Duplex and Super Duplex stainless steels are types of stainless steels that contain a mixture of both austenitic and ferritic microstructures. Duplex stainless steels typically have a 50/50 mixture of austenitic and ferritic microstructures, while super duplex stainless steels have a higher proportion of ferrite in the microstructure.

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The combination of the two microstructures in duplex and super duplex stainless steels results in a material that has improved strength and corrosion resistance compared to traditional austenitic or ferritic stainless steels. The high strength of duplex and super duplex stainless steels makes them suitable for use in structural and pressure-containing applications. The improved corrosion resistance also makes them suitable for use in environments where traditional stainless steels may not perform well, such as in marine and chemical processing applications.

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Duplex stainless steels are known for their excellent resistance to stress corrosion cracking, making them suitable for use in oil and gas exploration and production. Super duplex stainless steels have even better resistance to stress corrosion cracking, making them even more suitable for use in these applications.

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Duplex and super duplex stainless steels are also known for their excellent resistance to pitting and crevice corrosion, which makes them suitable for use in environments where these types of corrosion are a concern. They also have good resistance to chloride-induced stress corrosion cracking, which makes them suitable for use in environments where chloride ions are present.

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In conclusion, duplex and super duplex stainless steels are types of stainless steels that contain a mixture of both austenitic and ferritic microstructures. They have improved strength, corrosion resistance and excellent resistance to stress corrosion cracking, pitting and crevice corrosion, making them suitable for use in various industries such as marine, chemical processing, oil and gas exploration and production and other environments where traditional stainless steels may not perform well. Super duplex stainless steels have even better resistance to stress corrosion cracking than duplex stainless steels.