Elevated–temperature mechanical properties and cyclic oxidation resistance of several vvrought ferritic stainless steels

Abstract

Abstract The 1073 and 1273 K tensile stress-rupture, creep properties, and residual room-temperature tensile properties after creep testing, and cyclic oxidation resistance at 1420 K of four thin sheet ferritic stainless steels have been determined. The alloys evaluated included GE 1541 (nominally Fe–15Cr–4Al–1Y), Armco 18 SR (nominally Fe–18Cr–2Al–1Si), and two tantalum modifications of Armco 18 SR containing, nominally, 1·25% tantalum (NASA-18T) or 0·45% tantalum (NASA–18T–A). All four alloys exhibited excellent cyclic oxidation resistance. While some differences exist between the 1273 K tensile and stress-rupture strengths of the various alloys, the 1273 K creep strength of the alloys at slow plastic strain rates (<10−6S−1) are nearly identical. At 1073 K the tensile, stress-rupture, and creep properties of the tantalum-modified alloys are better than those of either Arrllco 18 SR or GE 1541. It appears that in terms of useful creep strength and oxidation resistance, the properties of both tantalum-mod...