| 摘要 |
The invention relates to creep-resistant ferritic steel for components subject to high temperatures and particularly for use in high-temperature fuel cells. The invention provides a ferritic chromium steel, which forms an oxide layer based on Cr2O3 on a surface of the steel at temperatures between 600 and 1000°C, the oxide layer protecting an inside of the steel from corrosion, the ferritic chromium steel comprising between 12 and 23 wt% chromium; <=0.1 wt% titanium; and at least one element having oxygen affinity selected from the group consisting of yttrium, lanthanum, zirconium, cerium and hafnium in a total amount between 0.01 and 1 wt%; 0.3 to 0.6 wt% silicon; and an element M that forms a precipitate of an intermetallic phase that is at least one Fe2(M, Si) and Fe7(M, Si)6 wherein M is niobium; silicon and M being present in an amount sufficient to yield a precipitate of an intermetallic phase that is present in the ferritic chromium steel in an amount between 1 and 8 vol%; the balance being iron, the amount of niobium being 0.4 to 1.0 wt%, the amount of aluminum being <0.15 wt%, the mass ratio of Si to M being 0.08 to 1.0, wherein at temperatures between 600°C and 1000°C, the ferritic chromium steel forms a precipitate of an intermetallic phase that is at least one of Fe2(M, Si) and Fe7(M, Si)6, the precipitate of the intermetallic phase being present in the ferritic chromium steel in an amount between 1 and 8 vol%, and the precipitate of the intermetallic phase including between 2 and 15 at% of silicon. |
