Bethlehem Steel ASTM A656 Grade 50 Type 7, steel

Bethlehem Steel ASTM A656 Grade 50 Type 7, 3/16 to 2 in. thick, steel plate Product Information -:- For detailed product information, please contact sales. -: Bethlehem Steel ASTM A656 Grade 50 Type 7, 3/16 to 2 in. thick, steel plate Synonyms -:- For detailed product information, please contact sales. -:

Bethlehem Steel ASTM A656 Grade 50 Type 7, 3/16 to 2 in. thick, steel plate Product Information -:- For detailed product information, please contact sales. -: ## **Product Specification: Bethlehem Steel ASTM A656 Grade 50 Type 7 Thermomechanically Controlled Processed (TMCP) Steel Plate (3/16" to 2" thick)** ### **Product Overview** Bethlehem Steel ASTM A656 Grade 50 Type 7 is a high-strength, low-alloy (HSLA) structural steel plate produced using the **Thermomechanically Controlled Process (TMCP)**. This advanced manufacturing technique combines precisely controlled rolling with accelerated cooling to achieve a fine-grained microstructure and enhanced mechanical properties without the need for traditional heat treatment like normalizing. Grade 50 Type 7 is specifically engineered to provide an optimal balance of high strength (50 ksi minimum yield), good toughness, and **exceptional weldability**, making it a cost-effective and efficient material choice for weight-sensitive applications where fabrication ease is paramount. ### **International Standard Compliance** * **Primary Standard:** **ASTM A656 / A656M** - Standard Specification for High-Strength Low-Alloy Structural Steel Plate Produced by Thermomechanical Controlled Processing. * **Grade & Type Designation:** **Grade 50, Type 7**. The "Type" denotes a specific chemical composition and property set. Type 7 is renowned for its superior weldability characteristics. * **International Equivalents (Conceptual):** * **EN Standard:** EN 10149-2 **S355MC** or **S420MC** (Hot-rolled, thermomechanically rolled weldable fine grain steels). While strength grades differ, the TMCP production philosophy and application are similar. * **JIS Standard:** G3136 **SPFH** series (Hot-rolled high strength steel plates for welded structure). * **ISO Standard:** ISO 4950-3 or ISO 5951 (High yield strength weldable steels). * **Key Differentiator:** Unlike quenched & tempered (Q&T) or normalized plates, A656 Type 7 derives its properties from the TMCP rolling process itself, offering potential cost and energy savings. --- ### **Chemical Composition (Heat Analysis, Weight %)** The chemistry of Type 7 is meticulously designed for the TMCP process, featuring low carbon and carbon equivalent (CE) for weldability, micro-alloyed with elements like Niobium (Nb) or Vanadium (V) for grain refinement and precipitation strengthening. | Element | ASTM A656 Gr.50 Type 7 Typical Range | Purpose & Notes | | :--- | :--- | :--- | | **Carbon (C)** | 0.10% max | **Very low.** The cornerstone of Type 7's excellent weldability and toughness. | | **Manganese (Mn)** | 1.50% max | Primary solid solution strengthener. Provides strength without excessively raising the CE. | | **Phosphorus (P)** | 0.025% max | Tightly controlled impurity for improved toughness. | | **Sulfur (S)** | 0.010% max | **Ultra-low sulfur.** Enhances through-thickness (Z-direction) properties and weld metal soundness. | | **Silicon (Si)** | 0.30% max | Deoxidizer, contributes to strength. | | **Copper (Cu)** | 0.20% min (when specified) | Optional for atmospheric corrosion resistance. | | **Vanadium (V)** | 0.10% max | Primary micro-alloying element for precipitation strengthening. | | **Niobium (Cb/Nb)** | 0.05% max | Powerful grain refiner; inhibits recrystallization during rolling for ultra-fine grains. | | **Titanium (Ti)** | 0.10% max | Sometimes added for grain size control and nitride formation. | | **Aluminum (Al)** | 0.010 - 0.060% | Grain refiner (Aluminum-killed steel). | | **Nitrogen (N)** | 0.015% max | Controlled to optimize micro-alloy precipitation. | | **Carbon Equivalent (CE IIW)** | **Typically ≤ 0.36** | CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15. **Extremely low, a hallmark of Type 7.** | | **Pcm (Weld Crack Parameter)** | **Typically ≤ 0.18** | Pcm = C + Si/30 + Mn/20 + Cu/20 + Ni/60 + Cr/20 + Mo/15 + V/10 + 5B. Further demonstrates superior weldability. | **TMCP Process Note:** The plate is finish-rolled in the non-recrystallization region of austenite and then subjected to Accelerated Cooling (ACC). This results in a fine ferrite-bainite microstructure, providing high strength and toughness directly from the mill. --- ### **Physical & Mechanical Properties** #### **1. Standard Mechanical Properties (As TMCP processed):** * **Yield Strength (min):** 50 ksi (345 MPa) * **Tensile Strength:** 65 - 80 ksi (450 - 550 MPa) * **Yield-to-Tensile Ratio:** 0.75 - 0.85 (typical) * **Elongation in 2" (min):** 22% (for thickness ≤ 3/4") * **Elongation in 8" (min):** 20% (for thickness ≤ 3/4") * **Reduction of Area (typical):** 50 - 65% #### **2. Impact Properties (When Specified):** * **Charpy V-Notch Testing:** Available as specified by purchaser. * **Typical Test Condition:** 15 - 20 ft-lb (20 - 27 J) at 0°F (-18°C) or -20°F (-29°C). * **Typical Performance:** Often achieves 40 - 70 ft-lb (54 - 95 J) at 0°F, demonstrating good toughness from the TMCP structure. #### **3. Physical Constants:** * **Density:** 0.284 lb/in³ (7.85 g/cm³) * **Modulus of Elasticity:** 29,000 ksi (200 GPa) * **Coefficient of Thermal Expansion:** 6.5 × 10⁻⁶/°F (11.7 × 10⁻⁶/°C) * **Thermal Conductivity:** ~28 BTU·in/(hr·ft²·°F) #### **4. Technological Properties:** * **Weldability:** **Excellent.** The very low carbon and CE make it **one of the most weldable high-strength structural steels**. Minimal to no preheat is required for most thicknesses. * **Preheat/Interpass Guidelines:** * ≤ 1" thick: Generally not required. * 1" to 2" thick: May benefit from a mild preheat of 50-150°F (10-66°C) under highly restrained conditions. * **Recommended Welding Processes:** All common processes (SMAW, GMAW, FCAW, SAW). Matching or slightly under-matching filler metals can be used effectively. * **Machinability:** Good (approx. 65% of B1112 steel). * **Formability:** Good; minimum bend radius of approx. 2t for 90° bending. --- ### **Product Applications** #### **1. Heavy Equipment & Machinery:** * Excavator booms, arms, and undercarriages * Crane boom sections and jibs * Mining and earthmoving equipment frames * Agricultural machinery structural components #### **2. Transportation & Automotive:** * Heavy-duty truck chassis and frame rails * Trailer frames and gooseneck sections * Rail car components (center sills, bolsters) * Specialized transport and hauling equipment #### **3. Structural & Construction:** * High-performance beams and columns in buildings * Bridge components where weight reduction is critical * Industrial plant structural supports * Material handling system frameworks #### **4. Energy & Industrial:** * Support structures for renewable energy installations (wind, solar) * Pressure vessel skirts and non-pressure supports * Heavy industrial base plates and frames ### **Advantages of TMCP (A656 Type 7) over Conventional Grades** 1. **Enhanced Weldability:** Lower preheat costs, reduced risk of welding defects. 2. **Good Strength-Toughness Balance:** Fine TMCP microstructure provides both. 3. **Potential Cost Savings:** Eliminates need for post-rolling heat treatment (normalizing). 4. **Weight Reduction:** 50 ksi yield allows lighter designs vs. A36 steel. 5. **Consistent Quality:** Controlled process ensures uniform properties. ### **Procurement & Quality Notes** * Condition is **As TMCP Processed** (may be noted as "TMC" or similar). * Specify: **ASTM A656 Grade 50 Type 7**, dimensions, and any required impact testing. * Review Mill Test Reports (MTRs) for confirmed CE and Pcm values to plan fabrication. ### **Disclaimer** This specification is based on the ASTM standard and typical industry data. Properties are achieved through the specific TMCP cycle and may vary slightly. The superior weldability reduces but does not eliminate the need for sound welding practices and procedure qualification where required by code. Always consult the certified MTR and applicable fabrication codes (e.g., AWS D1.1) for the specific material lot. -:- For detailed product information, please contact sales. -: Bethlehem Steel ASTM A656 Grade 50 Type 7, 3/16 to 2 in. thick, steel plate Specification Dimensions Size： Diameter 20-1000 mm Length <4654 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 A656 Grade 50 Type 7, 3/16 to 2 in. thick, steel plate Properties -:- For detailed product information, please contact sales. -:

Applications of Bethlehem Steel ASTM A656 Grade 50 Type 7, 3/16 to 2 in. thick, steel plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Bethlehem Steel ASTM A656 Grade 50 Type 7, 3/16 to 2 in. thick, steel plate -:- For detailed product information, please contact sales. -:

Packing of Bethlehem Steel ASTM A656 Grade 50 Type 7, 3/16 to 2 in. thick, 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 1125 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