Patent ID: 7820098

Claim:
High Cr ferritic heat resisting steel composition having an enhanced high temperature creep strength consisting of 0.08 to 0.13% of carbon (C), 8.5 to a maximum of 9.81% of chromium (Cr), 0 to 1.5% of molybdenum (Mo), 0.10 to 0.25% of vanadium (V), 0.03 to 0.08% of niobium (Nb), 0.2 to 5.0% of tungsten (W), 1.5 to 6.0% of cobalt (Co), 0.005 to 0.015% of boron (B), 0.015 to 0.025% of nitrogen (N), and 0.01 to 3.0% of rhenium (Re), all represented in terms of the percentage by mass with the remainder iron (Fe) and any unavoidable impurities.