PRODUCTION OF HIGH STRENGTH AUSTENITIC STAINLESS STEEL EXCELLENT IN SEAWATER CORROSION REST STANCE

摘要

PURPOSE: To produce a high strength austenitic stainless steel material excellent in seawater corrosion resistance by subjecting a steel with specific composition to heating up to specific temp., to forging at specific temp. at specific forging ratio, and to cooling in specific conditions. ;CONSTITUTION: The steel has a composition consisting of, by weight, ≤0.08% C, ≤2.00% Si, ≤2.0% Mn, 16-30% Cr, 6-20% Ni, 0.1-3.0% Mo, 0.1-0.5% N, and the balance Fe with inevitable impurities. The steel is heated up to 1100-1300°C and forged at 800-1050°C so that forging ratio becomes ≥1.2. Subsequently, cooling is performed at ≥50°C/min average cooling rate in the temp. region between 800 and 500°C. One or more kinds among ≤2% Cu, ≤0.5% Nb, ≤0.5% Ti, and ≤0.5% Zr are incorporated into the steel. By this method, the austenitic stainless steel material having satisfactory fatigue strength in sea water and suitable for hull construction can be obtained.;COPYRIGHT: (C)1993,JPO&Japio