Carbon steels are a category of steels with 0.12 to 2% carbon content. AISI 1045 is a medium carbon steel designed to be able to function in areas requiring greater strength and hardness. This steel possesses excellent size accuracy, concentricity, and straightness which together enable to minimize wear in high speed applications. AISI 1045 can be formed into turned, ground and polished bars that can be machined unsymmetrically with limited distortion.
The following sections will discuss in detail about AISI 1045 carbon steel.
Chemical Composition
The chemical composition of AISI 1045 carbon steel is outlined in the following table.
| Element | Content (%) |
| Carbon, C | 0.43-0.50 |
| Manganese, Mn | 0.60-0.90 |
| Sulfur, S | 0.05 (max) |
| Phosphorous, P | 0.04 (max) |
| Iron, Fe | Balance |
Physical Properties
The physical properties of AISI 1045 carbon steel are tabulated below.
| Properties | Metric | Imperial |
| Density | 7.87 g/cm3 | 0.284 lb/in3 |
Mechanical Properties
The following table shows mechanical properties of cold rolled AISI 1045 carbon steel.
| Properties | Metric | Imperial |
| Tensile strength | 585 MPa | 84800 psi |
| Yield strength | 450 MPa | 65300 psi |
| Modulus of elasticity | 200 GPa | 29000 ksi |
| Shear modulus (typical for steel) | 80 GPa | 11600 ksi |
| Poisson’s ratio | 0.29 | 0.29 |
| Elongation at break (in 50 mm) | 12 % | 12 % |
| Hardness, Brinell | 163 | 163 |
| Hardness, Knoop (converted from Brinell hardness) | 184 | 184 |
| Hardness, Rockwell B (converted from Brinell hardness) | 84 | 84 |
| Hardness, Vickers (converted from Brinell hardness) | 170 | 170 |
Thermal Properties
The thermal properties of cold drawn AISI 1045 carbon steel are given in the following table.
| Properties | Metric | Imperial |
| Thermal conductivity | 51.9 W/mK | 360 BTU in/hr.ft2.°F |
| Thermal expansion co-efficient (@0.000-100°C/32-212°F) | 11.2 µm/m°C | 6.22 µm/m°C |
Other Designations
Other designations that are equivalent to AISI 1045 carbon steel include the following.
| AFNOR XC 42 TS | AFNOR XC 45 | AFNOR XC 48 | AFNOR XC42 |
| DIN 1.1191 | JIS S 45C | JIS S 48 C | SS 1672 |
| ASTM A29 | ASTM A510 | ASTM A519 | ASTM A576 |
| FED QQ-S-635 (C1045) | FED QQ-S-700 (1045) | SAE J403 | ASTM A682 |
| SAE J414 | ASTM A183 (2-Nuts) | ASTM A236 (1045) | SAE J412 |
| ASTM A266 (1045) | ASTM A827 | ASTM A830 | QQ S700 (C1045) |
| SAE J1397 (1045) | | | |
Fabrication and Heat Treatment
Heat Treatment
AISI 1045 carbon steel can be heat treated using flame and induction hardening.
Forging
AISI 1045 carbon steel can be hammer forged.
Applications
The following are the application areas of AISI 1045 carbon steel:
- Bolts
- Studs
- Gears
- Axles
- Shafts
- Machine parts.
