Introduction
Alloy steels contain a wide range of steels whose compositions exceed the limitations of C, Mo, Cr, Va, Mn, Ni, Si, and B fixed for carbon steels. These steels are more responsive to mechanical and heat treatments than carbon steels.
AISI 8620 alloy steel is a common, carburizing alloy steel. This alloy steel is flexible during hardening treatments, thus enabling improvement of case/core properties. The following datasheet will provide more details about AISI 8620 alloy steel.
Chemical Composition
The following table shows the chemical composition of AISI 8620 alloy steel.
| Element | Content (%) |
|---|---|
| Iron, Fe | 96.895-98.02 |
| Manganese, Mn | 0.700-0.900 |
| Nickel, Ni | 0.400-0.700 |
| Chromium, Cr | 0.400-0.600 |
| Carbon, C | 0.180-0.230 |
| Silicon, Si | 0.150-0.350 |
| Molybdenum, Mo | 0.150-0.250 |
| Sulfur, S | ≤ 0.0400 |
| Phosphorous, P | ≤ 0.0350 |
Physical Properties
The physical properties of AISI 8620 alloy steel are outlined in the following table.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm3 | 0.284 lb/in³ |
Mechanical Properties
The mechanical properties of annealed AISI 8620 alloy steel are outlined in the table below.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 530 MPa | 76900 psi |
| Yield strength | 385 MPa | 55800 psi |
| Elastic modulus | 190-210 GPa | 27557-30458 ksi |
| Bulk modulus (typical for steel) | 140 GPa | 20300 ksi |
| Shear modulus (typical for steel) | 80 GPa | 11600 ksi |
| Poisson’s ratio | 0.27-0.30 | 0.27-0.30 |
| Izod Impact | 115 J | 84.8 ft.lb |
| Hardness, Brinell | 149 | 149 |
| Hardness, Knoop (converted from Brinell hardness) | 169 | 169 |
| Hardness, Rockwell B (converted from Brinell hardness) | 80 | 80 |
| Hardness, Vickers (converted from Brinell hardness) | 155 | 155 |
| Machinability (hot rolled and cold drawn, based on 100 machinability for AISI 1212 steel) | 65 | 65 |
Thermal Properties
The thermal properties of AISI 8620 alloy steel are highlighted below.
| Properties | Metric | Imperial |
|---|---|---|
| Thermal conductivity | 46.6 W/mK | 323 BTU in/hr.ft².°F |
Other Designations
Equivalent materials to AISI 8620 alloy steel are outlined in the table below.
| AISI 8620 | AMS 6274 | AMS 6276 | AMS 6277 | AMS 6375 | ASTM A29 |
| ASTM A322 | ASTM A331 | ASTM A506 | ASTM A507 | ASTM A513 | ASTM A519 |
| ASTM A646 | ASTM A752 | ASTM A829 | MIL S-8690 | SAE J1397 | SAE J404 |
| AFNOR 20 NCD 2 | AFNOR 22 NCD 2 | DIN 1.6523 | UNI 20 NiCrMo 2 | JIS SNCM 21 | JIS SNCM 21 H |
| B.S. 805 H 20 | B.S. 805 M 20 | AMS 6274G | AMS 6276C | AMS 6277A | ASTM A505 |
| MIL SPEC MIL-S-16974 | SAE J404 | SAE J770 |
Applications
The AISI 8620 can be used for a number of medium-strength applications such as camshafts, fasteners, gears, and chains/chain pins.