AISI 8622 Steel Sheet,Plate

AISI 8622 Steel Sheet/Plate, heat treated, machined to 25 mm (1 in.) rounds, pseudocarburized, 775°C (1430°F) reheat, 150°C (300°F) temper Product Information -:- For detailed product information, please contact sales. -: AISI 8622 Steel Sheet/Plate, heat treated, machined to 25 mm (1 in.) rounds, pseudocarburized, 775°C (1430°F) reheat, 150°C (300°F) temper Synonyms -:- For detailed product information, please contact sales. -:

AISI 8622 Steel, heat treated, machined to 25 mm (1 in.) rounds, pseudocarburized, 775°C (1430°F) reheat, 150°C (300°F) temper Product Information -:- For detailed product information, please contact sales. -: ## **Product Specification: AISI 8622 Low-Alloy Steel - Simulated Core & Tempered Martensite Condition** ### **Product Designation** * **Standard Name:** AISI 8622 / SAE 8622 * **UNS Number:** G86220 * **Condition:** **Heat Treated, Machined, Pseudocarburized, Reheated & Tempered** * **Key Thermal Cycle:** 1. **Pseudocarburizing:** Simulated case-hardening thermal exposure (neutral atmosphere) 2. **Reheat:** **775°C (1430°F)** - Intercritical Anneal/Austenitization 3. **Final Temper:** **150°C (300°F)** - Low-Temperature Stress Relief * **Product Form:** **25 mm (1 inch) diameter round**, machined to final test specimen dimensions. * **Metallurgical State:** Represents a **refined, high-strength core microstructure** achievable after a specific heat treatment variant of a carburized part. ### **Overview** AISI 8622 is a low-carbon nickel-chromium-molybdenum steel, similar to 8620 but with slightly lower carbon for enhanced core toughness. The specified complex heat treatment creates a highly controlled material state for advanced engineering evaluation. Unlike a standard pseudocarburizing treatment that quenches directly from the high carburizing temperature, this process includes a **critical reheat to 775°C (1430°F)**. This temperature is typically within the **intercritical range** (ferrite + austenite phase field), allowing for refinement of the prior austenite grains and microstructure before final quenching and tempering. The result is a test material that provides data on a core with optimized strength-toughness balance for the highest-performance applications. --- ### **1. Chemical Composition (Typical % by Weight, AISI/SAE Standard)** | Element | Content (%) | Role & Effect | | :--- | :--- | :--- | | **Carbon (C)** | 0.20 - 0.25 | Slightly higher than 8620, providing a stronger core base while maintaining good toughness. | | **Manganese (Mn)** | 0.70 - 0.90 | Enhances hardenability. | | **Phosphorus (P)** | ≤ 0.035 | Impurity; kept low. | | **Sulfur (S)** | ≤ 0.040 | Impurity; kept low. | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer and solid solution strengthener. | | **Nickel (Ni)** | 0.40 - 0.70 | Improves core toughness and hardenability. | | **Chromium (Cr)** | 0.40 - 0.60 | Enhances hardenability and contributes to strength. | | **Molybdenum (Mo)** | 0.15 - 0.25 | Provides grain refinement, increases hardenability and tempering resistance. | | **Iron (Fe)** | Balance | | --- ### **2. Physical & Mechanical Properties (After Specified Thermal Cycle)** **A. Physical Properties (Estimated)** * **Density:** 7.85 g/cm³ * **Elastic Modulus (E):** ~205 GPa (29.7 x 10⁶ psi) **B. Mechanical Properties (Representative for this Specific Condition)** * **Process Sequence:** 1. Machine to 25 mm round test specimen. 2. **Pseudocarburize:** High-temperature soak (e.g., 925°C / 1700°F) to simulate carburizing cycle. 3. **Reheat to 775°C (1430°F):** This step **refines the microstructure**. It dissolves some carbides and creates a finer, more uniform austenite grain structure compared to the coarse grains from the pseudocarburizing step alone. 4. **Oil Quench** from 775°C. 5. **Temper at 150°C (300°F).** * **Core Hardness:** **45 - 52 HRC**. Higher than a standard pseudocarburized 8620 core due to the higher carbon content of 8622 and the refined martensite from the reheat. * **Ultimate Tensile Strength:** **1450 - 1650 MPa (210 - 239 ksi)** * **Yield Strength (0.2% Offset):** **1250 - 1450 MPa (181 - 210 ksi)** * **Elongation:** **~5 - 10%** * **Reduction of Area:** **~20 - 30%** * **Impact Toughness (Charpy V-notch):** **20 - 35 J (15 - 26 ft-lbf)**. **Expected to be superior** to a direct pseudocarburized & tempered condition due to the grain-refining effect of the 775°C reheat. * **Microstructure:** Fine, tempered martensite with a refined prior austenite grain size. --- ### **3. Product Applications** This is a **specialized test material condition** used for advanced research, development, and qualification of ultra-high-performance components. * **Aerospace & Defense Gear Development:** * **Process Optimization:** Studying the benefits of intercritical reheats (sometimes called "refine heats" or "intermediate quenching") on the core properties of critical gearing for helicopter transmissions and jet engine accessories. * **High-Cycle Fatigue Testing:** Generating core fatigue data (S-N curves) for components where weight savings demand the highest possible strength with adequate toughness. * **High-Performance Motorsports:** * **Material & Process Benchmarking:** Evaluating non-standard heat treatment cycles for transmission and differential gears in Formula 1, IndyCar, or endurance racing to push the limits of core performance. * **Advanced Bearing Research:** * **Core-Initiated Fatigue Studies:** Understanding failure mechanisms in large, heavily loaded bearings where core properties are limiting, and improved heat treatments are sought. * **Academic & Industrial Research:** * **Microstructure-Property Relationships:** Fundamental studies on the effect of intercritical heat treatments on the toughness of low-alloy steel martensite. --- ### **4. International Standards & Designations** | Standard System | Designation | Notes / Key Comparison | | :--- | :--- | :--- | | **SAE / AISI (USA)** | **SAE 8622** | The base grade designation. The thermal cycle is an experimental or proprietary specification. | | **UNS (USA)** | **G86220** | Unified Numbering System. | | **ASTM (USA)** | **ASTM A534** | Relevant standard for carburizing bearing steels, though this specific cycle is non-standard. | | **DIN / EN (Germany/EU)** | **~1.6523 (20NiCrMo2-2)** or **1.6562 (17NiCrMo6-4)** | Similar base grades. The 775°C reheat process may be analogous to a *"Zwischenstufenvergütung"* (intermediate quenching) practice. | | **JIS (Japan)** | **SNC822** | Similar Japanese grade. | | **GB (China)** | **20CrNiMo** or **22CrNiMo** | Similar Chinese grades. | --- ### **Technical Significance of the 775°C Reheat** 1. **Grain Refinement:** The primary purpose. Quenching directly from the pseudocarburizing temperature (~925°C) results in coarse prior austenite grains, which can harm toughness. The 775°C reheat starts from a finer, partially transformed structure, leading to a much finer final austenite grain size upon reheating. 2. **Carbide Modification:** Helps dissolve and redistribute coarse carbides that may have formed during the slow cool from the pseudocarburizing temperature or during the reheat itself. 3. **Strength/Toughness Optimization:** This specific thermal path aims to achieve a higher strength level than standard treatment while **preserving more toughness** than would be possible with a direct high-temperature quench and low temper. It represents a tailored, high-performance heat treatment strategy. ### **Summary** **AISI 8622 steel, processed to the specified "pseudocarburize + 775°C reheat + 150°C temper" condition in 25 mm rounds, represents a sophisticated, non-standard heat treatment state for advanced engineering evaluation.** It is not a commercial product but a **research and development artifact**. This process simulates an optimized core condition that prioritizes both high strength and improved toughness through microstructural refinement. Its use is confined to laboratories and qualification programs for the most demanding applications—such as aerospace gearing and elite motorsports—where incremental gains in core performance are critical and justify complex thermal processing. This condition highlights the nuanced interplay between heat treatment path and final properties in high-performance alloy steels. -:- For detailed product information, please contact sales. -: AISI 8622 Steel, heat treated, machined to 25 mm (1 in.) rounds, pseudocarburized, 775°C (1430°F) reheat, 150°C (300°F) temper Specification Dimensions Size： Diameter 20-1000 mm Length <4150 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 8622 Steel, heat treated, machined to 25 mm (1 in.) rounds, pseudocarburized, 775°C (1430°F) reheat, 150°C (300°F) temper Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 8622 Steel Sheet,Plate, heat treated, machined to 25 mm (1 in.) rounds, pseudocarburized, 775°C (1430°F) reheat, 150°C (300°F) temper -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 8622 Steel Sheet,Plate, heat treated, machined to 25 mm (1 in.) rounds, pseudocarburized, 775°C (1430°F) reheat, 150°C (300°F) temper -:- For detailed product information, please contact sales. -:

Packing of AISI 8622 Steel Sheet/Plate, heat treated, machined to 25 mm (1 in.) rounds, pseudocarburized, 775°C (1430°F) reheat, 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 Sheet/Plate 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 621 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