ThePipingMart Blog Grades Duplex Steel (UNS S32202) – Composition, Properties and Uses

Duplex Steel (UNS S32202) – Composition, Properties and Uses

Duplex Steel UNS S32202 -

Duplex steel UNS S32202 is one of the most versatile materials today. It is an alloy combining ferritic and austenitic stainless steel as its primary components. This combination gives it various mechanical, chemical, physical, and corrosion-resistant properties that make it ideal for industrial applications. This article will take a comprehensive look at the composition, properties, uses corrosion resistance, heat resistance, heat treatment, machining and welding aspects of duplex steel UNS S32202.

Duplex S32205 Chemical Composition

The composition of duplex steel UNS S32202 consists of 22% chromium (Cr), 4% nickel (Ni) and 3% molybdenum (Mo). The carbon content is shallow (0.03%), making it resistant to sensitization and ensuring high toughness even at shallow temperatures.

% C Mn P S Si Cr Ni Mo Cu N Fe
Min 21.5 1 0.18 balance
Max 0.03 2 0.04 0.01 1 24 2.8 0.45 0.26 balance

Duplex S32205 Chemical Properties

The nitrogen content is also higher than other stainless steels; this increases its strength without compromising ductility or formability. Additionally, it has excellent weldability due to its low carbon content.

Duplex S32205 Mechanical Properties

Duplex steel UNS S32202 has excellent mechanical properties, including high yield strength (YS) ranging from 0.2%-0.8%, ultimate tensile strength (UTS) ranging from 0.75%-1% and elongation ranging from 40%-60%. Its hardness is also very good; Brinell hardness ranges from 180-250, with typical values being 220-230 HBW, depending on the specific grade used in manufacturing. Furthermore, its toughness remains unchanged at cryogenic temperatures (-196°C).

20°C Tensile Strength Yield Strength Elongation % Hardness Density
Min 650Mpa 450Mpa 30% 7.8kg/dm3
Max 30HRC 7.8kg/dm3

Duplex S32205 Physical Properties

Its physical properties include a melting point of 1453°C – 1520°C and thermal conductivity of approximately 16 W/mK at 20°C – 100°C. Its density is 8g/cm3, and its specific gravity is 7.9 g/cm3. Additionally, its electrical resistivity ranges from 46 μΩ cm to 61 μΩ cm at 20°C – 100°C respectively, which makes it suitable for various applications requiring electrical insulation such as power cables etc.

Corrosion Resistance

Duplex Steel UNS S32202 has excellent corrosion resistance in acidic and chloride-rich environments such as seacoasts or ocean water contact areas.


It can be used in oil & gas production, petrochemical plants, desalination plants, offshore platforms, chemical processing plants etc. Additionally, its high chromium content makes it highly resistant to pitting when exposed to chlorides which makes this material ideal for components operating in highly corrosive environments such as seawater pumps etc.

Heat Treatment

Cold-working methods and heat treatment can harden Duplex Steel UNS S32202; however, cold working produces better results mainly because of the improved ductility achieved by this method.

Heat Resistance

Its maximum temperature limit is 800 °F but should not be exceeded if maximum hardness needs to be maintained; if higher temperatures are required, then different grades with higher heat resistance should be used instead.


Duplex Steel UNS S32202 can easily be machined using conventional tools such as drills, taps etc. However, care must be taken when machining because cutting speeds should not exceed 2000 fpm; otherwise, premature tool wear may result in poorer surface finish or increased vibration during machining operations.


Additionally, this material can also be used successfully with welding processes like MIG welding or TIG welding. However, due to its high carbon content, one must ensure proper preheat temperature before starting any welding operation; otherwise, cracking may occur while the cooling down process after welding.


In conclusion, duplex steel UNS S32202 offers outstanding performance for a wide range of industrial applications thanks to its excellent combination of mechanical properties such as high yield strength, ultimate tensile strength, hardness along with superior corrosion resistance in various environments such as acidic ones or those containing chlorides like seawater contact areas etc. Furthermore, it has good weldability due to low carbon content and easy machinability using standard tools; additionally, appropriate heat treatments can also improve the overall performance characteristics significantly, making it an ideal choice for many industrial requirements across multiple industries worldwide!

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