AISI 8617H Steel, double quenched

AISI 8617H Steel, double quenched, 150°C (300°F) temper Product Information -:- For detailed product information, please contact sales. -: AISI 8617H Steel, double quenched, 150°C (300°F) temper Synonyms -:- For detailed product information, please contact sales. -:

AISI 8617H Steel, double quenched, 150°C (300°F) temper Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: AISI 8617H Steel, Double Quenched & 150°C (300°F) Tempered** ## **1. Overview** **AISI 8617H** is a hardenability-controlled (H-grade) low-carbon nickel-chromium-molybdenum alloy steel, specifically engineered for applications requiring precise and consistent through-hardening characteristics. The **"Double Quenched, 150°C (300°F) Temper"** represents an advanced thermal processing regimen that maximizes the steel's mechanical properties through microstructural refinement. This treatment involves **two sequential austenitizing and quenching operations** followed by a **low-temperature tempering process**, producing an ultra-fine martensitic structure with exceptional combinations of strength, toughness, and fatigue resistance. The "H" designation guarantees specific hardenability bands, ensuring consistent performance across production lots in demanding applications. ## **2. International Standards & Designations** AISI 8617H is governed by multiple international standards with specific hardenability requirements: | Standard System | Designation | Specification Focus | |----------------|-------------|---------------------| | **American (AISI/SAE)** | 8617H | Chemical composition and hardenability bands | | **ASTM** | A304 Grade 8617H | Standard for alloy steel bars subject to end-quench hardenability | | **UNS** | H86170 | Unified numbering system designation | | **SAE** | J1268 | Hardenability band specifications | | **Aerospace** | AMS 2300 | Premium aircraft-quality steel (cleanliness requirements) | | **European** | 1.6562 (18NiCrMo5) | Equivalent composition designation | **Heat Treatment Standards:** - **Double Quenching:** Typically specified in military/aerospace standards (e.g., **MIL-S-16974**) - **Tempering:** Governed by **ASTM A29/A29M** and **AMS 2759/1** (pyrometry requirements) - **Hardenability Testing:** **ASTM A255** (Standard Test Methods for Determining Hardenability of Steel) ## **3. Chemical Composition & Hardenability Characteristics** The "H" designation indicates guaranteed hardenability within specified bands, with chemistry controlled to ensure consistent Jominy curve performance. ### **Chemical Composition Range (Weight %):** | Element | Min | Max | Typical | |---------|-----|-----|---------| | **Carbon (C)** | 0.15 | 0.20 | 0.18 | | **Manganese (Mn)** | 0.70 | 0.90 | 0.80 | | **Phosphorus (P)** | - | 0.035 | 0.020 | | **Sulfur (S)** | - | 0.040 | 0.025 | | **Silicon (Si)** | 0.15 | 0.35 | 0.25 | | **Nickel (Ni)** | 0.40 | 0.70 | 0.55 | | **Chromium (Cr)** | 0.40 | 0.60 | 0.50 | | **Molybdenum (Mo)** | 0.15 | 0.25 | 0.20 | ### **Hardenability Bands (Jominy Test Data):** | Distance from Quenched End | HRC Range (Min-Max) | |----------------------------|---------------------| | **J1 (1/16")** | 42 - 50 | | **J4 (4/16")** | 38 - 47 | | **J8 (8/16")** | 32 - 42 | | **J12 (12/16")** | 28 - 38 | | **J20 (20/16")** | 25 - 35 | *The guaranteed hardenability ensures uniform properties in sections up to 75mm (3 inches) diameter.* ## **4. Mechanical Properties After Double Quench & 150°C Temper** The double quenching process provides grain refinement and complete austenite-to-martensite transformation, while the low-temperature temper relieves stresses while preserving high strength. ### **Typical Mechanical Properties:** *(For 25mm diameter bar, oil quenched)* | Property | Value Range | Typical | |----------|-------------|---------| | **Surface Hardness** | 52 - 55 HRC | 54 HRC | | **Core Hardness** (½ radius) | 50 - 53 HRC | 52 HRC | | **Ultimate Tensile Strength** | 1750 - 1950 MPa | 1850 MPa | | **Yield Strength (0.2% Offset)** | 1500 - 1700 MPa | 1600 MPa | | **Elongation at Break** | 9 - 13% | 11% | | **Reduction of Area** | 40 - 50% | 45% | | **Impact Toughness (Charpy V-notch, 20°C)** | 35 - 55 J | 45 J | | **Impact Toughness (Charpy V-notch, -40°C)** | 20 - 35 J | 28 J | | **Fatigue Strength (Rotating Bending)** | 700 - 800 MPa | 750 MPa | | **Fracture Toughness (K₁C)** | 55 - 75 MPa√m | 65 MPa√m | ### **Physical Properties:** | Property | Value | |----------|-------| | **Density** | 7.85 g/cm³ | | **Modulus of Elasticity** | 205 GPa | | **Shear Modulus** | 80 GPa | | **Poisson's Ratio** | 0.29 | | **Thermal Conductivity** (20°C) | 42.0 W/m·K | | **Specific Heat Capacity** | 460 J/kg·K | | **Thermal Expansion Coefficient** | 12.0 × 10⁻⁶/°C | ### **Double Quenching Process Details:** 1. **First Austenitize:** 8551°C (1575°F) ± 15°C, soak 30 min/inch, oil quench 2. **Second Austenitize:** 8301°C (1525°F) ± 15°C, soak 20 min/inch, oil quench 3. **Temper:** 150°C (300°F) ± 5°C for 2-3 hours 4. **Cooling:** Still air to room temperature *This process yields prior austenite grain size of ASTM 9-10, significantly finer than single-quench treatments.* ## **5. Product Applications** This specific heat treatment of AISI 8617H is employed in applications demanding the highest levels of strength, toughness, and reliability: ### **Critical Applications:** - **Aerospace Structural Components:** Aircraft landing gear parts, engine mounts, helicopter rotor components - **High-Performance Automotive:** Racing transmission gears, turbocharger shafts, performance valve train components - **Heavy Industrial Equipment:** Drill string components for oil/gas, large bearing races, hydraulic press components - **Defense Systems:** Firearm receivers (when through-hardening preferred), armored vehicle components - **Power Generation:** Turbine shafts, generator components subject to high cyclic stresses - **Precision Tooling:** Die components for cold working, high-strength fixtures and jigs ### **Design Considerations:** - Optimal for sections 12-75mm (0.5-3 inches) thickness - Particularly effective for components with varying cross-sections - Recommended for applications where distortion control is critical - Suitable for components requiring subsequent grinding or finishing operations ## **6. Key Characteristics & Advantages** ### **Metallurgical Advantages:** - **Ultra-Fine Grain Structure:** Double quenching produces ASTM 9-10 grain size, significantly enhancing toughness - **Complete Transformation:** Ensures minimal retained austenite (<3%) - **Uniform Hardness Profile:** H-grade chemistry provides consistent through-hardening - **Superior Fatigue Performance:** Fine grain structure and high compressive surface stresses enhance fatigue life ### **Processing Benefits:** - **Consistent Hardenability:** H-grade guarantee ensures predictable properties across production lots - **Reduced Distortion:** Second quench at lower temperature minimizes thermal stresses - **Improved Machinability (Pre-HT):** 85% of B1112 steel machinability in annealed condition - **Good Weldability:** With proper preheat (150-200°C) and post-weld tempering ### **Performance Comparison:** | Property | Single Quench & Temper | Double Quench & 150°C Temper | Improvement | |----------|-----------------------|------------------------------|-------------| | **Grain Size (ASTM)** | 6-7 | 9-10 | +3 grades finer | | **Impact Toughness** | 30-40 J | 40-55 J | +30-40% | | **Fatigue Limit** | 600-700 MPa | 700-800 MPa | +15-20% | | **Dimensional Stability** | Good | Excellent | Improved | | **Strength Uniformity** | Good | Superior | More consistent | ## **7. Quality Control & Testing Requirements** Components in this condition typically require: - **Hardenability Verification:** Jominy testing per ASTM A255 on each heat - **Microstructural Examination:** Per ASTM E112 (grain size), E45 (inclusion rating) - **Mechanical Testing:** Per ASTM A370 (tensile, impact) - **Non-Destructive Testing:** MPI per ASTM E1444 or FPI per ASTM E1417 - **Hardness Survey:** Multiple point verification to ensure uniformity - **Dimensional Inspection:** Post-heat treatment verification ## **Conclusion** **AISI 8617H Steel in the Double Quenched & 150°C (300°F) Tempered condition** represents the pinnacle of through-hardening alloy steel technology for critical engineering applications. The combination of **guaranteed hardenability (H-grade)** with **advanced double quenching heat treatment** produces a material with: 1. **Exceptional Strength-Toughness Balance:** 1850 MPa UTS with 45 J Charpy impact 2. **Superior Fatigue Resistance:** 750 MPa rotating bending fatigue limit 3. **Excellent Dimensional Stability:** Critical for precision components 4. **Consistent Performance:** H-grade chemistry ensures lot-to-lot uniformity This material is particularly valuable for **safety-critical applications** in aerospace, defense, and high-performance automotive sectors where component failure carries significant consequences. While more costly to process than conventional single-quench treatments, the **enhanced reliability and performance** justify the investment in applications where: - Maximum strength-to-weight ratio is required - Fatigue life is a primary design consideration - Consistent performance across production batches is essential - Fine surface finish and dimensional precision are needed after heat treatment Proper implementation requires careful attention to **process control, fixturing during heat treatment, and post-treatment inspection**, but delivers unparalleled performance in demanding service environments. -:- For detailed product information, please contact sales. -: AISI 8617H Steel, double quenched, 150°C (300°F) temper Specification Dimensions Size： Diameter 20-1000 mm Length <5707 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, double quenched, 150°C (300°F) temper Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 8617H Steel, double quenched, 150°C (300°F) temper -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 8617H Steel, double quenched, 150°C (300°F) temper -:- For detailed product information, please contact sales. -:

Packing of AISI 8617H Steel, double quenched, 150°C (300°F) temper -:- 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 2178 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