Duplex Steel 2205 / UNS S32205 Forged-Fittings

The 2205 alloy is the top choice among Duplex stainless steels, making up over 80% of the market. It provides excellent corrosion resistance under various conditions compared to 316L and offers higher yield strength. Every 2205 alloy undergoes metallographic testing to ensure it’s free from harmful phases like sigma. These alloys are widely used in welded pipes, tubular components, and applications needing resistance to general corrosion and chloride stress corrosion cracking.

DUPLEX STEEL 2205 / S32205 SOCKET WELD FITTINGS SPECIFICATIONS

S32205 DUPLEX FORGED-FITTING CHEMICAL COMPOSITION

SPECIFICATION EQUIVALENTS :

UNS S31803, UNS S32205, EN 1.4462

ASTM A182, A240, A276, A789, A790 and A 815

DUPLEX STEEL S31803 / S32205 FORGED-FITTING MECHANICAL PROPERTIES

PHYSICAL PROPERTIES :

General Characteristics:  

PREN value is 34 (Pitting Resistance Equivalent Number: %Cr + 3.3 × %Mo + 16 × %N).  

This is an extra-low-carbon duplex stainless steel with a yield strength nearly double that of austenitic stainless steels. It has excellent weldability and minimal inter-granular corrosion in a welded state. It offers high resistance to stress corrosion cracking (SCC) in chloride and hydrogen sulfide environments. Additionally, it demonstrates exceptional resistance to corrosion fatigue, pitting, crevice corrosion, and erosion-corrosion.  

Machinability:  Machining with high-speed steel tools follows the same procedures as for AISI 316. For carbide-tipped tools, cutting speeds should be reduced by 40% for roughing and 20% for finishing compared to AISI 316.  

Fabricability:  The force required for plastic deformation is nearly twice that needed for AISI 304L and 316L. Beyond the yield strength, plastic deformation proceeds as smoothly as in austenitic stainless steel. It can be cold bent up to 25% deformation without requiring heat treatment, though annealing is recommended if SCC-prone conditions exist. Hot bending should occur between 950–1100°C, followed by quench annealing. Tube expansion can be achieved using normal methods, but it requires a higher initial force and should be done in a single operation.  

Weldability:  It is easily welded using Manual Metal Arc Welding (MMAW) with a covered electrode, Gas Tungsten Arc Welding (GTAW), or Gas Metal Arc Welding (GMAW). Heat input should range from 0.5–2.5 kJ/mm, and interpass temperature should not exceed 150°C. Preheat or post-weld heat treatment is usually unnecessary. Typical filler metals are nickel-overalloyed types like E2209. Welding with carbon steel, other stainless steels, and nickel alloys is also feasible.  

Corrosion Resistance:  This material provides better general corrosion resistance than AISI 316L and 317L. Welded joints readily pass intergranular corrosion tests.  

OTHER TYPES OF DUPLEX STEEL 2205 / S32205 SOCKET WELD FITTINGS