AISI 8620H Steel

AISI 8620H Steel Product Information -:- For detailed product information, please contact sales. -: AISI 8620H Steel Synonyms -:- For detailed product information, please contact sales. -:

AISI 8620H Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI 8620H Steel** #### **1. Overview** AISI 8620H is a **hardenability-controlled (H-grade)** variant of the widely used low-carbon nickel-chromium-molybdenum (Ni-Cr-Mo) alloy steel, standardized as a premium **case-hardening (carburizing) steel**. The "H" designation signifies that the material is produced to meet specific **end-quench (Jominy) hardenability requirements**, ensuring predictable and consistent transformation characteristics during heat treatment. This grade delivers superior **core property consistency** across production batches, making it the preferred choice for high-volume manufacturing of components requiring reliable and repeatable performance after carburizing. #### **2. International Standards & Designations** AISI 8620H is recognized under multiple international standards that specifically govern its hardenability characteristics. | Region/System | Standard Designation | Title / Purpose | | :--- | :--- | :--- | | **USA (AISI/SAE)** | **AISI 8620H, SAE J404 & SAE J1268** | Chemical Composition & Hardenability Bands | | **USA (ASTM)** | **ASTM A304** | Standard for Alloy Steel Bars Subject to End-Quench Hardenability Requirements | | **USA (ASTM)** | **ASTM A914/A914M** | Steel Bars Subject to Restricted Hardenability Bands (for specific applications) | | **UNS Number** | **H86200** | Unified Numbering System for H-Steels | | **Europe (EN)** | **1.6523H / 20NiCrMo2-2H** | Equivalent Hardenability-controlled Standard | | **Germany (DIN)** | **21NiCrMo2 H** | Hardenability-controlled Equivalent | | **Japan (JIS)** | **SNCM220H** | Equivalent Hardenability-controlled Grade | | **Hardenability Testing** | **ASTM A255** | Standard Test Methods for Determining Hardenability of Steel | #### **3. Chemical Composition & Hardenability Guarantee** The chemical composition range for 8620H is similar to standard 8620 but is more tightly controlled to ensure the hardenability consistently falls within the specified "H-band." **Core Composition (% by Weight, AISI 8620H):** | Element | Content Range | Metallurgical Role & H-Grade Significance | | :--- | :--- | :--- | | **Carbon (C)** | 0.17 - 0.23 | Provides base strength; tightly controlled to fine-tune hardenability within the H-band. | | **Manganese (Mn)** | 0.60 - 0.95 | **Primary hardenability control agent**; range adjusted to ensure the Jominy curve hits the specified band targets. | | **Phosphorus (P)** | ≤ 0.035 | Impurity; controlled to minimize brittleness. | | **Sulfur (S)** | ≤ 0.040 | Impurity; controlled for improved ductility and machinability. | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer; contributes to solid solution strengthening. | | **Nickel (Ni)** | 0.35 - 0.75 | Enhances core toughness; content is controlled to contribute to predictable hardenability. | | **Chromium (Cr)** | 0.35 - 0.65 | Increases hardenability and promotes carbide formation in the case; range optimized for band control. | | **Molybdenum (Mo)** | 0.15 - 0.25 | Strong hardenability agent; inhibits grain growth during carburizing, contributing to consistent response. | **Key Feature: Guaranteed Hardenability Band** The steel is purchased against a **certified range of hardness values at specific distances on the Jominy end-quench test bar**. This guarantees that the core hardness after carburizing and quenching will be **predictable and consistent**, regardless of the production heat or minor chemistry variations within the specified range. #### **4. Mechanical & Physical Properties** *Properties vary significantly with condition (annealed, normalized, heat-treated). The following are general characteristics, with the final properties being defined by the specific heat treatment applied.* **Typical Properties in Annealed Condition (Machining Stock):** * **Hardness:** 149 - 179 HB (Brinell) * **Tensile Strength:** 520 - 655 MPa (75 - 95 ksi) * **Yield Strength:** 385 - 515 MPa (56 - 75 ksi) * **Elongation:** 22% - 28% * **Machinability:** ~65% of B1112 steel (Good). **Properties After Case Hardening (Carburized & Hardened):** * **Surface Case Hardness:** **58 - 63 HRC** (Rockwell C) * **Core Hardness:** **25 - 45 HRC** (The **key advantage**: this range is narrow and predictable due to the H-band guarantee, typically varying by only ±3 HRC for a given section size). * **Core Strength & Toughness:** High and consistent, providing reliable support for the hard case. **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:** 12.5 x 10⁻⁶/°C (20-100°C) #### **5. Product Applications** AISI 8620H is specified for high-volume, critical components where **consistent performance, reduced scrap, and predictable heat treatment response** are essential. * **Automotive Transmission & Drivetrain:** High-volume production of gears, pinions, synchronizers, and shafts where every part must perform identically. * **Bearing Components:** Races and rollers for mass-produced bearings requiring uniform load capacity and fatigue life. * **Aerospace Components:** Gearing and actuator parts where material consistency is critical for certification and safety. * **Heavy Machinery:** Gears and shafts in construction and agricultural equipment produced in large batches. * **Fluid Power Systems:** Pump gears, hydraulic motor components, and valve parts for consistent performance. #### **6. Key Characteristics & Advantages of the H-Grade** * **Unmatched Core Property Consistency:** The primary reason for specifying 8620H. It eliminates batch-to-batch variation in core hardness and strength after quenching, ensuring uniform performance, fatigue life, and noise/vibration characteristics in assembled products like gearboxes. * **Reduced Production Scrap and Rework:** Virtually eliminates the risk of an entire heat of steel falling outside acceptable core hardness limits after heat treatment, a significant financial and logistical risk with standard grades. * **Optimized for Automated Manufacturing:** Predictable machinability and heat treatment response allow for optimized CNC machining parameters and heat treatment cycles, maximizing production efficiency and tool life. * **Enables Robust Design:** Allows engineers to design to tighter safety margins with confidence, knowing the material's response is guaranteed. * **Simplified Quality Control:** Reduces the amount of destructive testing required for lot acceptance, as the hardenability certification provides inherent assurance of final properties. **Conclusion:** **AISI 8620H is not merely a steel grade; it is a quality and consistency engineering solution.** While chemically similar to standard AISI 8620, the **"H" designation and its guaranteed hardenability band** provide a critical layer of process assurance that is invaluable for high-volume, precision manufacturing. It represents a strategic choice for manufacturers who prioritize **production yield, part-to-part consistency, and total cost of ownership** over simple material cost. For applications in the automotive, aerospace, and bearing industries—where thousands of identical components must perform reliably—8620H is the definitive material to minimize variability and maximize product reliability. -:- For detailed product information, please contact sales. -: AISI 8620H Steel Specification Dimensions Size： Diameter 20-1000 mm Length <5731 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 8620H Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 8620H Steel -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 8620H Steel -:- For detailed product information, please contact sales. -:

Packing of AISI 8620H Steel -:- 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 2202 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