, low-carbon, microalloyed system designed for performance and manufacturability. | Element | Content (Maximum, per ASTM A572 Gr. 50) | Role & Implication | | :--- | :--- | :--- | | **Carbon (C)** | **0.23% max** | Kept low to ensure excellent weldability and toughness. Primary strength is derived from microalloys, not high carbon. | | **Manganese (Mn)** | **1.35% max** | Provides solid solution strengthening and works synergistically with microalloys. | | **Phosphorus (P)** | 0.04% max | Residual; kept low. | | **Sulfur (S)** | 0.05% max | Residual; controlled. Modern production often achieves much lower levels (<0.010%). | | **Silicon (Si)** | 0.40% max | Deoxidizer. | | **Columbium (Cb/Nb)** | **0.005% - 0.05%** | **Primary Microalloy.** Key for grain refinement during rolling and precipitation strengthening, enabling high strength with low carbon. | | **Vanadium (V)** | **0.01% - 0.15%** | **Microalloy.** Provides potent precipitation strengthening; often used in combination with Nb. | | **Nitrogen (N)** | 0.015% max | Controlled as it interacts with microalloys. | | **Key Characteristic:** | **Low Carbon Equivalent (CE).** Typical CE is **0.38-0.44**. This is **significantly lower than a carbon-strengthened 50 ksi steel (e.g., A529 Gr. 50)**. This low CE is the foundation of its **excellent weldability** and **good heat-affected zone (HAZ) toughness**. | | --- ## **4. Physical & Mechanical Properties (As-Rolled)** The fine-grained, microalloyed ferrite-pearlite microstructure provides an excellent property profile. | Property | ASTM A572 Grade 50 Specification Minimum | Typical Value / Characteristics | | :--- | :--- | :--- | | **Yield Strength (min)** | **50 ksi (345 MPa)** | Typically 50-60 ksi. Very consistent. | | **Tensile Strength** | **65 ksi min (450 MPa)** | Typically 65-80 ksi. | | **Elongation in 2" (min)** | **18%** (for thickness ≤ 1.5") | Typically 20-25%. Maintains good ductility for forming. | | **Yield-to-Tensile Ratio** | N/A | Typically 0.77 - 0.85. Efficient use of material strength. | | **Modulus of Elasticity** | 29,000 ksi (200 GPa) | | | **Notch Toughness** | **Not in base spec, but inherently very good.** | The fine-grained structure provides **excellent impact resistance**, far superior to as-rolled carbon steels. Routinely meets supplemental Charpy requirements (e.g., 20 ft-lb @ +40°F or 0°F). | | **Fatigue Strength** | High | Good performance under cyclic loading. | | **Surface Finish** | Standard hot-rolled mill finish. | | --- ## **5. Key Features & Advantages** * **Optimal Strength-to-Weight Ratio:** The 50 ksi yield strength is the "sweet spot" for structural design, offering substantial weight savings over A36 without the fabrication complexities of ultra-high-strength steels. * **Superior Weldability:** The low carbon equivalent allows welding with minimal or no preheat in most thicknesses, drastically reducing fabrication cost and complexity compared to A529 Gr. 50. * **Excellent Toughness:** Provides reliable resistance to brittle fracture, making it suitable for dynamically loaded structures and lower temperature service. * **Good Formability & Machinability:** Can be readily bent, punched, and machined using standard shop practices. * **Cost-Effective Performance:** The benchmark for value in high-strength structural steel, offering the best overall performance for its cost. --- ## **6. Product Applications** ASTM A572 Grade 50 is the **workhorse high-strength steel** across virtually all structural sectors: * **Building Construction:** Columns, beams, trusses, and built-up sections in commercial, industrial, and institutional buildings. * **Bridge Construction:** Girders, diaphragms, cross-frames, and connection plates (often specified as A709 Gr. 50). * **Heavy Equipment & Machinery:** Frames, booms, and structural components for construction, mining, and agricultural equipment. * **Transportation:** Trailer frames, truck chassis, railcar components, and shipping containers. * **Transmission & Communication Towers:** Primary structural members. * **Storage & Racking:** Beams and uprights for heavy-duty industrial storage systems. --- ## **7. Fabrication & Processing Notes** * **Cutting:** Excellent for all methods: shearing, plasma, laser, and flame cutting. No special precautions required for thicknesses within this range. * **Forming:** Good cold formability. Minimum recommended bend radius is typically **2.5t to 3t** for a 90° bend. More springback than mild steel. * **Welding:** **Highly weldable, a major advantage.** * **Preheat:** Generally **not required** for thicknesses **under 1 inch** in normal conditions. For thicknesses >1" or in cold/restrained joints, a preheat of **100-200°F (40-95°C)** is good practice. * **Electrodes/Process:** All common processes are suitable. Use low-hydrogen electrodes (E7018) for SMAW or deoxidized wires (ER70S-6) for GMAW for optimal results. Matching strength (70 ksi) filler metals are standard. * **Comparison to A529 Gr. 50:** **Far more forgiving.** Lower risk of HAZ cracking, simpler procedures, reduced need for preheat. * **Machining:** Good machinability with proper tooling. --- ## **8. Modern Perspective & Comparison** * **vs. ASTM A36:** **Stronger (50 vs 36 ksi yield).** The default upgrade for weight reduction and increased load capacity. The slight cost premium is almost always justified. * **vs. ASTM A529 Grade 50:** The direct competitor. **A572 (HSLA) is the unequivocally superior material** due to its lower CE (better weldability) and inherent toughness. **A529 is largely obsolete for new designs** where weldability matters. * **vs. ASTM A992:** For plates, A572 Gr. 50 is used. A992 is the specification for rolled structural shapes (I-beams), which are typically made from steel meeting A572 Gr. 50 chemistry. * **Current Status:** **ASTM A572 Grade 50 is the dominant, most important high-strength structural steel plate in North America.** It is universally produced, stocked, and specified. It represents the standard against which other structural steels are measured. --- **Disclaimer:** *This profile describes the industry-standard high-strength structural steel. Bethlehem Steel is now part of Cleveland-Cliffs Inc.* **For procurement and fabrication:** 1. **This is the recommended grade** for most applications requiring 50 ksi yield strength. 2. Consult the latest **ASTM A572** specification. 3. Welding can follow standard **AWS D1.1** practices for 50 ksi steel. 4. For bridge work, ensure you specify **ASTM A709 Grade 50** if required by the governing authority. 5. Always review the MTR to confirm properties. The consistent quality of A572 Gr. 50 is one of its greatest assets. -:- For detailed product information, please contact sales. -: Bethlehem Steel ASTM A572 Grade 50 3/16 to 1-1/2 in. thick, as-rolled steel plate Specification Dimensions Size： Diameter 20-1000 mm Length <4626 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 ASTM A572 Grade 50 3/16 to 1-1/2 in. thick, as-rolled steel plate Properties -:- For detailed product information, please contact sales. -:

Applications of Bethlehem Steel ASTM A572 Grade 50 3/16 to 1-1/2 in. thick, as-rolled steel plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Bethlehem Steel ASTM A572 Grade 50 3/16 to 1-1/2 in. thick, as-rolled steel plate -:- For detailed product information, please contact sales. -:

Packing of Bethlehem Steel ASTM A572 Grade 50 3/16 to 1-1/2 in. thick, as-rolled steel 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 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 1097 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