AISI 8620 Steel

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

AISI 8620 Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI 8620 Steel** #### **1. Overview** AISI 8620 is a versatile and widely used low-carbon **Nickel-Chromium-Molybdenum (Ni-Cr-Mo) alloy steel**, standardized by the American Iron and Steel Institute (AISI). It belongs to the family of **case-hardening (carburizing) steels**, renowned for its excellent combination of a **tough, ductile core** and the ability to develop an extremely **hard, wear-resistant surface** through carburizing or carbonitriding heat treatments. This balance of properties makes it a premier choice for high-strength, high-fatigue resistance components subject to surface wear and impact loading. #### **2. International Standards & Designations** AISI 8620 is recognized globally with numerous equivalent designations across different standard systems. | Region/System | Standard Designation | Title / Purpose | | :--- | :--- | :--- | | **USA (AISI/SAE)** | **AISI 8620, SAE J404** | Standard Chemical Composition | | **USA (ASTM)** | **ASTM A322** | Standard Specification for Steel Bars, Alloy, Standard Grades | | **USA (ASTM)** | **ASTM A534** | Carburizing Steels for Anti-Friction Bearings | | **UNS Number** | **G86200** | Unified Numbering System | | **Europe (EN)** | **1.6523 / 20NiCrMo2-2** | Equivalent Material Standard | | **Germany (DIN/W-Nr.)** | **21NiCrMo2 / 1.6523** | Equivalent Designation | | **Japan (JIS)** | **SNCM220** | Equivalent Material Standard | | **International (ISO)** | **ISO 683-11: 20NiCrMo2-2** | International Standard | #### **3. Chemical Composition** The alloy composition is precisely balanced to provide good core hardenability and toughness, while remaining responsive to surface carburizing. | Element | Content (% by Weight) | Metallurgical Role | | :--- | :--- | :--- | | **Carbon (C)** | 0.18 - 0.23 | Provides core strength; low enough for good case/core property differential after carburizing. | | **Manganese (Mn)** | 0.70 - 0.90 | Increases hardenability, aids in deoxidation. | | **Phosphorus (P)** | ≤ 0.035 | Impurity; controlled to minimize brittleness. | | **Sulfur (S)** | ≤ 0.040 | Impurity; controlled for improved ductility and transverse properties. | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer, increases strength. | | **Nickel (Ni)** | 0.40 - 0.70 | **Key Element:** Significantly enhances core toughness and hardenability. | | **Chromium (Cr)** | 0.40 - 0.60 | Increases hardenability, promotes formation of hard carbides in the case, improves wear resistance. | | **Molybdenum (Mo)** | 0.15 - 0.25 | Enhances hardenability, increases strength at high temperatures, reduces risk of temper embrittlement, refines grain structure. | | **Iron (Fe)** | Balance | Base metal. | #### **4. Mechanical & Physical Properties** *Properties vary significantly with the condition (annealed, normalized, heat-treated). The following are general characteristics.* **Typical Properties in Annealed/Normalized Condition (Machining Stock):** * **Hardness:** 149 - 217 HB (Brinell) * **Tensile Strength:** 520 - 795 MPa (75 - 115 ksi) * **Yield Strength:** 385 - 585 MPa (56 - 85 ksi) * **Elongation:** 18% - 28% * **Machinability:** ~65% of B1112 steel (Good in annealed condition). **Properties After Case Hardening (Carburized & Hardened):** * **Surface Case Hardness:** **58 - 63 HRC** (Rockwell C) * **Effective Case Depth:** Typically 0.5 - 2.0 mm (0.020" - 0.080"), adjustable per process. * **Core Hardness:** **25 - 45 HRC**, depending on section size and quench. * **Core Tensile Strength:** ~700 - 1200 MPa (100 - 175 ksi) * **Excellent Bending & Contact Fatigue Resistance.** **Physical Properties:** * **Density:** 7.85 g/cm³ (0.284 lb/in³) * **Modulus of Elasticity:** 205 GPa (29,700 ksi) * **Poisson's Ratio:** 0.29 * **Thermal Conductivity:** ~45 W/m·K * **Coefficient of Thermal Expansion:** 12.5 x 10⁻⁶/°C (20-100°C) #### **5. Product Applications** AISI 8620 is a workhorse material across industries where components require a hard, wear-resistant surface and a shock-absorbing core. * **Automotive:** Gears (transmission, differential), pinions, camshafts, crankshafts, piston pins, shafts, and bearings. * **Aerospace:** Gearing, landing gear components, actuator parts, and fasteners. * **Heavy Machinery & Equipment:** Gears, shafts, rollers, sprockets, and chain links for construction, mining, and agricultural machinery. * **Oil & Gas:** Downhole tool components, valve parts, pump gears. * **Industrial Power Transmission:** Gearbox components, heavy-duty bearings, couplings. * **General Engineering:** Pins, bushings, and fixtures that undergo surface wear. #### **6. Key Characteristics & Advantages** * **Superior Core Toughness:** The nickel content provides exceptional impact and fatigue resistance in the component's core, preventing catastrophic failure under heavy or shock loads. * **Excellent Hardenability:** The balanced Cr, Mo, and Ni alloying allows for good through-hardening of the core and the formation of a deep, hard case. * **Good Wear & Pitting Resistance:** The hard, carburized surface effectively resists abrasion and surface fatigue (pitting). * **Good Machinability (in annealed state):** Can be readily machined into complex shapes prior to heat treatment. * **Weldability:** Fair to good with proper preheat and post-weld heat treatment procedures. * **Versatility in Heat Treatment:** Can be processed via various methods: direct quench, single quench, or double quench (reheat and quench) for optimal distortion control and property balance. **Conclusion:** **AISI 8620 is a foundational and highly reliable case-hardening alloy steel.** Its well-understood behavior, excellent balance of core toughness and surface hardness, and widespread availability make it a default choice for a vast array of critical, heavily loaded mechanical components. From the gears in a family car to the transmissions in heavy mining trucks, AISI 8620 provides the durable, fatigue-resistant performance that modern machinery relies upon. Its success lies in its predictable response to heat treatment and its cost-effective performance in demanding applications. -:- For detailed product information, please contact sales. -: AISI 8620 Steel Specification Dimensions Size： Diameter 20-1000 mm Length <5713 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 8620 Steel Properties -:- For detailed product information, please contact sales. -:

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

Packing of AISI 8620 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 2184 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