Bethlehem Steel BETHSTAR Grade 70, killed steel

Bethlehem Steel BETHSTAR Grade 70 1/4 to 1 in. thick, killed steel plate Product Information -:- For detailed product information, please contact sales. -: Bethlehem Steel BETHSTAR Grade 70 1/4 to 1 in. thick, killed steel plate Synonyms -:- For detailed product information, please contact sales. -:

Bethlehem Steel BETHSTAR Grade 70 1/4 to 1 in. thick, killed steel plate Product Information -:- For detailed product information, please contact sales. -: ## **Product Datasheet: Bethlehem Steel BETHSTAR® Grade 70 Killed Steel Plate** **Product Overview** Bethlehem Steel BETHSTAR® Grade 70 is a premium high-strength, low-alloy (HSLA), **fully killed** steel plate engineered for the most demanding structural and mobile equipment applications. As a killed steel, it undergoes complete deoxidation with silicon and aluminum, resulting in a homogeneous, fine-grained microstructure that ensures superior internal soundness, excellent through-thickness properties, and enhanced toughness. This grade represents the high-strength tier of the BETHSTAR® family, delivering a 70 ksi minimum yield strength while maintaining exceptional weldability and formability. It is commercially available in thicknesses ranging from **1/4 inch (6.4 mm) to 1 inch (25.4 mm)**. **Key International Standards & Specifications** BETHSTAR® Grade 70 was Bethlehem Steel's proprietary specification, designed to bridge the gap between standard structural steels and advanced thermomechanically rolled plates, often meeting or exceeding several prominent standards. * **Primary Equivalent:** **ASTM A572 / A572M Grade 65** (Note: BETHSTAR 70 offers a higher 70 ksi yield vs. A572's 65 ksi maximum standard grade). * **Performance Alternative:** **ASTM A656 Grade 70** (High-Strength Low-Alloy Plate with Improved Formability) – BETHSTAR 70 shares similar strength and formability objectives. * **Also Conforms To:** Key requirements of **ASTM A6** for structural steel plates, typically specified with Supplementary Requirements for impact testing (S1) and/or maximum carbon equivalent (S5). * **Industry Acceptance:** Recognized by major fabricators and OEMs in heavy equipment, transportation, and construction sectors where a proven, weldable 70 ksi killed steel was required. **Chemical Composition (Typical, Weight %)** The chemistry is precisely balanced with microalloying elements (Nb, V) to achieve high strength via precipitation strengthening and grain refinement, while the killed steel practice ensures consistency and toughness. | Element | Typical BETHSTAR® Grade 70 Aim / Range | Key Purpose | | :--- | :--- | :--- | | **Carbon (C)** | 0.15 - 0.20% | Base strength; controlled for weldability | | **Manganese (Mn)** | 1.15 - 1.50% | Solid solution strengthening, hardenability | | **Phosphorus (P)** | ≤ 0.025% | Impurity control | | **Sulfur (S)** | ≤ 0.010% | Impurity control (low for improved toughness) | | **Silicon (Si)** | 0.15 - 0.35% | Deoxidizer (killed steel), solid solution strengthening | | **Columbium (Cb/Nb)** | 0.02 - 0.05% | Grain refinement, precipitation strengthening | | **Vanadium (V)** | 0.04 - 0.08% | Precipitation strengthening | | **Aluminum (Al), Total** | ≥ 0.020% | Essential for fine grain practice (killed steel) | | **Nitrogen (N)** | Controlled | Optimize V/N precipitation | | **Carbon Equivalent (C.E. IIW)** | Typically 0.42 - 0.48 | Indicator of weldability & hardenability | **Physical & Mechanical Properties** | Property | Standard Requirement / Minimum | Typical BETHSTAR® Grade 70 Performance | | :--- | :--- | :--- | | **Yield Strength (Min)** | 70 ksi (483 MPa) | 75 - 85 ksi (517 - 586 MPa) | | **Tensile Strength** | 85 ksi (586 MPa) Min | 90 - 100 ksi (621 - 690 MPa) | | **Elongation in 2" (Min)** | 15% | 16 - 20% | | **Yield-to-Tensile Ratio** | -- | Typically 0.80 - 0.85 (favorable for forming) | | **Modulus of Elasticity** | ~29,000 ksi (200 GPa) | ~29,000 ksi (200 GPa) | | **Density** | 0.284 lb/in³ (7.85 g/cm³) | 0.284 lb/in³ (7.85 g/cm³) | | **Notch Toughness (Typical)** | Can be specified per customer requirements | Excellent Charpy V-Notch impact properties at ambient and sub-zero temperatures due to fine-grained, killed microstructure. | | **Key Feature** | **High-Strength with Fabricability:** Combines 70 ksi yield strength with the internal quality and consistent properties of killed steel, offering a reliable, weldable solution for critical, high-stress components. | | **Product Applications** BETHSTAR® Grade 70 was specified for high-performance applications where maximum strength-to-weight ratio, fatigue resistance, and structural integrity were paramount. * **Heavy-Duty Mobile Equipment:** Main frames, booms, arms, and pivotal components for excavators, cranes, mining shovels, and forestry equipment. * **Transportation & Trucking:** High-stress frame rails, suspension components, and fifth wheels for severe-service trucks, logging trailers, and heavy haulers. * **Lifting & Material Handling:** Structural masts for high-capacity forklifts, crane runways, and heavy-duty lifting device frames. * **Energy & Construction:** Chassis for mobile drilling rigs, support structures, and components subject to high dynamic or impact loads. * **Infrastructure:** Critical connections and highly loaded members in specialized bridges and industrial structures where weight savings are crucial. **Advantages & Fabrication Notes** * **Excellent Weldability:** Despite its high strength, the controlled chemistry and moderate carbon equivalent allow for welding with standard low-hydrogen processes (SMAW, GMAW, FCAW). Proper preheat and procedure qualification are recommended. * **Superior Toughness & Consistency:** The killed, fine-grained microstructure provides reliable notch toughness and uniform mechanical properties through the plate thickness, reducing risk of lamellar tearing. * **Good Formability:** The favorable yield-to-tensile ratio and killed steel ductility allow for successful cold forming and bending operations within recommended radii. * **Proven Performance:** As a branded product from a leading mill, it offered fabricators a reliable, traceable material with consistent performance. * **Legacy Product Note:** BETHSTAR® was a proprietary brand of Bethlehem Steel. Modern equivalents include **ASTM A572 Grade 65 (killed)** and proprietary 70 ksi grades from contemporary producers, often produced via more advanced TMCP processes. **Disclaimer:** This datasheet describes the historical **Bethlehem Steel BETHSTAR® Grade 70** product. For current procurement, engineers should specify performance requirements (70 ksi min yield, killed steel, fine grain, impact values) and work with modern steel producers to select an equivalent grade, such as an ASTM A572 Grade 65 (with higher yield) or a mill-specific 70 ksi HSLA grade, supported by current Mill Test Certification. -:- For detailed product information, please contact sales. -: Bethlehem Steel BETHSTAR Grade 70 1/4 to 1 in. thick, killed steel plate Specification Dimensions Size： Diameter 20-1000 mm Length <4660 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 BETHSTAR Grade 70 1/4 to 1 in. thick, killed steel plate Properties -:- For detailed product information, please contact sales. -:

Applications of Bethlehem Steel BETHSTAR Grade 70 1/4 to 1 in. thick, killed steel plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Bethlehem Steel BETHSTAR Grade 70 1/4 to 1 in. thick, killed steel plate -:- For detailed product information, please contact sales. -:

Packing of Bethlehem Steel BETHSTAR Grade 70 1/4 to 1 in. thick, killed 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 1131 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