Precision Heat-Resistant Steel Valve Castings

4A (2205), as a classic duplex stainless steel, has achieved dual breakthroughs in mechanical properties and corrosion resistance with its "austenite + ferrite" duplex structure and precise composition ratio. 22% chromium is the core of anti-corrosion, which can quickly form a dense Cr₂O₃ oxide film on the material surface, effectively blocking erosion by seawater, chemical media, etc. The 5% nickel element optimizes the dual-phase ratio, making austenite and ferrite each account for 40% to 60%. This not only retains the high strength of ferrite but also possesses the toughness of austenite. Its tensile strength is ≥620MPa and yield strength is ≥450MPa, approximately twice that of ordinary austenitic stainless steel, capable of withstanding mechanical loads under high-pressure conditions. ​ The 3% molybdenum and nitrogen elements work in synergy to significantly enhance the resistance to pitting and crevice corrosion. The pitting equivalent value (PREN) exceeds 34, demonstrating outst…