A890 3A

Grade 3A is a duplex stainless steel casting alloy defined by ASTM A890/A890M, engineered for pressure-containing applications that require a combination of high strength, toughness, and excellent corrosion resistance. It contains a balanced mix of chromium, nickel, molybdenum, and nitrogen, forming a dual-phase microstructure that resists pitting, crevice corrosion, and chloride-induced stress corrosion cracking. With slightly lower nickel content and optimized molybdenum and nitrogen levels, Grade 3A provides reliable corrosion performance in brackish water, seawater, and other chloride-rich environments. It is commonly used in marine hardware, chemical process systems, heat exchangers, and offshore structures where strength and corrosion resistance are both critical to long-term performance.