AISI 8637H Steel Foil/Strip

AISI 8637H Steel Foil Product Information -:- For detailed product information, please contact sales. -: AISI 8637H Steel Foil Synonyms -:- For detailed product information, please contact sales. -:

AISI 8637H Steel Product Information -:- For detailed product information, please contact sales. -: ## **Product Introduction: AISI 8637H Steel** **AISI 8637H** is a **hardenability-controlled** variant of the nickel-chromium-molybdenum (Ni-Cr-Mo) low-alloy steel 8637. The critical **"H" designation** signifies that the steel is produced to guaranteed end-quench (Jominy) hardenability band requirements as per standards like SAE J1268. This ensures predictable and consistent depth of hardening regardless of normal melting variations, providing engineers and heat treaters with a material of superior reliability for critical components. The combination of medium carbon content and Ni-Cr-Mo alloying, now with guaranteed hardenability, makes 8637H a premium choice for applications demanding **maximum strength, toughness, and fatigue resistance in medium to heavy sections**. --- ### **1. Chemical Composition (Typical Weight %, AISI/SAE Standard)** The composition is balanced to achieve the guaranteed hardenability band, with permissible variations within ranges to meet this primary specification. | Element | Content Range | Metallurgical Function & H-Grade Significance | | :--- | :--- | :--- | | **Carbon (C)** | 0.35 – 0.40 | Provides base hardenability and strength. The "H" grade ensures the carbon content works synergistically with other elements to hit the target hardenability band. | | **Manganese (Mn)** | 0.75 – 1.00 | Key hardenability enhancer. Its level is carefully controlled to contribute to the guaranteed Jominy curve. | | **Phosphorus (P)** | ≤ 0.035 | Residual impurity (minimized). | | **Sulfur (S)** | ≤ 0.040 | Residual impurity (typically controlled for standard grades; may be modified in "H" grades to fine-tune hardenability or machinability). | | **Silicon (Si)** | 0.20 – 0.35 | Deoxidizer and ferrite strengthener. | | **Nickel (Ni)** | 0.40 – 0.70 | Improves core toughness and hardenability. Consistent Ni content is crucial for predictable hardenability. | | **Chromium (Cr)** | 0.40 – 0.60 | Enhances hardenability and wear resistance. A critical element for achieving the desired hardenability band. | | **Molybdenum (Mo)** | 0.15 – 0.25 | A potent hardenability agent for heavy sections; improves tempering resistance and prevents embrittlement. | **The "H"-Grade Distinction:** Unlike standard 8637, which is sold to chemical composition ranges only, **8637H is sold to a guaranteed hardenability band**. The chemical composition may vary from heat to heat within the specified ranges, but the final product is **certified** to fall within a standardized hardenability band (e.g., as defined in SAE J1268). This guarantees consistent performance in final heat treatment, especially in heavy sections where uniform through-hardening is critical. --- ### **2. Typical Physical & Mechanical Properties** Properties are highly dependent on the final heat treatment. The key advantage of the "H" grade is the consistency of these properties across production batches and within a part's cross-section. #### **A) As-Supplied Condition (Typically Annealed or Normalized)** *Optimal state for machining prior to final heat treatment.* * **Hardness (Annealed):** ~ 170 – 215 HBW * **Hardness (Normalized):** ~ 200 – 245 HBW * **Tensile Strength (Normalized):** 650 – 900 MPa (94 – 130 ksi) * **Yield Strength (Normalized):** 430 – 650 MPa (62 – 94 ksi) * **Machinability:** Good (in annealed condition). The uniform microstructure from proper annealing ensures consistent tool life. #### **B) After Quenching & Tempering (Representative Values)** *Example: Oil quenched, tempered at 540°C (1000°F). The "H" guarantee ensures minimal property gradient in specified sections.* * **Hardness:** 30 – 37 HRC (285 – 350 HBW) * **Tensile Strength:** 1000 – 1240 MPa (145 – 180 ksi) * **Yield Strength (0.2% Offset):** 900 – 1140 MPa (130 – 165 ksi) * **Elongation:** 14 – 19% * **Reduction of Area:** 45 – 55% * **Impact Toughness (Charpy V-notch):** 35 – 55 J (26 – 41 ft-lb) at room temperature. * **Guaranteed Hardenability:** Certified to a specific Jominy band (e.g., per SAE J1268). This ensures a known and consistent depth of hardness (e.g., capability to achieve a minimum hardness at a given Jominy distance). #### **C) General Physical Properties** * **Density:** 7.85 g/cm³ * **Modulus of Elasticity:** 205 GPa (29,700 ksi) * **Thermal Conductivity:** ~42 W/m·K (at 100°C) * **Thermal Expansion Coefficient:** ~11.5 µm/m·°C (20-100°C) --- ### **3. Key Features & Advantages** * **Guaranteed & Predictable Hardenability (Primary Advantage):** Eliminates the "heat treat lottery." Designers can confidently predict case depth and core properties, reducing scrap and ensuring performance in safety-critical parts. * **Excellent Through-Hardening Capacity:** The Ni-Cr-Mo-Base with H-control allows for uniform properties in sections where standard 8637 might show excessive softness at the core. * **Superior Strength-Toughness Balance:** Achieves high yield and tensile strength while maintaining good impact resistance, especially important for dynamically loaded components. * **Enhanced Fatigue Performance:** The consistent, fine-grained microstructure resulting from controlled hardenability contributes to high fatigue strength and endurance limits. * **Ideal for Heavy Sections:** The "H" guarantee makes it the preferred choice for larger-diameter shafts, gears, and rollers where core properties are as critical as surface hardness. * **Quality and Consistency:** Mandatory hardenability testing provides a higher level of quality assurance compared to standard grades. --- ### **4. Primary Applications** 8637H is specified for high-performance, safety-critical components where heat treatment consistency is non-negotiable. * **Automotive (Heavy-Duty & Performance):** * **Critical Gears:** Transmission and differential gears for heavy trucks and high-performance vehicles (often carburized). * **Axle & Drive Shafts:** Through-hardened axle shafts for severe service conditions. * **High-Strength Fasteners:** Engine bolts, cylinder head studs, and connecting rod bolts. * **Aerospace & Defense:** * Aircraft landing gear components (trunnions, links), engine mounts, and critical structural fittings where certification requires material consistency. * Rotor hub components and drive system parts. * **Heavy Machinery & Energy:** * **Large Gear Blanks:** For mining excavators, wind turbine gearboxes, and industrial reducers. * **Heavy-Duty Shafting:** Pump shafts, turbine shafts, and mill pinions. * **Oil & Gas:** Drill collar components, large-diameter tool joints, and high-pressure valve stems. * **Power Transmission:** * Large bearings, rolling mill rolls, and other components requiring deep, uniform hardness. --- ### **5. Relevant International Standards & Specifications** The "H" concept is primarily an AISI/SAE system. Other international standards achieve similar control through different means. | Region/System | Standard Number | Grade/Designation | Notes | | :--- | :--- | :--- | :--- | | **USA (AISI/SAE)** | **SAE J1268** | **Hardenability Bands** | The defining standard for "H" steel requirements. | | **USA (ASTM)** | **ASTM A304** | **8637H** | *The primary material specification for "H" steels*, covering bars subject to end-quench requirements. | | **USA (SAE)** | SAE J404 | 8637H | Lists chemical ranges. | | **USA (UNS)** | Unified Numbering System | **G86370H** | Unique identifier for the H-grade. | | **Germany/EU** | DIN EN 10083-3 | **34CrNiMo6 (+H)** | The nearest common equivalent. European standards do not use the "H" suffix; instead, **hardenability is typically specified by supplying Jominy test results or agreeing on specific mechanical property limits** for given sections. A material "34CrNiMo6" with an agreed hardenability range is the functional equivalent. | | **International (ISO)** | ISO 683-18 | - | Covers alloy steels for heat treatment; hardenability requirements are specified between purchaser and supplier. | | **Japan** | JIS G 4052 | **SCr440H** | Japanese hardenability-controlled alloy steel. **Not a direct equivalent** (different chemistry), but represents the same engineering philosophy of guaranteed hardenability. A closer match would be a hardenability-controlled version of SNC similar chemistry. | --- ### **6. Heat Treatment & Quality Assurance** * **Standard Heat Treatment:** Similar to 8637 (Austenitize: 830-855°C, Quench: Oil, Temper: As required). The process is more predictable and repeatable with 8637H. * **Mandatory Certification:** Each heat of 8637H must be accompanied by a **Jominy hardenability test report** showing the results fall within the specified band. * **Application in Design:** Engineers use the Jominy band data to calculate expected hardness at various depths in a part of a given diameter and quench severity, enabling precise design for performance. --- ### **Conclusion** **AISI 8637H steel** is not merely a material but a **performance assurance system**. It elevates the already-capable 8637 alloy by adding the crucial element of **guaranteed hardenability**. This makes it the unequivocal choice for manufacturers of high-value, safety-critical components—particularly in **automotive, aerospace, and heavy industry**—where consistent heat treatment response is vital for performance, safety, and cost control. By specifying 8637H, engineers design not just with material properties, but with **confidence in reproducible results**, ensuring that every finished part will perform as intended, batch after batch. It represents the optimal blend of performance, reliability, and engineering certainty for demanding applications. -:- For detailed product information, please contact sales. -: AISI 8637H Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6342 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 8637H Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 8637H Steel Foil -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 8637H Steel Foil -:- For detailed product information, please contact sales. -:

Packing of AISI 8637H 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 2813 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