ASTM ASME F55 Stainless Steel Pipes & Tubes

ASTM/ASME F55 (UNS S32760) Stainless Steel Pipes & Tubes are super duplex grade products conforming to ASTM A790/A928 standards, featuring a tungsten-enhanced composition (24-26% Cr, 6-8% Ni, 3-4% Mo, 0.5-1.0% W, 0.2-0.3% N) for maximum corrosion resistance (PREN ≥40) and mechanical strength (≥550 MPa yield). This advanced alloy delivers superior performance in extreme offshore, chemical, and subsea environments, offering exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking in chloride-rich and sour service conditions (NACE MR0175 compliant). The tungsten addition enhances stability in welded conditions and improves resistance to uniform corrosion in acidic media, making F55 particularly suitable for umbilicals, heat exchangers, and process piping in aggressive oil/gas, petrochemical, and marine applications where reliability exceeds standard super duplex capabilities. The balanced ferrite-austenite microstructure ensures optimal toughness and fatigue resistance up to 280°C (536°F), providing engineers with a cost-effective alternative to nickel alloys for critical high-pressure systems exposed to seawater, acids, or H₂S-containing environments.