aisi 4130 alloy steel all introduction: properties, advantages, uses
aisi 4130 steel comprehensive introduction
What is Chromoly (4130 Steel)?
Chromoly (4130 steel) is a type of alloy steel that is commonly used in the manufacturing industry. It is known for its high tensile strength and weldability, making it an ideal material for various applications. The AISI 4130 steel is often found in the form of tubes or bars, commonly referred to as 4130 tubing or chromoly steel tubing. One of the main advantages of using 4130 tubing is its strong yet lightweight nature, making it a popular choice for structures that require both strength and weight savings. The mechanical properties of chromoly steel, such as its hardness and machinability, can be enhanced through the proper heat treatment processes, including annealing, normalizing, and tempering. The weldability of 4130 chromoly steel is excellent, and it is resistant to cracking and deformation during the welding process. In addition, 4130 steel tubing has a higher tensile strength compared to mild steel, making it a preferred choice where a thicker wall is needed.
Chemical Composition
The chemical composition of AISI 4130 alloy steel is listed in the following table.
Element | Content (%) |
Iron, Fe | 97.03 – 98.22 |
Chromium, Cr | 0.80 – 1.10 |
Manganese, Mn | 0.40 – 0.60 |
Carbon, C | 0.280 – 0.330 |
Silicon, Si | 0.15 – 0.30 |
Molybdenum, Mo | 0.15 – 0.25 |
Sulfur, S | 0.040 |
Phosphorous, P | 0.035 |
Physical Properties of 4130 Steel
4130 steel is a type of alloy steel that is often used in the machine and welding industries. It is known for its strong light weight steel tubing, making it an ideal choice for applications where both strength and weight are important factors. The weldability of 4130 chromolly steel tubing is excellent, allowing for easy and efficient fabrication of hollow structures. This type of steel also offers good resistance to scaling, making it suitable for use in high-temperature environments. Additionally, 4130 steel is capable of being hardened to various Rockwell hardness levels, providing flexibility in its applications. Its chromium, molybdenum, and carbon content give it equivalent strength as other types of steel with thicker walls, such as mild steel or L80. Whether used in seamless tubing or as a solid bar, 4130 steel is a versatile material that offers a combination of strength, durability, and machinability.
Density: The density of 4130 steel is typically around 7.85 g/cm³ (0.283 lb/in³), which is relatively moderate compared to other engineering alloys.
Melting Point: The melting point of 4130 steel falls within the range of approximately 1371°C to 1433°C (2500°F to 2611°F), depending on the specific composition and processing conditions.
Thermal Conductivity: 4130 steel exhibits a moderate thermal conductivity, typically ranging between 42 to 51 W/(m·K) at room temperature. This property determines its ability to conduct heat efficiently.
Specific Heat Capacity: The specific heat capacity of 4130 steel is approximately 0.475 J/g·K at room temperature, representing the amount of heat required to raise the temperature of a unit mass of the material by one degree Kelvin.
Coefficient of Thermal Expansion (CTE): The coefficient of thermal expansion of 4130 steel is around 11.7 µm/m·K (6.5 µin/in·°F) over the temperature range of 20°C to 100°C (68°F to 212°F). This property reflects the material’s tendency to expand or contract with changes in temperature.
Electrical Conductivity: 4130 steel is considered to be a poor conductor of electricity compared to materials like copper or aluminum. Its electrical conductivity is typically low, with values around 2.0 to 2.5% IACS (International Annealed Copper Standard).Magnetic
Properties: 4130 steel exhibits ferromagnetic behavior, meaning it can be magnetized in the presence of an external magnetic field.
However, the magnetic properties of 4130 steel can vary depending on factors such as composition, processing, and heat treatment.
Properties | Metric | Imperial |
Tensile strength, ultimate | 560 MPa | 81200 psi |
Tensile strength, yield | 460 MPa | 66700 psi |
Modulus of elasticity | 190-210 GPa | 27557-30458 ksi |
Bulk modulus (Typical for steel) | 140 GPa | 20300 ksi |
Shear modulus (Typical for steel) | 80 GPa | 11600 ksi |
Poissons ratio | 0.27-0.30 | 0.27-0.30 |
Elongation at break (in 50 mm) | 21.50% | 21.50% |
Reduction of area | 59.6 | 59.60% |
Hardness, Brinell | 217 | 217 |
Hardness, Knoop (Converted from Brinell hardness) | 240 | 240 |
Hardness, Rockwell B (Converted from Brinell hardness) | 95 | 95 |
Hardness, Rockwell C (Converted from Brinell hardness, value below normal HRC range, for comparison purposes only.) | 17 | 17 |
Hardness, Vickers (Converted from Brinell hardness) | 228 | 228 |
Machinability (Annealed and cold drawn. Based on 100% machinability for AISI 1212 steel.) | 70 | 70 |
Fabrication and Heat Treatment
4130 steel is ideal for fabrication and heat treatment processes due to its outstanding strength and low carbon content. The AISI 4130 alloy steel is commonly used in various industries such as aerospace, automotive, and oil and gas. The 4130 tube is resistant to scaling, making it suitable for applications where high temperatures are involved. This alloy steel is often chosen over mild steel where a thicker wall or higher strength is required, as it provides equivalent strength as the 4130 chromolly steel but with a lower weight. The 4130 steel alloy can be hardened through a quench and temper heat treatment process, resulting in a strong and durable material.
When it comes to fabrication, the 4130 tube is commonly forged to shape the desired components. It offers good strength and can withstand the rigors of the fabrication process. Heat treatment plays a crucial role in enhancing the properties of the alloy, including its hardness and toughness. The UNS G41300 grade 4130 steel is often used in the aerospace industry for its high strength-to-weight ratio and excellent weldability. The American Steel Institute recognizes it as a versatile material that can be easily machined and welded. Overall, the 4130 steel and its fabricated tube are highly favored in various applications due to their exceptional strength, resistance to scaling, and ease of fabrication.
Forming of AISI 4130 steel can be performed in the annealed condition.
- Welding of AISI 4130 steel can be performed by all commercial methods.
- Heat Treatment – AISI 4130 steel is heated at 871°C (1600°F) and then quenched in oil. This steel is usually heat-treated at temperatures ranging from 899 to 927°C (1650 to 1700°F).
- Forging of AISI 4130 steel can be performed at 954 to 1204°C (1750 to 2200°F).
- Hot working of AISI 4130 steel can be done at 816 to 1093°C (1500 to 2000°F).
- AISI 4130 steel can be cold worked using conventional methods.
- AISI 4130 steel can be annealed at 843°C (1550°F) followed by air cooling at 482°C (900°F).
- Tempering of AISI 4130 steel can be performed at 399 to 566°C (750 to 1050°F), depending on the desired strength level.
- Hardening of AISI 4130 steel can be done with cold working or heat treatment.
Machinability of Chromoly
Machinability of Chromoly:
The alloy 4130, commonly known as Chromoly, is a type of steel that is often used in place of mild steel due to its equivalent strength. The carbon steel inside of the tubing of Chromoly is hardened, which results in increased strength. This steel is forged and weldable, making it ideal for industries such as aviation and racing. It is one of the most widely used materials in these industries because of its weldability and ease of fabrication. Additionally, Chromoly is resistant to scaling and oxidation, making it ideal when a strong, light material is required. Its clean and smooth surface also contributes to its popularity. Overall, the machinability of Chromoly is highly favorable, making it a preferred choice in various applications within the aviation and racing industries.
What is 4130 steel equivalent to?
Other Designations
Other designations that are equivalent to AISI 4130 alloy steel include the following;
AMS 6348 | AMS 6371 | ASTM A331 | ASTM A829 | DIN 1.7218 |
AMS 6350 | AMS 6373 | ASTM A506 | MIL S-18729 | UNI 25 CrMo 4 |
AMS 6351 | AMS 6374 | ASTM A507 | MIL S-6758 | JIS SCCrM 1 |
AMS 6360 | AMS 6528 | ASTM A513 | SAE J1397 | JIS SCM 2 |
AMS 6361 | AMS 7496 | ASTM A519 | SAE J404 | SS 2225 |
AMS 6362 | ASTM A29 | ASTM A646 | SAE J412 | B.S. CDS 110 |
AMS 6370 | ASTM A322 | ASTM A752 | AFNOR 25 CD 4 (S) | SAE J770 |
About 4130 P+X steel:
4130 P+X steel is a high-strength steel that is widely used in aviation and racing. It is commonly used for structural applications in both industries because it offers an equivalent strength to the traditional mild steel while being hardened. This steel is known for its increased strength, which makes it ideal for applications where a thicker wall must be used. The 4130 P+X steel also has a clean and oxidation-free finish both on the outside and inside, making it a popular choice among motorcycle builders and race car chassis builders alike. Its equivalent strength and durability make it a preferred option in the industry. Whether it is for aviation or racing, the use of 4130 P+X steel ensures that the structural applications meet the required strength and performance standards.
About 4130 L80 Steel:
About 4130 L80 Steel:
4130 L80 steel is a high-strength alloy that offers equivalent strength as the 4130 mild steel. This type of steel is hardened and tempered, which increases its strength and makes it suitable for various applications. The addition of chromium and molybdenum as strengthening agents enhances the steel’s resistance to oxidation and ensures a clean finish. When using 4130 L80 steel, it is crucial to use the equivalent strength materials in order maintain the desired level of strength. Additionally, this steel exhibits good ductility, allowing for easy forming and shaping. The Society of Automotive Engineers acknowledges the quality and performance of 4130 L80 steel, making it a popular choice in the automotive industry. However, it is important to note that machining becomes difficult when the hardness of the steel is increased. Therefore, careful consideration and appropriate processes must be employed to ensure successful machining.
How is 4130 steel bar and tube made:
4130 steel bar and tube are made using a specific manufacturing process that involves several steps. Firstly, the mild steel is transformed into 4130 steel through a combination of alloy additions and heat treatment. This process enhances the material’s strength, allowing it to have an equivalent strength as the 4130. The high-strength properties of the 4130 steel bar and tube make them ideal for applications that require durability and reliability. Additionally, the material resists oxidation and has a clean surface, which ensures its longevity and performance. When manufacturing products that require the same level of strength as 4130 steel, it is crucial to use materials that have equivalent properties. This ensures that the final product will have the same level of strength and performance as if 4130 steel was used. Therefore, materials used in such applications must have equivalent the equivalent strength to meet the required standards.
Q: Is your 4130 tubing annealed or normalized?
we can do both heat traetment Yes, heat treatment can be done on 4130 steel. The two commonly employed heat treatment processes for 4130 steel are:
1. Annealing: This process involves heating the steel to a specific temperature, typically around 1600°F (870°C), and letting it cool slowly in a controlled manner. Annealing helps to relieve internal stresses and improve the machinability and formability of the steel.
2. Quenching and Tempering: This process involves heating the steel to a specific temperature (usually around 1550°F or 840°C) and then rapidly cooling it by immersing it in a quenching medium such as oil or water. This rapid cooling, known as quenching, hardens the steel, making it stronger but more brittle. To restore some toughness to the steel, it is then tempered by reheating it to a lower temperature (typically around 600°F or 315°C) and letting it cool slowly. This tempering process helps to reduce the brittleness and increase the ductility and toughness of the steel.
Both annealing and quenching and tempering heat treatments can be utilized to achieve desired properties in 4130 steel, depending on the specific application requirements.