1. Key Properties:
High Strength: SAE 8620 is a carburizing steel that provides excellent strength and wear resistance when heat-treated, making it ideal for applications that require high hardness at the surface and good core strength.
Good Toughness: Offers high toughness and impact resistance, even at lower temperatures, making it suitable for applications under dynamic or shock-loading conditions.
Good Machinability: SAE 8620 can be easily machined before heat treatment, enabling efficient fabrication for a wide variety of applications.
Excellent Hardening Properties: SAE 8620 responds well to carburizing and quenching, achieving a high-hardness surface for enhanced wear resistance while retaining a ductile and tough core.
Weldability: The material offers good weldability, but preheating and post-weld heat treatment may be necessary for thicker sections to ensure optimal properties.
Corrosion Resistance: It has moderate corrosion resistance, which can be improved by surface coatings or treatments.
2. Applications/Industries:
Automotive: SAE 8620 is widely used in automotive applications such as gears, shafts, and axles that require surface hardening and wear resistance, particularly in gearboxes, transmission parts, and drive components.
Heavy Machinery: Commonly used in manufacturing parts like shafts, gears, and crankshafts for heavy machinery and industrial equipment, where toughness and resistance to wear are critical.
Oil & Gas: Utilized in the oil and gas industry for producing durable components, including pump shafts, valves, and drilling tools, that must withstand high pressure and wear.
Aerospace: SAE 8620 is employed in aerospace parts, including landing gears and structural components that require a combination of high surface hardness and core toughness.
Military: Used in military applications such as armored vehicle parts and weapons systems, where high strength and resistance to fatigue and wear are essential.
3. Certifications/Standards:
SAE J403: SAE 8620 conforms to the SAE J403 standard for alloy steels, ensuring it meets chemical composition and mechanical property requirements.
ASTM A519: This standard applies to seamless carbon and alloy steel mechanical tubing, relevant for SAE 8620 seamless pipes.
ISO 9001: Quality management system certification.
4. Chemical Composition:
Carbon (C): 0.18% – 0.23%
Manganese (Mn): 0.60% – 0.90%
Chromium (Cr): 0.40% – 0.60%
Nickel (Ni): 0.70% – 1.00%
Molybdenum (Mo): 0.15% – 0.25%
Silicon (Si): 0.20% – 0.35%
Phosphorus (P): 0.035% max
Sulfur (S): 0.035% max
Iron (Fe): Balance
5. Technical Specifications:
Yield Strength:
SAE 8620: 460 MPa (minimum)
Tensile Strength:
SAE 8620: 655–830 MPa
Hardness:
SAE 8620: Approximately 200–250 HB (Brinell hardness) before heat treatment. After carburizing and quenching, the surface hardness can reach up to 60 HRC.