AISI 6118H Steel Foil/Strip

AISI 6118H Steel Foil Product Information -:- For detailed product information, please contact sales. -: AISI 6118H Steel Foil Synonyms -:- For detailed product information, please contact sales. -:

AISI 6118H Steel Product Information -:- For detailed product information, please contact sales. -: ## **Product Introduction: AISI 6118H Controlled Hardenability Case-Hardening Steel** **Overview** AISI 6118H is the **hardenability-controlled variant** of AISI 6118, a chromium-vanadium case-hardening steel specifically engineered for applications requiring **predictable and consistent heat treatment response**. The "H" designation indicates the steel is produced to meet specific hardenability band requirements as defined by ASTM standards. This ensures more uniform core properties and case depth consistency in mass production, particularly for critical automotive and heavy machinery components. Like its 6118 counterpart, it is designed for carburizing processes that create a hard, wear-resistant surface while maintaining a tough, ductile core. --- ### **1. Chemical Composition (Range by Weight %, ASTM A304)** The chemical composition of 6118H is essentially identical to standard 6118 but with tighter controls to ensure consistent hardenability. The "H" grade allows for slightly adjusted element ranges to achieve the required hardenability band. | Element | 6118H Range (%) | Role & Effect | | :--- | :--- | :--- | | **Carbon (C)** | 0.16 - 0.21 | Provides base strength; optimized for core toughness after carburizing. | | **Manganese (Mn)** | 0.55 - 0.80 | Primary hardenability agent; range adjusted to control Jominy hardenability band. | | **Phosphorus (P)** | ≤ 0.030 | Impurity; controlled at lower levels for improved consistency. | | **Sulfur (S)** | 0.08 - 0.13 | **Intentionally added** to improve machinability (resulturized grade). | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer and solid solution strengthener. | | **Chromium (Cr)** | 0.50 - 0.80 | Enhances hardenability and promotes hard carbides in the case; range may be wider than standard 6118. | | **Vanadium (V)** | 0.10 - 0.15 | Grain refiner; prevents grain growth during carburizing for improved toughness. | | **Iron (Fe)** | Balance | | *Key Difference from 6118: While the nominal chemistry is similar, 6118H is purchased based on its **guaranteed hardenability band** (per ASTM A304), not just chemical ranges. Multiple heats of 6118H can be blended to achieve this consistency.* --- ### **2. Physical & Mechanical Properties** **A. Physical Properties (Annealed State)** * **Density:** 7.85 g/cm³ (0.284 lb/in³) * **Elastic Modulus:** ~205 GPa (29.7 x 10⁶ psi) * **Poisson's Ratio:** 0.29 * **Thermal Conductivity:** ~52 W/m·K * **Coefficient of Thermal Expansion:** 11.5 x 10⁻⁶ /K (20-100°C) **B. Hardenability Data (Core Properties - Jominy Test)** * **Standard:** ASTM A304 * **Hardenability Band:** Defined by "H" designation. 6118H will have a specified range of Rockwell hardness values at standard distances (e.g., J1, J5, J10, J20 etc.) from the quenched end of a Jominy bar. * **Typical Jominy Curve Position:** Provides moderate hardenability suitable for medium-section parts (e.g., gear teeth up to ~50-75 mm in diameter). **C. Mechanical Properties (After Carburizing & Heat Treatment)** *Note: Final properties depend on section size and heat treatment details.* * **Surface Hardness (Case):** 58 - 63 HRC (after carburizing, quenching & tempering) * **Effective Case Depth:** Typically 0.5 - 2.0 mm (0.020 - 0.080 inches) * **Core Hardness:** 30 - 42 HRC (provides optimal strength-toughness balance) * **Core Tensile Strength:** 700 - 1000 MPa (102 - 145 ksi) * **Core Yield Strength:** 550 - 850 MPa (80 - 123 ksi) * **Core Elongation:** ≥ 12% * **Impact Strength (Charpy V-notch, Core):** Excellent due to fine-grained, tough core microstructure. --- ### **3. Product Applications** AISI 6118H is specified for high-volume, critical components where **heat treatment consistency and part-to-part reliability are paramount**. Its applications are more specialized than standard 6118 due to the premium for hardenability control. * **Automotive Powertrain (Primary Market):** * **Critical Gears:** Transmission gears (synchro hubs, shafts), differential gears and pinions, transfer case gears. * **Shafting:** High-torque axle shafts, drive shafts, output shafts. * **Engine Components:** High-performance camshafts, followers. * **Heavy-Duty & Off-Highway Vehicles:** * Powertrain gears for trucks, bulldozers, and agricultural machinery. * Final drive pinions and planet gears. * **Industrial Gearboxes:** * High-load, high-cycle gears in standardized gearboxes where predictable performance is critical. * **Aerospace Actuation Systems:** * Gears and shafts in flight control actuators requiring certified material consistency. --- ### **4. International Standards & Designations** The "H" concept is primarily a North American (SAE/ASTM) system. True direct equivalents are rare, as other standards systems often specify hardenability differently (e.g., by steel grade selection and quenching methods). | Standard System | Designation | Notes / Key Comparison | | :--- | :--- | :--- | | **SAE / AISI (USA)** | **SAE 6118H** | The standard "H"-grade designation. | | **ASTM (USA)** | **ASTM A304** (G61180H) | Governing standard for H-band hardenability requirements. Also covered under **ASTM A914** for steel bars. | | **UNS (USA)** | **G61180H** | Unified Numbering System equivalent. | | **DIN / EN (Germany/EU)** | **No direct H-equivalent** | The functional approach would be to specify a steel like **1.7131 (16MnCr5)** with additional grain refinement (Al-treatment) and hardenability verification (e.g., +HH option for through-hardening steels, but not directly applicable to case-hardening grades). | | **JIS (Japan)** | **No direct equivalent** | Similar case-hardening grades exist (SCM420H, SMn420H) but with different alloying bases. The "H" suffix in JIS can denote boron-treated steels, causing confusion. | | **GB (China)** | **No direct equivalent** | Similar grades like 20CrMnTiH exist, where "H" indicates a hardenability-specified variant, but chemistry differs significantly. | **Procurement Note:** 6118H is ordered by specifying the **SAE grade (6118H)** and requiring certification to **ASTM A304**, which includes the actual Jominy hardenability test report showing the lot conforms to the published hardenability band for 6118H. --- ### **Summary** AISI 6118H represents the **premium, consistency-focused version** of 6118 steel. By guaranteeing a specific hardenability band, it ensures: 1. **Uniform core hardness and strength** across different production batches and part sections. 2. **Predictable case depth penetration** during carburizing. 3. **Reduced heat treatment distortion and variability.** This makes it the material of choice for high-volume manufacturing of safety-critical and performance-critical powertrain components, where predictable mechanical behavior and long-term reliability outweigh the slight cost premium over standard 6118. It exemplifies the application of statistical process control to alloy steel production for advanced manufacturing. -:- For detailed product information, please contact sales. -: AISI 6118H Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4135 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 6118H Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 6118H Steel Foil -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 6118H Steel Foil -:- For detailed product information, please contact sales. -:

Packing of AISI 6118H Steel Foil/Strip -:- 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 Foil/Strip 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 606 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