The Define Of 45# Steel
45# steel, also known as Chinese GB standard 45 steel or 45Mn steel(China 45 steel = 45# steel = SAE 1045 steel), is a widely used carbon structural steel in China. Chinese GB standard 45 steel belongs to the group of high-quality carbon structural steels, which are commonly used in various machinery parts, components, and engineering structures. In this article, we will delve into the details of No. 45 steel, including its chemical composition, mechanical properties, heat treatment, applications, and more.(Related Service: Cnc Machining Steel 1045)
Data Sheet & Specification Of 45# Steel
Similar grades of 45# steel are S45C (JIS) and 1045 (AISI). In addition, there is SM45 grade in my country’s metallurgical technology standards that specifically indicates the use of plastic molds. Compared with 45# steel, SM45 has lower phosphorus and sulfur content and better steel purity.
| Steel Grade | 45# Steel |
|---|---|
| C | 0.42-0.50 |
| Si | 0.17-0.37 |
| Mn | 0.50-0.80 |
| P (≤) | 0.035 |
| S (≤) | 0.035 |
| Cr (≤) | 0.25 |
| Ni (≤) | 0.30 |
| Cu (≤) | 0.25 |
#45 Steel Mechanical Properties
The mechanical properties of #45 steel, also known as 45# steel or 45Mn steel, are essential factors to consider when evaluating its suitability for various applications. The following table provides typical mechanical properties for #45 steel:
| Mechanical Property | Value |
|---|---|
| Tensile Strength (MPa) | 600 – 700 |
| Yield Strength (MPa) | 355 |
| Elongation (%) | 16 – 20 |
| Reduction in Area (%) | 40 – 45 |
| Impact Toughness (J/cm²) | ≥ 39 |
It’s important to note that the mechanical properties of #45 steel can vary slightly depending on factors such as the specific manufacturing process, heat treatment, and the presence of any impurities or alloying elements. Therefore, it’s advisable to refer to the relevant material standards or data sheets for precise and detailed mechanical property information for a specific grade of #45 steel.
The Applications Of #45 Steel
#45 steel finds a wide range of applications across different industries due to its favorable properties. Some common applications of #45 steel include:
- Manufacturing Machinery Components: #45 steel is commonly used for manufacturing various machinery components such as gears, shafts, couplings, and connecting rods. Its combination of hardness, strength, and machinability makes it suitable for these applications.
- Structural Applications: Due to its moderate strength and toughness, #45 steel is utilized in structural applications. It is employed in the construction of buildings, bridges, and other engineering structures that require strength and durability.
- Automotive Industry: #45 steel is used in the automotive industry for manufacturing parts such as crankshafts, axles, and various mechanical components. Its properties, including hardness, toughness, and machinability, contribute to reliable and efficient performance in automotive applications.
- Tools and Cutting Equipment: The good hardness and machinability of #45 steel make it suitable for manufacturing tools and cutting equipment. It is commonly used for producing drills, taps, dies, and other cutting tools where wear resistance and toughness are essential.
- Agricultural Machinery: #45 steel is employed in the production of agricultural machinery components, including plows, harrows, and agricultural equipment parts. Its strength and durability allow it to withstand the demanding conditions of agricultural operations.
- General Manufacturing: Due to its versatility and favorable properties, #45 steel finds applications in general manufacturing processes. It is used in the production of various components, machine parts, and structural elements.
- It is widely used for general purpose applications where good machinability and moderate strength are required. It is often used in the production of bolts, screws, studs, and other similar parts.
The specific applications of #45 steel may vary depending on the requirements and specifications of different industries and manufacturers. Additionally, the appropriate heat treatment can further enhance the properties of #45 steel, making it suitable for specific applications.
Equivalent Grade
45# steel equivalent to US AISI SAE ASTM, European EN (Germany DIN EN, UK BS EN, France NF EN), Japanese JIS, and ISO standard.
| China | China | USA | USA | European | European | Japan | Japan | ISO | ISO |
|---|---|---|---|---|---|---|---|---|---|
| Standard | Grade | Standard | Grade | Standard | Steel name (Steel number) | Standard | Grade | Standard | Grade |
| GB/T 699 | 45 | AISI SAE, ASTM A29M | 1045 steel | EN 10083-2 | C45 (1.0503) | JIS G4051 | S45C | C45 |
The Diffenerce Of China 45 Steel and AISI SAE 1018 Steel
China 45 steel and AISI SAE 1018 steel are two distinct carbon steels with notable differences in their chemical compositions, mechanical properties, and applications. Here are the key differences between China 45 steel and AISI SAE 1018 steel:
1.Chemical Composition
China 45 Steel: It typically contains around 0.42-0.50% carbon, 0.17-0.37% silicon, 0.50-0.80% manganese, and trace amounts of phosphorus and sulfur.
AISI SAE 1018 Steel: It has a carbon content of approximately 0.15-0.20%, manganese content of 0.60-0.90%, and small amounts of other elements such as phosphorus and sulfur.
2.Manufacturing Standards:
China 45 Steel: It adheres to Chinese national standards, such as GB/T 699-2015.
AISI SAE 1018 Steel: It is standardized and recognized internationally through the AISI (American Iron and Steel Institute) and SAE (Society of Automotive Engineers) systems.
3.Mechanical Properties
China 45 Steel: It has a higher carbon content, leading to higher hardness and strength compared to AISI SAE 1018 steel. The typical tensile strength of China 45 steel is around 600-700 MPa, while its yield strength is approximately 355 MPa.
Here is a comparison table chart highlighting the key differences between China 45 steel and AISI SAE 1018 steel:
| Property | China 45 Steel | AISI SAE 1018 Steel |
|---|---|---|
| Chemical Composition | Carbon (C): 0.42-0.50% | Carbon (C): 0.15-0.20% |
| Chemical Composition | Silicon (Si): 0.17-0.37% | Manganese (Mn): 0.60-0.90% |
| Chemical Composition | Manganese (Mn): 0.50-0.80% | Phosphorus (P): ≤0.040% |
| Chemical Composition | Phosphorus (P): ≤0.035% | Sulfur (S): ≤0.050% |
| Chemical Composition | Sulfur (S): ≤0.035% | |
| Manufacturing Standards | GB/T 699-2015 | AISI/SAE J403 |
| Tensile Strength (MPa) | 600-700 | 440-580 |
| Yield Strength (MPa) | 355 | 280 |
| Elongation (%) | 16-20 | 15-20 |
| Reduction in Area (%) | 40-45 | 40-45 |
| Hardness (HB) | 137-170 | 121-149 |
| Machinability | Good | Excellent |
| Weldability | Fair | Excellent |
The specific chemical compositions and mechanical properties of these steels can vary slightly based on different manufacturing processes and standards. Therefore, it is recommended to consult the relevant material standards and data sheets for precise information when selecting the appropriate steel grade for a particular application.
The Heat Treatment Of China 45 Steel
The typical heat treatment process for China 45 steel involves the following steps:
- Normalizing: The first step is normalizing, which involves heating the steel to a temperature of around 850-880°C (1562-1616°F) and holding it at that temperature for a specific period. The duration depends on the steel’s thickness and size. The purpose of normalizing is to refine the steel’s microstructure and improve its overall mechanical properties.
- Annealing: After normalizing, the steel is annealed by heating it to a temperature of approximately 730-770°C (1346-1418°F) and holding it at that temperature for a specific duration. Annealing is performed to relieve internal stresses, soften the steel, and improve its machinability.
- Quenching: Quenching is a critical step that involves rapid cooling of the steel from a high temperature to room temperature or below. For China 45 steel, the recommended quenching medium is oil or water, depending on the desired hardness and mechanical properties. Quenching results in the formation of a hardened microstructure in the steel.
- Tempering: The final step in the heat treatment process is tempering. After quenching, the steel is reheated to a temperature range of approximately 550-570°C (1022-1058°F) and held at that temperature for a specific period. Tempering helps relieve internal stresses and enhances the steel’s toughness and ductility while reducing its brittleness.
The specific heat treatment parameters, such as heating temperatures, soaking times, and cooling rates, may vary depending on the specific requirements and applications of the steel. It is crucial to carefully control the heat treatment process to achieve the desired mechanical properties and performance for the intended application.
It’s important to note that the heat treatment process for China 45 steel should be performed by experienced professionals who have a thorough understanding of the steel’s properties and the heat treatment principles. Additionally, it is advisable to consult the relevant material standards or data sheets for precise and detailed heat treatment guidelines specific to China 45 steel.