AISI 50B40H Steel Seamless tube

AISI 50B40H Steel Seamless tube Product Information -:- For detailed product information, please contact sales. -: AISI 50B40H Steel Seamless tube Synonyms -:- For detailed product information, please contact sales. -:

AISI 50B40H Steel Product Information -:- For detailed product information, please contact sales. -: **Product Datasheet: AISI 50B40H Boron-Treated Hardenability Steel** --- ### **1. Product Overview** AISI 50B40H is a **medium-carbon, boron-treated alloy steel produced to specific hardenability bands**, designated by the **"H" suffix**. This steel is engineered to achieve consistent through-hardening characteristics across production batches, making it ideal for **high-strength, critical components** where predictable heat treatment response is essential. The controlled addition of boron provides exceptional hardenability at a lower alloy cost compared to conventional chromium-molybdenum steels, offering excellent value for demanding applications. --- ### **2. Key International & Equivalent Standards** - **Primary Standard:** **SAE J404, J412, J770** (SAE-AISI 50B40H) - **Hardenability Specification:** **ASTM A304** – Standard Specification for Steel Bars, Alloy, Subject to End-Quench Hardenability Requirements - **Bar Stock Standard:** **ASTM A29/A29M** – Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought - **European Equivalents:** No direct equivalent; functionally similar to **34CrB4 (1.7321)** with modified composition for hardenability control. - **Japanese Equivalent:** Approximated by **SCr440H-B** or similar boron-treated variants under JIS G4052. - **ISO Reference:** ISO 683-1:2016 (Thermomechanical processed steels) – Similar to Type 34CrB4 with H-band controls. --- ### **3. Chemical Composition (Weight % - ASTM A304 H-Steel Ranges)** The composition is controlled to ensure the steel meets specified hardenability bands rather than strict chemical limits alone. Typical ladle analysis ranges are: | Element | Minimum (%) | Maximum (%) | Typical Target (%) | Primary Function | | :--- | :--- | :--- | :--- | :--- | | **Carbon (C)** | 0.36 | 0.44 | 0.40 | Primary strength and hardness contributor. | | **Manganese (Mn)** | 0.70 | 1.00 | 0.85 | Enhances hardenability and strength. | | **Phosphorus (P)** | — | 0.035 | 0.020 | Residual element (controlled impurity). | | **Sulfur (S)** | — | 0.040 | 0.025 | Improves machinability (forms MnS inclusions). | | **Silicon (Si)** | 0.15 | 0.35 | 0.25 | Deoxidizer, solid solution strengthening. | | **Boron (B)** | 0.0005 | 0.003 | 0.0015 | **Powerful hardenability enhancer**; maximizes depth of hardening. | | **Residual Alloys (Cr, Ni, Mo)** | Usually ≤ 0.35% combined unless specified. | | | | **Note:** For H-steels, the actual chemical composition may vary within the above ranges to guarantee the hardenability band is met. The **End-Quench Hardenability Test (Jominy Test)** is the primary acceptance criterion. --- ### **4. Hardenability & Mechanical Properties** #### **Hardenability (Per ASTM A255/Jominy Test):** - The **"H" designation** guarantees the distance from the quenched end to achieve a specified hardness (e.g., 40 HRC) falls within a published band. This ensures uniform response to heat treatment in production. - Typical Jominy curve shows high hardenability; 40 HRC may be maintained up to **J20–J30 (20–30 mm from quenched end)** or further, depending on the specific heat and grain size. #### **Mechanical Properties (After Quench & Temper – Typical):** *Properties vary with section size and tempering temperature.* - **Typical Heat Treatment:** - **Austenitizing:** 830°C – 860°C (1525°F – 1580°F) - **Quenching:** **Oil quench** (effective for sections up to ~100 mm/4 in diameter due to boron effect) - **Tempering:** 425°C – 650°C (800°F – 1200°F) for optimized toughness/strength balance. - **Example Properties (Tempered at 540°C / 1000°F):** - **Tensile Strength:** 850 – 1050 MPa - **Yield Strength (0.2% Offset):** 700 – 900 MPa - **Elongation (in 50 mm):** ≥ 16% - **Reduction of Area:** ≥ 50% - **Hardness:** 28 – 34 HRC - **High-Strength Condition (Low-Temperature Temper ~200°C / 400°F):** - **Hardness:** 48 – 53 HRC - **Tensile Strength:** 1550 – 1750 MPa - **Physical Constants:** - **Density:** ~7.85 g/cm³ - **Modulus of Elasticity:** ~205 GPa - **Thermal Conductivity:** ~45 W/m·K (at 100°C) --- ### **5. Heat Treatment & Processing Characteristics** - **Forging:** Heat to 1150°C – 1200°C (2100°F – 2200°F); finish above 850°C (1550°F); slow cool after forging. - **Annealing:** Full anneal at 830°C – 860°C, furnace cool. Spheroidize annealing is recommended for best machinability. - **Boron Effectiveness:** Boron significantly boosts hardenability but requires **protection from nitrogen** (often via small Al/Ti additions) to form effective BN. - **Weldability:** **Poor** due to high hardenability. Requires preheat (200–315°C / 400–600°F) and post-weld tempering to avoid hydrogen-induced cracking. - **Machinability:** Fair in annealed condition (~187–229 HB). Boron can increase tool wear; proper tool geometry and coolant are recommended. --- ### **6. Primary Applications** AISI 50B40H is selected for **high-stress, safety-critical components** requiring predictable and uniform hardening in mass production: - **Automotive & Truck:** **Axle shafts**, steering knuckles, torsion bars, crankshafts, high-strength connecting rods, and suspension components. - **Agricultural & Construction:** Gears, heavy-duty shafts, track pins, hydraulic cylinder rods, and pivot pins. - **Industrial Machinery:** Large bolts, studs, spindles, and drivetrain components subject to high torsional/bending loads. - **Oil & Gas:** Non-critical fasteners and machinery parts requiring good strength-to-cost ratio. --- ### **7. Key Advantages & Selection Rationale** - **Predictable Performance:** The **H-band guarantee** ensures consistent depth of hardening and mechanical properties across lots, reducing heat treatment variability in production. - **Cost-Effective Hardenability:** Boron provides hardenability comparable to higher-alloy steels (e.g., 4140H, 4340H) at a significantly lower material cost. - **Design Flexibility:** Suitable for larger cross-sections where through-hardening is required with minimal distortion (oil quench sufficient). - **Quality Assurance:** Supplied with certified hardenability data, providing engineers with reliable data for design and process validation. --- ### **Disclaimer** This datasheet provides general information per industry standards. For critical applications, material must be sourced to **ASTM A304 H-band requirements** with certified mill test reports. Final mechanical properties are dependent on the component's geometry, heat treatment process parameters (quench severity, tempering cycle), and machining operations. Weld procedures must be rigorously qualified. -:- For detailed product information, please contact sales. -: AISI 50B40H Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4094 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. -: AISI 50B40H Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 50B40H Steel Seamless tube -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 50B40H Steel Seamless tube -:- For detailed product information, please contact sales. -:

Packing of AISI 50B40H Steel Seamless tube -:- 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 Seamless tube 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 565 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