Latrobe,CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel Tube,Pipe

Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel Tube Product Information -:- For detailed product information, please contact sales. -: Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel Tube Synonyms -:- For detailed product information, please contact sales. -:

Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Datasheet: Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel** #### **1. Product Overview** Latrobe’s **CBS-50™ NiL (Case-Hardened Bearing Steel - Nickel Low)** is a premium, deep-case carburizing steel produced via advanced **Vacuum Induction Melting (VIM)** followed by **Vacuum Arc Remelting (VAR)**. It represents a significant evolution beyond M50 steel, specifically engineered to overcome the limitations of through-hardened grades by offering a superior combination of a **very hard, wear-resistant surface** and an **exceptionally tough, ductile core**. This unique property profile, achieved through carburizing heat treatment, makes it the material of choice for the most demanding, heavy-duty aerospace bearings and transmission gears subject to high contact stresses, shock loads, and rolling contact fatigue. #### **2. Key Advantages & Characteristics** * **Unmatched Combination of Surface & Core Properties:** Provides a case hardness of 58-64 HRC for wear resistance, with a tough, ductile core (typically 40-48 HRC) to absorb high impact and bending stresses. * **Superior Rolling Contact Fatigue (RCF) & Bending Fatigue Life:** Demonstrates significantly longer fatigue life compared to through-hardened steels in heavily loaded applications, particularly where sub-surface initiated spalling is a concern. * **Enhanced Fracture Toughness:** The nickel-alloyed, low-carbon martensitic core offers excellent fracture toughness and resistance to crack propagation. * **Exceptional Steel Cleanliness:** The dual VIM-VAR melting process ensures ultra-low levels of non-metallic inclusions, which are critical initiators of fatigue failure in high-cycle applications. * **Deep & Controllable Case Depth:** Capable of achieving deep, uniform case depths (typically >2.5 mm / 0.100") for large, heavily loaded components like main shaft bearings and planetary gears. * **Good Dimensional Stability:** Exhibits lower distortion during the carburizing and quenching process compared to some alloy steels, owing to its fine, homogeneous microstructure. #### **3. Chemical Composition (Typical, wt.%)** The composition is optimized for deep hardenability, core toughness, and response to carburizing. | Element | Content Range (Typical) | Metallurgical Function | | :--- | :--- | :--- | | **Carbon (C)** | 0.10 - 0.15 | Provides core strength and hardenability; surface carbon enriched during carburizing. | | **Nickel (Ni)** | 2.75 - 3.25 | **Key alloy:** Dramatically increases core toughness, ductility, and hardenability. Improves low-temperature properties. | | **Chromium (Cr)** | 3.75 - 4.25 | Provides hardenability and forms stable carbides in the case for wear resistance. | | **Molybdenum (Mo)** | 3.90 - 4.40 | Enhances hardenability, promotes secondary hardening, refines grain structure. | | **Vanadium (V)** | 0.90 - 1.10 | Forms fine, hard vanadium carbides for grain refinement and improved wear resistance. | | **Manganese (Mn)** | 0.20 - 0.40 | Aids hardenability and acts as a deoxidizer. | | **Silicon (Si)** | 0.20 - 0.40 | Deoxidizer, strengthens the ferrite matrix. | | **Sulfur (S)** | ≤ 0.005 | Ultra-low to maximize transverse properties and cleanliness. | | **Phosphorus (P)** | ≤ 0.010 | Ultra-low impurity control. | | **Iron (Fe)** | Balance | Matrix. | *Note: The VIM-VAR process ensures oxygen levels typically <10 ppm and hydrogen <2 ppm.* #### **4. Physical & Mechanical Properties** *Properties are highly dependent on the carburizing cycle and final heat treatment.* **A. Core Properties (After Carburizing & Heat Treatment):** * **Core Hardness:** 40 - 48 HRC (typical, varies with tempering temperature) * **Ultimate Tensile Strength:** 1240 - 1520 MPa (180 - 220 ksi) * **Yield Strength (0.2% Offset):** 1035 - 1380 MPa (150 - 200 ksi) * **Elongation:** 10 - 15% * **Reduction in Area:** 35 - 55% * **Fracture Toughness (K_IC):** **25 - 35 MPa√m** (Significantly higher than through-hardened M50) **B. Case Properties:** * **Surface Hardness:** 58 - 64 HRC (after carburizing, quenching, and tempering) * **Effective Case Depth:** Customizable; typically >2.5 mm (0.100") to 4.0 mm (0.160") at 50 HRC. * **Residual Stress:** High compressive stresses at the surface, enhancing fatigue life. **C. Physical Properties:** * **Density:** ~7.78 g/cm³ * **Modulus of Elasticity:** ~205 GPa * **Thermal Expansion Coefficient:** ~11.5 x 10^-6 /°C (20-100°C) #### **5. International Standards & Specifications** CBS-50™ NiL is a proprietary, premium-grade material with equivalents in various standards. * **Primary Specifications:** * **AMS 6281:** The primary Aerospace Material Specification for this grade of steel (Carburizing, VIM-VAR). * **AMS 2301:** Aircraft Quality Steel Cleanliness (Premium, typically Special Electron Beam Remelted grade). * **AMS 2759/3:** Heat Treatment of Steel Parts, Carburizing and Hardening. * **Cross-References / Similar Grades:** * **AISI/SAE:** Similar in concept to a modified **9310** but with higher Cr, Mo, V for superior high-temperature performance. * **European (DIN/WNr):** Conceptually similar to high-performance case-hardening steels like **1.6587** but with distinct chemistry. * **Latrobe Proprietary Designation:** **CBS-50™ NiL VIM-VAR**. * **Key Industry Standards:** Compliant with **AS9100** for aerospace and applicable sections of **ARP 1820** for gear materials. #### **6. Product Applications** CBS-50™ NiL is specified for the most critical, high-integrity components in aerospace and power transmission. * **Aerospace Turbine Engines:** Main shaft bearings, planetary gears in gearboxes, fan drive gear system (FDGS) components, accessory drive gears. * **Aerospace Transmissions:** Helicopter main and tail rotor gearbox bearings and gears. * **Advanced Rotorcraft:** Tiltrotor proprotor gearbox components. * **Industrial Gas Turbines:** Heavy-duty power generation turbine bearings and drive train gears. * **High-Performance Racing & Defense:** Critical gears and bearings in applications where weight, reliability, and extreme load capacity are paramount. #### **7. Heat Treatment Process** The performance of CBS-50™ NiL is realized through a precise, multi-step thermal process: 1. **Carburizing:** Typically performed via vacuum carburizing or atmospheric gas carburizing at 925-980°C to achieve the desired case depth and surface carbon concentration (~0.8-1.0%). 2. **Diffusion:** A hold at temperature to allow carbon to diffuse inward, creating a smooth gradient. 3. **Quenching:** Oil quenching from the austenitizing temperature (typically 1040-1095°C) to transform both case and core to martensite. 4. **Sub-Zero Treatment:** Often employed to transform retained austenite in the high-carbon case to martensite. 5. **Tempering:** Multiple tempers (typically 2-3 cycles) at 150-200°C to relieve stresses and achieve final hardness in both case and core. --- **Disclaimer:** This datasheet provides general information based on typical industry data for CBS-50™ NiL-type materials. Latrobe Specialty Metals’ exact specifications, processing guidelines, and certified properties may vary. The performance of a finished component is critically dependent on part geometry, precise heat treatment parameters, and manufacturing controls. For all critical applications, **direct consultation with Latrobe’s technical and engineering team is essential** for material selection, specification, and validation. -:- For detailed product information, please contact sales. -: Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel Specification Dimensions Size： Diameter 20-1000 mm Length <5323 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. -: Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel Tube -:- For detailed product information, please contact sales. -: Chemical Identifiers Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel Tube -:- For detailed product information, please contact sales. -:

Packing of Latrobe CBS-50™ NiL VIM-VAR High Performance Carburizing Bearing and Gear Steel 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 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 1794 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