Development of Lean-Alloy Chromium-Nickel Stainless Steels for High Temperature Use

摘要

Three Ti and Ti-B chromium-nickel stainless steels, which displayed optimum high-temperature strength properties, were selected from approx¬imately 150 experimental compositions of the initial study for further metallurgical investigation. Among the properties and variables evaluated were room-temperature tensile and bend characteristics, effects of solu¬tion temperature, finish rolling procedure and section size on the creep-rupture behavior at 1350 and 1500°F, stress-rupture properties at 1600 and 1700℉, strength of welded joints at 1500°F and intergranular corrosion susceptibility following various heat treatments. It was found that finish rolling these steels at temperatures of 1500, 2000,or 2300°F with approx¬imately 10 to 15％ reduction, following a solution treatment at 2300°F, resulted in a pronounced increase in rupture strength at 1350 and l500°F. These increases were accompanied by marked loss of ductility.