When choosing stainless steel for industrial applications, UNS S31803 Pipes and Super Duplex Steel S32760 Seamless Tubes are among the top choices. Such super duplex stainless steels are characterized by high strength, excellent corrosion and erosion resistance, as well as high durability. However, they have key differences that make them suitable for specific applications.
Chemical Composition
One of the main differences between UNS S31803 and Super Duplex Steel S32760 is their chemical composition.
UNS S31803 contains approximately 22% chromium, 5% nickel and 3% molybdenum. This composition gives pipes good resistance to pitting and crevice corrosion.
Super Duplex Steel S32760 has a higher content of chromium (24-26%), nickel (6-8%) and molybdenum (3-5%). They also contain tungsten and copper which enhance corrosion resistance in harsh environments.
Strength and Mechanical Properties
Both materials offer excellent strength, but Super Duplex Steel S32760 Seamless Tubes are slightly stronger.
UNS S31803 have a tensile strength of around 620 MPa and yield strength of 450 MPa.
Super Duplex Steel S32760 possess a tensile strength of 750 MPa and yield strength of 550 MPa and thus they are suited for high pressure applications.
Corrosion Resistance
Both alloys offer excellent corrosion resistance, but Super Duplex Steel S32760 Seamless Tubes perform better in aggressive environments.
UNS S31803 Pipes are resistant to general corrosion, pitting and stress corrosion cracking.
Super Duplex Steel S32760 Seamless Tubes have high resistance to seawater, acidic conditions and chloride environments hence used for offshore and marine applications.
Applications
Whether to use UNS S31803 Pipes or Super Duplex Steel S32760 Seamless Tubes depends on the specific need of an application.
UNS S31803 Pipes are used in chemical processing, oil and gas and water treatment industries.
Super Duplex Steel S32760 Seamless Tubes are used in offshore platforms, desalination plants and other industries where high corrosion resistance is required.
Cost Consideration
Super Duplex Steel S32760 Seamless Tubes cost more as compared to UNS S31803 Pipes because of the higher content of alloy in the material. But their long-term stability and resistance to severe conditions make them an economical solution for challenging environments.
Conclusion
Both UNS S31803 and Super Duplex Steel S32760 offer high strength and corrosion resistance. But if your application demands more strength and durability in addition to the best resistance against harsh conditions, then you should go for Super Duplex Steel S32760 Seamless Tubes. UNS S31803 Pipes are cost-effective and thus can be used in various industrial applications where superior performance is not crucial.
