ASTM ASME 431 Stainless Steel Pipes & Tubes

ASTM/ASME 431 Stainless Steel Pipes & Tubes are high-strength martensitic (UNS S43100) products conforming to ASTM A213/A268 standards, featuring an enhanced chromium (15-17%) and nickel (1.25-2.50%) composition for superior corrosion resistance and mechanical properties compared to standard 400-series martensitic grades. This premium hardenable alloy achieves exceptional tensile strength (up to 1000 MPa yield after heat treatment) while maintaining better toughness and corrosion resistance than 410/420 grades, particularly in mildly acidic and marine environments. The material's optimized chemistry provides improved resistance to stress corrosion cracking and pitting, making it particularly suitable for high-performance shafts, valves, and pump components in chemical processing, marine engineering, and power generation equipment. While requiring post-weld heat treatment, 431 offers engineers a balanced solution for demanding applications where both mechanical strength and moderate corrosion resistance exceed conventional martensitic stainless steel capabilities, though with reduced low-temperature toughness characteristic of its microstructure.