PRODUCTION OF HIGH STRENGTH AUSTENITIC STAINLESS STEEL EXCELLENT IN SEAWATER CORROSION RESISTANCE

摘要

PURPOSE:To provide superior seawater corrosion resistance and high fatigue strength in seawater by limiting components in a steel and carrying out controlled rolling and controlled cooling under the conditions suited to the above components, respectively. CONSTITUTION:A stainless steel has a composition consisting of, by weight, =0.08% C, = 2.00% Si, = 2.0% Mn, 21-30% Cr, 10-20%Ni, 0.5-3.0% Mo, 0.3-0.5% N, and the balance Fe with impurity elements. This steel is heated to 1100-1300 deg.C and roughed at = 1050 deg.C at = 50% total reduction of area. Successively, finish rolling is performed at 800-1050 deg.C at = 10% total reduction of area. After rolling, controlled cooling is carried out at = 50 deg.C/min average cooling rate until 800-500 deg.C is reached, by which the recovery of working strain introduced by the finish rolling is inhibited. Further, the precipitation of Cr carbide in the above temp. region is inhibited. By this method, a high strength austenitic stainless steel excellent in seawater corrosion resistance can be obtained.