PRODUCTION OF IRON-BASED SHAPE MEMORY ALLOY MATERIAL EXCELLENT IN SHAPE MEMORY CHARACTERISTIC

摘要

PURPOSE:To produce an iron-based shape memory alloy material excellent in corrosion resistance, high-temp. oxidation resistance, and shape memory characteristics by subjecting an alloy material having a specific composition consisting of Cr, Si, Mn, Ni, Co, Cu, N, and Fe to specific heating and working. CONSTITUTION:An iron-based shape memory alloy material having a composition consisting of, by weight, 5.0-20.0% Cr, 2.0-8.0% Si, at least one kind among 0.1-14.8% Mn, 0.1-20.0% Ni, 0.1-30.0% Co, 0.1-3.0% Cu, and 0.001-0.400% N, where Ni+0.5Mn+0.4Co+0.06Cu+0.002N=0.67(Cr+1.2Si)=3, and the balance Fe with inevitable impurities is heated up to 1000-1250 deg.C. Subsequently, working is applied to the above alloy material at 400-950 deg.C at 3-50% draft by equivalent plastic strain. By this method, the iron-based shape memory alloy material which has superior high-temp. oxidation resistance as well as corrosion resistance and in which = about 4% amount of recovery strain is attained can be obtained.