Our Tools' Material AISI 1045,AISI5140
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- Issue Time
- Jul 8,2015
AISI 1045 Medium Carbon Steel
Introduction
AISI 1045 steel is a medium tensile steel supplied in the black hot rolled or normalized condition. It has a tensile strength of 570 - 700 MPa and Brinell hardness ranging between 170 and 210.
AISI 1045 steel is characterized by good weldability, good machinability, and high strength and impact properties in either the normalized or hot rolled condition.
AISI 1045 steel has a low through-hardening capability with only sections of size around 60 mm being recommended as suitable for tempering and through-hardening. However, it can be efficiently flame or induction hardened in the normalized or hot rolled condition to obtain surface hardnesses in the range of Rc 54 - Rc 60 based on factors such as section size, type of set up, quenching medium used etc.
AISI 1045 steel lacks suitable alloying elements and hence does not respond to the nitriding process.
Chemical Composition
| Element | Content |
|---|---|
| Carbon, C | 0.420 - 0.50 % |
| Iron, Fe | 98.51 - 98.98 % |
| Manganese, Mn | 0.60 - 0.90 % |
| Phosphorous, P | ≤ 0.040 % |
| Sulfur, S | ≤ 0.050 % |
Physical Properties
| Physical Properties | Metric | Imperial |
|---|---|---|
| Density | 7.87 g/cc | 0.284 lb/in3 |
Mechanical Properties
| Mechanical Properties | Metric | Imperial |
|---|---|---|
| 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 |
| Tensile Strength, Ultimate | 565 MPa | 81900 psi |
| Tensile Strength, Yield | 310 MPa | 45000 psi |
| Elongation at Break (in 50 mm) | 16.0 % | 16.0 % |
| Reduction of Area | 40.0 % | 40.0 % |
| Modulus of Elasticity (Typical for steel) | 200 GPa | 29000 ksi |
| Bulk Modulus (Typical for steel) | 140 GPa | 20300 ksi |
| Poissons Ratio (Typical For Steel) | 0.290 | 0.290 |
| Shear Modulus (Typical for steel) | 80 GPa | 11600 ksi |
Machining
AISI 1045 steel has good machinability in normalized as well as the hot rolled condition. Based on the recommendations given by the machine manufacturers, operations like tapping, milling, broaching, drilling, turning and sawing etc. can be carried out on AISI 1045 steel using suitable feeds, tool type and speeds.
Welding
Certain facts about welding of AISI 1045 steel are:
- AISI 1045 steel is readily welded when correct procedure is followed.
- Welding AISI 1045 steel in through-hardened, tempered and flame or induction hardened condition is not recommended.
- Low hydrogen electrodes are preferred for welding AISI 1045 steel.
- The workpiece is
- Pre-heated at 200°C–300°C (392°F - 572°F)
- Maintained at the same temperature during welding
- Cooled slowly using sand, ashes etc and
- Stress relieved at 550°C - 660°C (1022°F - 1220°F).
Heat Treatment
AISI 1045 is subjected to the following processes:
- Forging
- Annealing
- Normalizing
- Stress relieving
- Hardening
- Tempering
Forging
- Heat to 850°C - 1250°C (1562°F - 2282°F)
- Hold until the temperature is uniform
- Cool in furnace
Annealing
- Heat to 800°C - 850°C (1472°F - 1562°F)
- Hold until the temperature is uniform
- Cool in furnace.
Normalizing
- Heat to 870°C - 920°C (1598°F-1688°F)
- Hold until the temperature is uniform
- Soak for 10 - 15 minutes
- Cool in still air
Stress Relieving
- Heat to 550°C - 660°C (1022°F - 1220°F)
- Hold until the temperature is uniform
- Soak for 1 hour per 25mm of section
- Cool in still air
Hardening
- Heat to 820°C - 850°C (1508°F - 1562°F)
- Hold until the temperature is uniform
- Soak for 10 - 15 minutes per 25mm of section
- Quench in water or brine
Tempering
- Re-heat to 400°C - 650°C (752°F - 1202°F ) as required
- Hold until the temperature is uniform
- Soak for 1 hour per 25mm of section
- Cool in still air
Applications
AISI 1045 is widely used for all industrial applications requiring more wear resistance and strength. Typical applications of AISI 1045 are as follows:
| Gears | Pins | Rams |
| Shafts | Rolls | Sockets |
| Axles | Spindles | Worms |
| Bolts | Ratchets | Light gears |
| Studs | Crankshafts | Guide rods |
| Connecting rods | Torsion bars | Hydraulic clamps |
AISI 5140 Alloy Steel
Introduction
Alloy steels comprise a wide range of steels whose compositions are more than the limitations of C, Mo, Cr, Va, Mn, Ni, Si, and B which have been fixed for carbon steels. These steels are more responsive to mechanical and heat treatments than carbon steels.
The following datasheet will provide details about AISI 5140 alloy steel.
Chemical Composition
The following table shows the chemical composition of AISI 5140 alloy steel.
| Element | Content (%) |
|---|---|
| Iron, Fe | 97.395-98.07 |
| Manganese, Mn | 0.700-0.900 |
| Chromium, Cr | 0.700-0.900 |
| Carbon, C | 0.380-0.430 |
| Silicon, Si | 0.150-0.300 |
| Sulfur, S | ≤ 0.0400 |
| Phosphorous, P | ≤ 0.0350 |
Physical Properties
The physical properties of AISI 5140 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 5140 alloy steel are highlighted in the table below.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 570 MPa | 82700 psi |
| Yield strength | 295 MPa | 42800 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 | 41.0 J | 30.2 ft.lb |
| Hardness, Brinell | 167 | 167 |
| Hardness, Knoop (converted from Brinell hardness) | 188 | 188 |
| Hardness, Rockwell B (converted from Brinell hardness) | 85 | 85 |
| Hardness, Vickers (converted from Brinell hardness) | 175 | 175 |
| Machinability (annealed and cold drawn, based on 100 machinability for AISI 1212 steel) | 65 | 65 |
Thermal Properties
The thermal properties of AISI 5140 alloy steel are provided in the table below.
| Properties | Metric | Imperial |
|---|---|---|
| Thermal conductivity | 44.6 W/mK | 310 BTU in/hr.ft².°F |
| Thermal expansion co-efficient (@20-200°C/68-392°F) | 12.6 µm/m°C | 7 µin/in°F |
Other Designations
Equivalent materials to AISI 5140 alloy steel are as follows.
| AFNOR 42 C 2 | AFNOR 42 C 4 | DIN 1.7035 | UNI 40 Cr 4 | UNI 41 Cr 4 KB | JIS SCr 4 H |
| B.S. 2 S 117 | B.S. 530 A 40 | B.S. 530 H 40 | B.S. 530 M 40 | ASTM A322 | ASTM A331 |
| ASTM A505 | ASTM A519 | SAE J404 | SAE J412 | SAE J770 |