AISI 8617H Steel, heat treated, machined, pseudocarburized

AISI 8617H Steel, heat treated, machined, pseudocarburized Product Information -:- For detailed product information, please contact sales. -: AISI 8617H Steel, heat treated, machined, pseudocarburized Synonyms -:- For detailed product information, please contact sales. -:

AISI 8617H Steel, heat treated, machined, pseudocarburized Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI 8617H Steel, Heat Treated, Machined, and Pseudocarburized** #### **1. Overview** AISI 8617H is a **hardenability-controlled (H-band)** version of the low-carbon nickel-chromium-molybdenum alloy steel AISI 8617. The process described—**"Heat Treated, Machined, and Pseudocarburized"**—represents a specialized and advanced material preparation protocol for critical components. This involves: 1. **Heat Treatment (Core Hardening):** Through-hardening to develop a strong, tough core microstructure. 2. **Machining:** Precision machining of the component to its final geometry in the heat-treated state. 3. **Pseudocarburizing:** A simulated carburizing thermal cycle in a neutral atmosphere (no carbon addition) to stabilize the microstructure and stress state *without* altering surface chemistry. This combination yields a component with **high and uniform core strength, excellent dimensional stability, and a stress-relieved condition**, ready for final surface hardening (like induction or nitriding) or for use in applications where a deep, wear-resistant case is not required but core properties are paramount. #### **2. International Standards & Designations** AISI 8617H is defined by several key standards that govern its composition, hardenability, and processing: | Category | Standard | Purpose | | :--- | :--- | :--- | | **Material Designation** | **AISI 8617H**, **SAE J1268** (H-Steel Hardenability Bands) | Defines the chemical composition and Jominy hardenability band. | | **Material Specification** | **ASTM A304** (Standard Specification for Carbon and Alloy Steel Bars Subject to End-Quench Hardenability Requirements) | The primary governing specification for procurement. | | **Heat Treatment** | **AMS 2759/1** (Pyrometry), **SAE AMS-H-6875** (Heat Treatment of Steels) | Guidelines for controlled atmosphere heat treatment. | | **Pseudocarburizing** | Common industry practice; often referenced in internal aerospace/automotive specifications (e.g., **GE S400**, **Boeing BAC 5621**). | Defines the thermal cycle for microstructure stabilization. | #### **3. Chemical Composition & Hardenability (H-Band)** The "H" designation ensures the steel's hardenability falls within a specified range, guaranteeing consistent core properties after heat treatment across different production lots. **Chemical Composition Range (Weight %, AISI 8617H):** | Element | Content Range | | :--- | :--- | | Carbon (C) | 0.15 - 0.20 | | Manganese (Mn) | 0.70 - 0.90 | | Phosphorus (P) | ≤ 0.035 | | Sulfur (S) | ≤ 0.040 | | Silicon (Si) | 0.15 - 0.35 | | Nickel (Ni) | 0.40 - 0.70 | | Chromium (Cr) | 0.40 - 0.60 | | Molybdenum (Mo) | 0.15 - 0.25 | **Key Feature: Guaranteed Hardenability Band** The core hardness after quenching is predictable. At the standard Jominy distances (e.g., J4, J8, J12), the hardness will fall within the published SAE H-band range for 8617H, ensuring reproducible core strength in final parts. #### **4. Mechanical & Physical Properties (After Processing)** The final properties are a result of the combined core hardening and pseudocarburizing cycle. **Typical Core Properties (After Heat Treat & Pseudocarburize):** * **Core Hardness:** 36 - 42 HRC (Typical aim ~38-40 HRC) * **Ultimate Tensile Strength:** 1150 - 1300 MPa (167 - 189 ksi) * **Yield Strength (0.2% Offset):** 950 - 1100 MPa (138 - 160 ksi) * **Elongation:** 12% - 16% * **Reduction of Area:** 50% - 60% * **Impact Toughness (Charpy V-notch):** 50 - 80 J (37 - 59 ft-lbf) – High due to nickel content and fine temper structure. **Physical Properties:** * Density: 7.85 g/cm³ (0.284 lb/in³) * Modulus of Elasticity: 205 GPa (29,700 ksi) * Poisson's Ratio: 0.29 * Coefficient of Thermal Expansion: 12.2 x 10⁻⁶/°C (20-100°C) #### **5. Product Applications** This specific processed form of AISI 8617H is used for high-integrity components where dimensional precision, core strength, and fatigue performance are more critical than a thick carburized case. * **Precision Gears (Subsequent Surface Hardened):** High-performance transmission gears that undergo final **induction hardening** or **gas nitriding** after this process. The stable core provides excellent support for the thin, hard surface layer. * **Aerospace Actuator Components:** Ball screws, shafting, and linkage parts requiring high strength, good toughness, and minimal distortion. * **Hydraulic & Pneumatic Components:** High-pressure piston rods, cylinders, and valve bodies where through-hardening provides uniform strength. * **Bearings & Races (for specialized designs):** Components where core strength and dimensional stability under load are the primary design drivers. * **Tooling & Fixtures:** Jigs, fixtures, and die components that require high strength, good machinability after heat treatment, and long-term dimensional stability. #### **6. Key Characteristics & Advantages** * **Exceptional Dimensional Stability:** Machining *after* core hardening and *before* pseudocarburizing minimizes final distortion. The pseudocarburizing cycle acts as a final stress relief. * **Predictable & Uniform Core Properties:** The **H-band guarantee** ensures consistent mechanical properties part-to-part and batch-to-batch. * **Excellent Machinability (in Hardened State):** For a through-hardened steel in the 36-42 HRC range, it maintains relatively good machinability with appropriate tooling (ceramic or CBN inserts), allowing for precision finishing. * **Superior Fatigue Strength:** The fine-tempered martensitic core microstructure, combined with compressive surface stresses from machining and thermal cycling, results in excellent bending and torsional fatigue resistance. * **Ready for Final Surface Engineering:** The pseudocarburized state provides a stable, decarburization-free surface ideal for subsequent localized hardening processes (induction, laser) or coating applications. * **Cost-Effective for Complex Geometries:** This process flow can be more economical than carburizing and then machining extremely hard (60+ HRC) surfaces, especially for complex parts with tight tolerances. **Conclusion:** **AISI 8617H in the Heat Treated, Machined, and Pseudocarburized condition** is a sophisticated engineering material solution tailored for the most demanding **high-precision, high-strength applications**. It transcends the traditional role of 8617 as merely a carburizing steel, leveraging its excellent core hardenability and alloy design to create components where **bulk properties, dimensional accuracy, and microstructural stability are paramount.** This makes it a preferred choice in advanced aerospace, motorsport, and high-performance industrial systems where reliability is built upon predictable material performance and precision manufacturing. -:- For detailed product information, please contact sales. -: AISI 8617H Steel, heat treated, machined, pseudocarburized Specification Dimensions Size： Diameter 20-1000 mm Length <5706 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 8617H Steel, heat treated, machined, pseudocarburized Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 8617H Steel, heat treated, machined, pseudocarburized -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 8617H Steel, heat treated, machined, pseudocarburized -:- For detailed product information, please contact sales. -:

Packing of AISI 8617H Steel, heat treated, machined, pseudocarburized -:- 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 2177 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