Dupleksiteräkset

Dupleksiteräkset, also known as duplex stainless steels, are a family of stainless steels that combine the advantages of ferritic and austenitic stainless steels. They possess a mixed microstructure, typically containing approximately 50% ferrite and 50% austenite. This unique microstructure provides a favorable balance of properties.

Key characteristics of duplex stainless steels include high strength, significantly greater than that of common austenitic grades like 304 or 316. They also exhibit good ductility and toughness, although typically not as high as fully austenitic steels. Duplex stainless steels offer excellent resistance to stress corrosion cracking, a phenomenon that can affect austenitic stainless steels in certain environments, particularly those containing chlorides. Their corrosion resistance is generally superior to 304 stainless steel and comparable to or better than 316 stainless steel in many environments.

The development of duplex stainless steels aimed to achieve improved mechanical properties and corrosion resistance while often offering a cost-effective solution compared to high-alloy austenitic or nickel-based alloys. Their applications span a wide range of industries, including oil and gas, chemical processing, pulp and paper, desalination plants, and structural components. Common grades include 2205 and the leaner duplex 2304. The properties of duplex stainless steels make them suitable for demanding environments where both strength and corrosion resistance are critical.

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