AISI 50B44 Steel Seamless tube

AISI 50B44 Steel Seamless tube Product Information -:- For detailed product information, please contact sales. -: AISI 50B44 Steel Seamless tube Synonyms -:- For detailed product information, please contact sales. -:

AISI 50B44 Steel Product Information -:- For detailed product information, please contact sales. -: **Product Datasheet: AISI 50B44 Medium-Carbon Boron Steel** --- ## **1. Product Overview** AISI 50B44 is a **medium-carbon boron-treated alloy steel** engineered to provide an optimal balance of strength, toughness, and hardenability. The controlled addition of boron (typically 0.0005–0.003%) significantly enhances the steel's ability to harden deeply, allowing it to achieve mechanical properties comparable to more heavily alloyed steels, but at a **lower material cost**. It is commonly supplied in the hot-rolled, annealed, or normalized condition and is intended for heat treatment (quenching and tempering) to achieve its final properties. --- ## **2. Key International & Equivalent Standards** | Region/Standard | Equivalent Designation | Key Standard Reference | |----------------|------------------------|------------------------| | **USA** | **SAE/AISI 50B44** | SAE J404, J412, J770 | | | **ASTM A29/A29M** | Standard Grades (Bar Stock) | | **Europe** | Similar to **1.7014 (22MnB4)** adjusted for carbon content | DIN/EN Standard (approx.) | | **Japan** | No direct equivalent; functionally similar to some **SCr or SCM boron steels** | JIS G4053 (approx.) | | **ISO** | Similar to **Type 44B2** in ISO 683-1 (Heat-treatable steels) | ISO 683-1 | *Note: Boron steels often have national/regional specific designations without perfect global 1:1 equivalents.* --- ## **3. Chemical Composition (Weight %, Typical Ladle Analysis)** | Element | Minimum | Maximum | Typical | Role & Effect | |---------|---------|---------|---------|---------------| | **Carbon (C)** | 0.42 | 0.49 | 0.44 | Primary strength & hardness; forms martensite on quenching. | | **Manganese (Mn)** | 0.75 | 1.00 | 0.85 | Increases hardenability, solid solution strengthening. | | **Phosphorus (P)** | — | ≤ 0.035 | 0.020 | Residual (controlled impurity). | | **Sulfur (S)** | — | ≤ 0.040 | 0.025 | Improves machinability. | | **Silicon (Si)** | 0.15 | 0.35 | 0.25 | Deoxidizer, strength enhancement. | | **Boron (B)** | 0.0005 | 0.003 | 0.0015 | **Powerful hardenability enhancer**; segregates to grain boundaries to delay ferrite formation. | | **Chromium (Cr)** | — | ≤ 0.35 (residual) | 0.20 | Residual, minor hardenability contribution. | | **Nickel (Ni)** | — | ≤ 0.35 (residual) | 0.15 | Residual. | *The “B” in 50B44 specifically indicates intentional boron addition for hardenability.* --- ## **4. Physical & Mechanical Properties** ### **As-Supplied Condition (Annealed/Normalized)** - **Hardness:** 187–229 HB - **Tensile Strength:** ~ 620–750 MPa - **Yield Strength:** ~ 415 MPa min - **Elongation:** ~ 20% (in 50 mm) - **Machinability:** Fair to good (~60–65% of 1212 steel standard). ### **After Quench & Temper (Oil Quenched from ~850°C, Tempered at 540°C/1000°F)** - **Hardness:** 28–34 HRC - **Tensile Strength:** 900–1100 MPa - **Yield Strength (0.2% Offset):** 750–950 MPa - **Elongation:** ≥ 16% - **Reduction of Area:** ≥ 50% ### **High-Strength Condition (Low-Temperature Tempered, e.g., 200°C/400°F)** - **Hardness:** 50–55 HRC - **Tensile Strength:** 1650–1850 MPa - **Impact Toughness:** Moderate; adequate for many high-strength applications. ### **Physical Constants** - **Density:** 7.85 g/cm³ - **Modulus of Elasticity:** 205 GPa - **Thermal Conductivity:** ~ 46 W/m·K (at 100°C) --- ## **5. Heat Treatment Guidelines** | Process | Temperature Range | Notes | |---------|------------------|-------| | **Annealing** | 830–860°C (1525–1580°F), slow cool | For machinability & cold work preparation. | | **Normalizing** | 870–900°C (1600–1650°F), air cool | Refines grain structure after forging. | | **Austenitizing (Hardening)** | 830–860°C (1525–1580°F) | Preheat sections >50 mm to avoid cracking. | | **Quenching** | Oil quench recommended | Boron allows through-hardening of sections up to ~75 mm in oil. | | **Tempering** | 200–650°C (400–1200°F) | Adjust for desired strength/toughness balance. Immediate tempering required after quenching. | --- ## **6. Primary Applications** AISI 50B44 is widely used in **medium-to-heavy duty components** requiring high strength, good fatigue resistance, and wear resistance, especially where cost efficiency is critical: - **Automotive & Truck:** Axle shafts, torsion bars, steering components, gear blanks, high-strength bolts. - **Agricultural Machinery:** Gears, shafts, plow beams, pivot pins, harrow teeth. - **General Engineering:** Hydraulic piston rods, spindles, couplings, rollers, and machinery parts subject to high static/dynamic loads. - **Fasteners:** Grade 10.9 and higher bolts, studs, and special fasteners after proper heat treatment. --- ## **7. Key Advantages** - **Cost-Performance Leader:** Achieves high hardenability and strength with minimal alloy content (boron effect). - **Good Through-Hardening:** Suitable for larger sections where uniform properties are required. - **Versatile Heat Treatment Response:** Can be tailored for high hardness/wear or toughened for impact-loaded parts. - **Machinable in Annealed State:** Facilitates near-net shape manufacturing before final heat treatment. --- ## **8. Important Notes & Limitations** - **Weldability:** Generally poor; preheating (200–315°C) and post-weld tempering are essential to avoid hydrogen cracking. - **Boron Sensitivity:** Effective boron requires protection from nitrogen (often via Al/Ti additions); consistent hardenability depends on steelmaking controls. - **Notch Sensitivity:** High-strength conditions may increase sensitivity to sharp notches; proper fillet design and surface finish are important. - **Distortion Control:** As with all through-hardening steels, careful quenching practices (e.g., oil quenching, martempering) help minimize distortion. --- **Disclaimer:** The information provided is typical and based on industry standards. For specific applications, material should be ordered to applicable ASTM/SAE specifications with agreed-upon chemical or hardenability limits. Final properties are dependent on exact heat treatment parameters, part geometry, and manufacturing history. Engineering validation under actual service conditions is recommended. -:- For detailed product information, please contact sales. -: AISI 50B44 Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4095 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 50B44 Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 50B44 Steel Seamless tube -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 50B44 Steel Seamless tube -:- For detailed product information, please contact sales. -:

Packing of AISI 50B44 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 566 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