1. Perkenalan
Stainless steel is a versatile and durable material, it is widely used across various industries for its excellent corrosion resistance, kekuatan, dan daya tarik estetika.
Two commonly used casting stainless steel grades are CF3 (Type 304L) and CF8 (Type 304).
Understanding these grades’ key differences, properties, and applications is crucial for selecting the right material for specific needs.
This blog post aims to comprehensively compare CF3 and CF8, helping engineers, designers, and manufacturers make informed decisions.
2. What is CF3 Stainless Steel?
Definition and Composition
CF3 is the cast equivalent of 304L stainless steel, characterized by its low carbon content (typically less than 0.03%).
This lower carbon content helps prevent carbide precipitation during welding, which can lead to intergranular corrosion.
Its composition consists of approximately 18-21% kromium, 8-11% nikel, and small additions of Molybdenum, which enhances its corrosion resistance.
Similar Specifications
- Cast UNS: J92500.
- Wrought UNS: S30403.
- Wrought Grade: 304L.
- Cast Grade: CF3.
- Cast ASTM: A351, A743, A744.
- Military/AMS: AMS 5371.
Advantages of CF3
- Enhanced weldability: The low carbon content of CF3 makes it more suitable for welded applications, as it reduces the risk of carbide formation, which can compromise the steel’s integrity.
- Reduced risk of sensitization: CF3 minimizes the likelihood of sensitization, making it an ideal choice for applications involving high heat and welded components.
- Corrosion resistance: CF3 offers excellent resistance to corrosive chemicals Dan chloride pitting, making it a good option for industries such as food processing and pharmaceuticals.
3. What is CF8 Stainless Steel?
Definition and Composition
CF8 is the cast counterpart of 304 baja tahan karat and has a higher carbon content (up to 0.08%) than CF3.
This increased carbon content gives CF8 higher mechanical strength and hardness, while still maintaining good corrosion resistance.
CF8 is made up of 18-21% kromium, 8-11% nikel, and trace amounts of Molybdenum.
Similar Specifications
- Cast UNS: J92600
- Wrought UNS: S30400
- Wrought Grade: 304
- Cast Grade: CF8
- Cast ASTM: A351, A743, A744
Advantages of CF8
- Higher strength and hardness: Thanks to its higher carbon content, CF8 offers better mechanical properties, making it ideal for applications where strength and wear resistance are crucial.
- Good corrosion resistance: CF8 maintains solid general-purpose corrosion resistance, although it may not perform as well as CF3 in highly corrosive environments.
4. Properties of CF3 vs. CF8 Stainless Steel
Sifat mekanik
- Kekuatan tarik: CF8 generally has a higher tensile strength, typically around 485 MPa compared to CF3, which averages around 450 MPa.
- Kekuatan luluh: CF8 also has a higher yield strength, around 215 MPa, compared to CF3’s 170 MPa.
- Kekerasan: CF8’s higher carbon content results in greater hardness, making it more resistant to wear and mechanical deformation.
- Pemanjangan: CF3 offers better elongation properties, around 35-40%, giving it more ductility and flexibility, particularly beneficial for forming and welding operations.
Physical Properties
- Kepadatan: Both CF3 and CF8 have a density of 7.8 g/cm³, making them lightweight yet durable.
- Konduktivitas termal: CF3 has slightly better thermal conductivity, pada 16.2 W/m·K, compared to CF8’s 14.8 W/m·K. This makes CF3 more effective in heat-exchanging applications.
- Ekspansi termal: Both grades exhibit similar thermal expansion rates, around 17.2 μm/m·K, but CF3’s low carbon content can provide better dimensional stability in heat cycles.
Resistensi korosi
- General Resistance: CF3 outperforms CF8 in environments prone to chloride pitting Dan stress corrosion cracking, due to its low carbon content.
CF8, while still resistant to corrosion, may not perform as well under extreme chemical exposure. - Chloride and Acid Resistance: CF3 has superior resistance to chloride-induced corrosion and is more effective in applications exposed to harsh acids, such as in chemical processing plants.
Temperature Resistance
- Kinerja suhu tinggi: CF8 can withstand higher operating temperatures, up to 870° C. (1600° f), making it more suitable for high-heat environments.
CF3, while also heat resistant, may not perform as well under continuous high-temperature stress. - Scaling and Oxidation: CF8 offers better resistance to scaling at elevated temperatures, which is an advantage for industrial applications such as furnaces or exhaust systems.
Weldability and Formability
- Kemampuan las: CF3 has superior weldability due to its lower carbon content. It is less prone to sensitization, making it ideal for welded structures that cannot undergo post-weld heat treatment.
CF8, on the other hand, may require more care during welding to avoid issues like cracking or warping. - Formability: Both materials are relatively easy to form, but CF3’s lower carbon content makes it more malleable and better suited for applications requiring complex shapes or heavy-gauge components.
5. Benefits of Using CF3 vs. CF8 Stainless Steel in Castings
CF3 Benefits
- Superior Weldability: Enhanced weldability with a lower risk of intergranular corrosion, making it ideal for heavy-gauge welded components.
In a study, CF3 showed a 30% reduction in the incidence of weld-related defects compared to CF8. - Low Risk of Sensitization: The low carbon content reduces the risk of sensitization, ensuring consistent corrosion resistance.
This makes CF3 particularly suitable for critical applications where corrosion resistance is paramount. - Cost-Effectiveness for Heavy-Gauge Welded Components: CF3 is often more cost-effective for large, thick-walled components that require extensive welding.
Misalnya, in a project involving the construction of a large chemical reactor, using CF3 resulted in a 20% reduction in overall costs due to fewer rework and maintenance issues.
CF8 Benefits
- High Strength and Durability: CF8 offers higher tensile and yield strengths, making it suitable for applications requiring greater structural integrity.
In a test, CF8 demonstrated a 10% higher tensile strength compared to CF3 under similar conditions. - Excellent General-Purpose Corrosion Resistance: CF8 provides reliable performance in a wide range of corrosive environments.
In a marine environment, CF8 showed a 15% lower rate of corrosion compared to other common stainless steels. - Versatility in a Wide Range of Applications: CF8’s balanced properties make it a versatile choice for various industrial and commercial applications.
It is commonly used in applications ranging from food processing to automotive components.
6. Applications of CF3 vs. CF8 Stainless Steel
CF3 Stainless Steel Applications
- Chemical Processing Equipment: Reactors, tanks, and pipelines in chemical plants. CF3 is often chosen for its superior resistance to aggressive chemicals.
- Food and Beverage Industry: Equipment and machinery for food processing and storage. CF3’s low carbon content ensures minimal contamination and easy cleaning.
- Pharmaceutical Industry: Sterilization equipment, process vessels, and pharmaceutical-grade components.
The enhanced corrosion resistance of CF3 is critical in maintaining sterile conditions. - Architectural and Decorative Elements: Structural and decorative elements in buildings and public spaces.
CF3’s aesthetic appeal and durability make it a popular choice for architectural projects.
CF8 Stainless Steel Applications
- Marine Hardware: Shipbuilding, offshore platforms, and marine hardware. CF8’s high strength and corrosion resistance make it ideal for harsh marine environments.
- Industrial Machinery: Pompa, katup, and other critical components in industrial settings.
CF8’s robust mechanical properties ensure reliable performance in demanding industrial applications. - Pumps and Valves: Components in fluid handling systems. CF8’s resistance to corrosion and wear makes it a preferred choice for pumps and valves.
- Automotive Components: Exhaust systems, engine parts, and other automotive components. CF8’s high strength and durability are essential for automotive applications.
- Alat kesehatan: Instrumen Bedah, Implan medis, and diagnostic equipment. CF8’s biocompatibility and corrosion resistance make it suitable for medical devices.
7. CF3 vs. CF8 Stainless Steel.: When to Choose Which Grade
Comparison summary
- Table of Key Differences:
| Milik | CF3 (Type 304L) | CF8 (Type 304) |
|---|---|---|
| Carbon Content | ≤0.03% | ≤0.08% |
| Kekuatan tarik | 70,000 psi (482 MPa) | 75,000 psi (517 MPa) |
| Kekuatan luluh | 30,000 psi (207 MPa) | 30,000 psi (207 MPa) |
| Kekerasan | 187 HB (Brinell Hardness) | 187 HB (Brinell Hardness) |
| Pemanjangan | ≥40% in 2 inches (50 mm) | ≥40% in 2 inches (50 mm) |
| Kepadatan | 0.29 lb/in³ (8.0 g/cm³) | 0.29 lb/in³ (8.0 g/cm³) |
| Konduktivitas termal | 9.2 Btu/(hr·ft·°F) (16.3 W/m·K) | 9.2 Btu/(hr·ft·°F) (16.3 W/m·K) |
| Electrical Conductivity | 1.3 × 10^6 S/m | 1.3 × 10^6 S/m |
| Thermal Expansion Coefficient | 9.4 × 10^-6/°F (17.0 × 10^-6/°C) | 9.4 × 10^-6/°F (17.0 × 10^-6/°C) |
| Resistensi korosi | Superior, especially in highly corrosive environments | Good general-purpose corrosion resistance |
| Risk of Intergranular Corrosion | Rendah | Sedang |
| Kemampuan las | Superior, lower risk of sensitization | Bagus, but higher risk of sensitization |
| Cost-Effectiveness | Higher for heavy-gauge welded components | Balanced for general use |
When to Choose CF3
- Welded Components Requiring Low Risk of Sensitization: CF3 is ideal for heavy-gauge welded components where the risk of intergranular corrosion must be minimized.
Misalnya, in the construction of large storage tanks, CF3’s superior weldability and low risk of sensitization make it the preferred choice. - Heavy-Gauge Parts: CF3 is more cost-effective and reliable for large, thick-walled components.
In a recent project, using CF3 for a 10-foot diameter pipeline reduced the overall cost by 15% compared to using CF8. - Applications in Highly Corrosive Environments: CF3’s enhanced corrosion resistance makes it suitable for environments with high levels of chlorides and other corrosive agents.
In a chemical plant, CF3 was chosen for a reactor exposed to highly acidic solutions, resulting in a 25% reduction in maintenance costs over five years.
When to Choose CF8
- General-Purpose Applications: CF8 is a versatile choice for a wide range of applications, offering a balance of strength and corrosion resistance.
Misalnya, in the food and beverage industry, CF8 is commonly used for processing equipment and storage tanks. - Components Requiring Higher Strength and Hardness: CF8 is preferred for applications that demand greater structural integrity.
In an automotive application, CF8 was selected for exhaust system components due to its high strength and durability. - Environments with Moderate Corrosion Risk: CF8 provides reliable performance in moderately corrosive environments, making it a cost-effective choice for many industrial and commercial applications.
In a marine setting, CF8 was used for shipbuilding and offshore platforms, demonstrating excellent resistance to saltwater corrosion.
8. Kesimpulan
Both CF3 Dan CF8 baja tahan karat have their unique strengths, and the choice between the two depends on the specific requirements of the application.
CF3 is preferred in situations where corrosion resistance, kemampuan las, and ductility are paramount, while CF8 offers enhanced strength and general-purpose corrosion resistance.
By understanding the differences between CF3 and CF8, manufacturers and engineers can make more informed decisions, ensuring the longevity and reliability of their stainless steel castings.
9. How to Purchase Stainless Steel Castings from DEZE？
To ensure efficient processing and production, we recommend providing detailed drawings of the required castings.
Our team works primarily with software such as SolidWorks and AutoCAD, and we can accept files in the following formats: IGS, STEP, as well as CAD and PDF drawings for further evaluation.
If you do not have ready-made drawings or designs, simply send us clear pictures with the main dimensions and the unit weight of the product.
Our team will assist you in creating the necessary design files using our software.
Alternatively, you can send us a physical sample of the product. We offer 3D scanning services to generate accurate designs from these samples.
This service is offered free of charge, and we’re happy to support you throughout the process to ensure the best results.
DEZE has been engaged in the foundry industry for more than 20 years. If you have any stainless steel processing needs, Mohon jangan ragu Hubungi kami.
