The Different Stainless Steel Grades | Intamet

22 May 2024

At Intamet, we are proud to offer a wide range of stainless steel grades to meet the diverse needs of our clients. Each grade has unique properties that make it suitable for specific applications. This blog will explore the different stainless steel grades, their characteristics, and their uses.

Understanding Stainless Steel Grades

Stainless steel grades are classified based on their composition and properties. The primary categories include austenitic, ferritic, martensitic, and duplex steels. Each category offers specific advantages, making certain grades more suitable for particular applications.

Key Stainless Steel Grades

Austenitic Stainless Steel

Grades: 304, 316, 321
Properties: Non-magnetic, excellent formability, and corrosion resistance.
Uses: Kitchenware, chemical processing equipment, architectural structures.
Benefits: Austenitic stainless steels are versatile and widely used due to their excellent corrosion resistance and ease of fabrication.

Ferritic Stainless Steel

Grades: 430, 409
Properties: Magnetic, good resistance to stress corrosion cracking.
Uses: Automotive exhaust systems, industrial machinery.
Benefits: Ferritic stainless steels are known for their good mechanical properties and cost-effectiveness.

Martensitic Stainless Steel

Grades: 410, 420, 440C
Properties: High strength, hardness, and wear resistance.
Uses: Cutting tools, surgical instruments, and valves.
Benefits: Martensitic stainless steels are ideal for applications requiring high strength and wear resistance.

Duplex Stainless Steel

Grades: 2205, 2507
Properties: Combines the properties of austenitic and ferritic steels, offering high strength and excellent corrosion resistance.
Uses: Chemical processing, marine environments, oil and gas industry.
Benefits: Duplex steels provide a balance of strength and corrosion resistance, making them suitable for harsh environments.

Super Duplex Stainless Steel

Grades: 32750, 32760
Properties: Higher chromium and molybdenum content, offering superior strength and resistance to corrosion.
Uses: Offshore platforms, desalination plants.
Benefits: Super duplex steels are designed for extreme conditions, providing excellent performance in demanding applications.

Common Applications of Stainless Steel Grades

Construction and Architecture

Applications: Structural components, facades, handrails.
Benefits: Stainless steel grades such as 304 and 316 are used for their durability and aesthetic appeal. They withstand environmental exposure and maintain their appearance over time.

Petrochemical and Marine Industries

Applications: Pipelines, storage tanks, marine structures.
Benefits: Grades like 316 and duplex steels resist harsh chemicals and saltwater environments, ensuring long-term performance.

Food and Beverage Industry

Applications: Processing equipment, storage tanks, kitchenware.
Benefits: Grades like 304 and 316 are favoured for their hygienic properties and corrosion resistance, making them ideal for food contact surfaces.

Automotive and Aerospace

Applications: Exhaust systems, structural components, trim.
Benefits: Grades like 409 and 321 offer the necessary strength, corrosion resistance, and temperature tolerance required in these sectors.

Medical Field

Applications: Surgical instruments, medical devices, implants.
Benefits: Grades like 316L and 420 are used for their biocompatibility, resistance to sterilisation processes, and strength.

FAQs About Stainless Steel Grades

Q: What are the main categories of stainless steel grades?

A: The main categories include austenitic, ferritic, martensitic, and duplex stainless steels, each with unique properties.

Q: How do I choose the right stainless steel grade for my application?

A: Consider corrosion resistance, strength, formability, and the environment where you will use the steel. Consulting with experts can help you select the best grade.

Q: What is the difference between 304 and 316 stainless steel?

A: 304 stainless steel, an austenitic grade, excels in corrosion resistance and formability. 316 stainless steel contains molybdenum, which enhances its resistance to chlorides and acids, making it suitable for more corrosive environments.

Q: Can stainless steel grades be welded?

A: Yes, most stainless steel grades can be welded. However, the welding technique and filler material may vary depending on the grade.

Q: What is duplex stainless steel used for?

A: Duplex stainless steel excels in applications requiring high strength and excellent corrosion resistance, such as chemical processing, marine environments, and the oil and gas industry.

Q: How does the chromium content affect stainless steel properties?

A: Higher chromium content enhances corrosion resistance by forming a protective oxide layer on the steel’s surface, preventing rust and degradation.

Q: Are there specific grades for high-temperature applications?

A: Yes, grades like 310S and 321 excel in high-temperature applications, providing excellent oxidation resistance and strength at elevated temperatures.

Q: What are super duplex stainless steels?

A: Super duplex stainless steels have higher chromium and molybdenum content, providing superior strength and resistance to corrosion, particularly in extreme environments.

Q: How do I maintain stainless steel to prevent corrosion?

A: Regular cleaning with mild detergents and avoiding exposure to harsh chemicals can help maintain the protective oxide layer and prevent corrosion.

Q: What makes martensitic stainless steel suitable for cutting tools?

A: Martensitic stainless steels offer high strength, hardness, and wear resistance, making them ideal for applications like cutting tools and surgical instruments.

Contact Us

For more information or to discuss your stainless steel requirements, please visit our Contact Page, email us at sales@intamet.co.uk, or call us at +44 1329 84 3355.