8620 Steel vs 9310: What’s the Difference?
When it comes to selecting the right steel for your project, understanding the nuances between different alloys can be the…
In the world of engineering and manufacturing, choosing the right material is often the key to success. When it comes to steel, two popular options frequently surface: 8620 and 1018 steel. Each offers unique characteristics that can significantly impact the performance, durability, and efficiency of the final product. But what truly sets them apart? Understanding the differences between these two types of steel can be crucial, whether you’re an engineer trying to decide the best material for gears and shafts, a fabricator planning a complex welding job, or a manufacturer aiming to optimize your production line.
This article delves into the nuanced differences between 8620 and 1018 steel, exploring their chemical compositions, mechanical properties, and typical applications. We’ll guide you through the intricacies of welding these steels, including the selection of appropriate filler metals and necessary heat treatments. Additionally, we will compare their performance and durability under various conditions, providing a comprehensive analysis to help you make informed decisions. Whether you’re seeking to enhance your understanding of tensile strength and machinability or need practical advice for specific applications, this exploration of 8620 versus 1018 steel promises to illuminate the path to the most suitable choice for your needs.
Selecting the right steel grade is essential for ensuring durability and optimal performance in engineering applications. 8620 steel is a low-carbon alloy known for its excellent case hardening, making it ideal for components that need a tough, wear-resistant surface. On the other hand, 1018 steel is a mild, low-carbon steel valued for its combination of strength, ductility, and ease of machining. These two steels cater to different industrial needs, with their unique properties making them suitable for specific applications.
Choosing between 8620 and 1018 steel requires a clear understanding of their differences, as each offers unique benefits for specific uses. By understanding their chemical compositions and mechanical properties, manufacturers can select the best material for their needs, ensuring performance and durability. This helps align the chosen material with project requirements while improving manufacturing efficiency.
Selecting the appropriate type of steel is vital for ensuring the success of any engineering or manufacturing project. Two commonly used steels, 8620 and 1018, offer distinct properties tailored to different applications. This guide compares their chemical composition and mechanical properties to help you determine which steel best meets your needs.
The chemical composition of steel directly impacts its strength, hardness, machinability, and suitability for specific uses. Below is a breakdown of the key elements found in 8620 and 1018 steels.
The presence of alloying elements like nickel, chromium, and molybdenum enhances 8620 steel’s toughness and hardenability, making it well-suited for high-stress and wear-intensive applications.
1018 steel, classified as a plain carbon steel, lacks significant alloying elements. This makes it a cost-effective choice with excellent machinability, ideal for general-purpose applications.
A steel’s mechanical properties—such as tensile strength, yield strength, hardness, and machinability—determine its performance under stress and during fabrication.
Thanks to its alloying elements, 8620 steel offers superior strength and hardness, making it suitable for components subjected to high stress or requiring resistance to wear.
1018 steel excels in machinability and is a practical choice for projects where ease of fabrication and moderate strength are key priorities.
The fundamental differences between 8620 and 1018 steels lie in their chemical compositions and mechanical properties. While 8620 steel is tougher, stronger, and more resistant to wear, 1018 steel is more economical and easier to machine, making it versatile for general-purpose applications.
| Property | 8620 Steel | 1018 Steel |
|---|---|---|
| Carbon (C) | 0.18 – 0.23% | 0.15 – 0.20% |
| Chromium (Cr) | 0.4 – 0.6% | None |
| Manganese (Mn) | 0.7 – 0.9% | 0.6 – 0.9% |
| Nickel (Ni) | 0.4 – 0.7% | None |
| Molybdenum (Mo) | 0.15 – 0.25% | None |
| Tensile Strength | 640 MPa (92 ksi) | 430 MPa (62 ksi) |
| Yield Strength | 360 MPa (52 ksi) | 240 MPa (35 ksi) |
| Hardness | Rockwell B89, Brinell 183 | Brinell 126 |
| Machinability | 66% | Excellent |
This table provides a clear comparison of the two steels, allowing you to quickly identify which material is best suited for your project requirements.
8620 steel is a versatile alloy known for its excellent case hardening capabilities, providing a durable surface and a tough core, making it ideal for demanding industrial applications.
8620 steel is ideal for making gears and transmission parts due to its ability to withstand heavy wear and stress, ensuring reliability and longevity. This makes it a top choice for components that need to perform under rigorous conditions.
The strength and wear resistance of 8620 steel make it perfect for use in shafts, axles, bearings, and bushings. These components endure high stress and benefit from the steel’s ability to ensure long-lasting performance.
8620 steel is used for heavy-duty pins and bolts, providing the necessary strength and toughness to maintain structural integrity under high stress. This ensures that these components can handle demanding environments without failure.
The balance of strength and machinability in 8620 steel ensures the durability of hand tools and industrial equipment, even with frequent use. This makes it a reliable material choice for tools that require consistent performance over time.
1018 steel is a low-carbon steel known for its excellent machinability and moderate strength, making it versatile for general-purpose applications.
1018 steel is ideal for making general machinery parts like bushings and brackets, thanks to its machinability and ease of customization. This allows for the efficient production of various components used in everyday machinery.
In automotive applications, 1018 steel is used for components like hinges and brackets due to its moderate strength and cost-effectiveness. These properties make it a practical choice for automotive parts that require both durability and affordability.
1018 steel is a popular choice in construction for items like handrails and stair components because of its weldability and affordability. Its versatility makes it suitable for a variety of structural applications where reliable materials are essential.
From agricultural equipment to consumer goods like bicycle frames, 1018 steel’s ductility and affordability make it suitable for a wide range of applications. Its ability to be easily shaped and manufactured into various products highlights its versatility.
Welding 8620 steel requires careful preparation and attention to its unique properties to ensure strong and reliable results. As a low-carbon alloy steel, it is weldable using common techniques like gas and arc welding, but certain steps are essential for success.
Preheating for Durability
Before welding, preheat the steel to approximately 400°F (200°C). This step reduces temperature differences during the welding process, minimizing the risk of cracking. Proper preheating ensures a more uniform cooling rate and enhances the overall weld quality.
Post-Weld Heat Treatment (PWHT)
After welding, applying post-weld heat treatment is crucial to relieve residual stresses and improve toughness. This is particularly important for components subjected to dynamic loads, as it enhances their durability and performance.
Avoid Case-Hardened Welding
Welding on case-hardened 8620 steel is not recommended because it increases the likelihood of cracking. If welding is unavoidable, the hardened surface layer should be removed beforehand to reduce the risk.
In contrast, 1018 steel is highly weldable and straightforward to work with, thanks to its low carbon content. This steel accommodates various welding methods, making it a versatile choice for many applications.
Ease of Welding
1018 steel is compatible with a range of techniques, including gas and arc welding. Its low carbon content allows for smooth and consistent welds without the need for extensive preparation.
Heat Management
Preheating is generally unnecessary for 1018 steel unless working with sections thicker than 50 mm. In such cases, mild preheating can help prevent distortion. While post-weld heat treatment is not always required, it can enhance weld performance in applications demanding precision and strength.
Choosing the right filler metal is essential to ensure the weld is strong, compatible, and maintains the desired mechanical properties of the steel.
By understanding the distinct characteristics of 8620 and 1018 steels and following these guidelines, you can produce high-quality welds that are durable, reliable, and suited to the demands of the application. Whether working with alloy-rich materials like 8620 or the versatile 1018, proper preparation and technique make all the difference.
Selecting the appropriate steel for a specific application is critical to ensuring optimal performance, longevity, and cost-effectiveness. This comparison between 8620 and 1018 steel highlights their unique characteristics, helping you make an informed decision based on your needs.
One of the key differences between 8620 and 1018 steel lies in their toughness and hardness.
8620 Steel: The added elements, such as nickel and chromium, make 8620 steel exceptionally hard and resistant to wear. This combination allows it to withstand heavy loads and abrasive conditions. Its ability to be case-hardened provides a tough, durable surface while maintaining a softer, impact-resistant core. For example, this makes 8620 steel an excellent choice for manufacturing gears that must endure constant friction and stress.
1018 Steel: While not as hard as 8620, 1018 steel offers impressive ductility and flexibility. Its simpler composition, with lower carbon content, reduces the risk of cracking during processes like welding or forming. However, it lacks the natural wear resistance of 8620 and may require additional treatments for demanding applications. A common use for 1018 steel is in brackets or fixtures that require shaping and welding without compromising material integrity.
The composition of each steel type significantly influences its performance in high-stress environments.
8620 Steel: Thanks to its robust alloying elements, 8620 steel excels in high-stress conditions. It resists fatigue and wear, making it ideal for components like shafts or crankpins that operate under continuous load cycles and dynamic forces.
1018 Steel: This material is better suited for low to moderate stress applications. Its machinability and formability make it a practical choice for parts that don’t experience intense mechanical forces. For instance, 1018 steel might be used in low-load machine components or decorative hardware where heavy stress isn’t a factor.
The suitability of each steel type also depends on the service conditions and the expected lifespan of the component.
8620 Steel: Designed for challenging environments, 8620 steel maintains its structural integrity over time, even in applications involving wear and stress. Its durability makes it ideal for industries like automotive and heavy machinery, where components such as transmission gears must perform reliably over extended periods.
1018 Steel: Easier to shape, repair, and replace, 1018 steel is a cost-effective option for parts that require regular maintenance. For example, it is often used in applications like furniture frames or adjustable supports, where periodic adjustments or repairs are common.
Here’s a quick comparison to help you decide which material is best for your needs:
8620 Steel:
Excellent hardness and wear resistance due to alloying elements.
Ideal for high-stress applications like gears, shafts, and crankpins.
Provides a tough core with a hard, durable surface.
1018 Steel:
Highly ductile and easy to machine or weld.
Suitable for low to moderate stress applications, such as brackets and fixtures.
Easier to shape and maintain, ideal for components with regular upkeep needs.
By understanding the distinct qualities of 8620 and 1018 steel, you can ensure the material you select aligns with your project’s performance requirements and operational conditions.
Below are answers to some frequently asked questions:
SAE 8620 steel is a case-hardening alloy steel with a chemical composition that includes 96.895-98.02% iron (Fe), 0.700-0.900% manganese (Mn), 0.400-0.700% nickel (Ni), 0.400-0.600% chromium (Cr), 0.180-0.230% carbon (C), 0.150-0.350% silicon (Si), 0.150-0.250% molybdenum (Mo), and small amounts of sulfur (≤0.0400%) and phosphorus (≤0.0350%). This composition enhances the steel’s strength, toughness, and case-hardening properties.
SAE 1018 steel, on the other hand, is a low-carbon steel with a simpler composition. It primarily consists of iron with 0.150-0.200% carbon, 0.600-0.900% manganese, and smaller amounts of phosphorus (≤0.030%), sulfur (≤0.035%), and trace elements like chromium (≤0.150%), copper (≤0.200%), molybdenum (≤0.060%), and nickel (≤0.200%). The low carbon content makes SAE 1018 ductile and easy to form and weld.
The key differences between these steels are the presence of alloying elements like chromium, nickel, and molybdenum in SAE 8620, which contribute to its higher strength and hardness compared to the more ductile SAE 1018.
AISI 8620 steel generally has a higher tensile strength compared to AISI 1018 steel. In their untreated states, AISI 8620 exhibits an ultimate tensile strength of about 92 ksi, while AISI 1018 ranges from 63 to 70 ksi. With heat treatment, such as carburizing and hardening, AISI 8620 can achieve tensile strengths up to 115 ksi, significantly surpassing the capabilities of AISI 1018, which remains relatively stable in tensile strength without substantial heat treatment. This makes AISI 8620 more suitable for applications requiring higher strength and wear resistance, like gears and shafts.
For welding 8620 steel to 1018 steel, you should use a filler metal that matches the strength of the weaker material, which is 1018 steel. ER70S-3 is a suitable choice because it has a strength equivalent to that of 1018 steel. Additionally, ensure proper preheating to reduce the risk of cracking and consider post-weld heat treatment based on the specific service requirements to relieve residual stresses and achieve the desired mechanical properties.
When welding 8620 to 1018 steel, preheating is generally necessary, especially for 8620 steel, to slow the cooling rate, reduce hardness, and minimize the risk of cracking. Preheating may also be beneficial for 1018 steel, particularly for thicker sections or when welding to higher-carbon steels. Post-weld heat treatment (PWHT) is often preferred for 8620 steel to relieve residual stresses and improve mechanical properties, although it may not always be required for 1018 steel unless used in critical applications. The necessity of PWHT depends on service conditions, material thickness, and industry standards.
SAE-AISI 8620 steel is more suitable for making gears and shafts due to its superior mechanical properties, including higher tensile and yield strength, better fatigue and shear strength, and enhanced wear resistance through nitriding. These attributes ensure greater durability and performance under high-stress and high-wear conditions, which are critical for these applications. While 1018 steel offers excellent machinability, it lacks the strength and wear resistance required for gears and shafts, making 8620 the preferred choice.
