Abstract: A high-speed steel obtained by powder metallurgy processing wherein a chemical composition includes, by weight %,C: a quantity (%) which satisfies with the following formula ##EQU1## where Ceq=0.19+0.017 (W+2Mo)+0.22 VN, W, Mo and V are respectively the content (%) in steel______________________________________ Cr: 3-5% V: 6.0-8.5% Mo: 4-7.5% Co: 5-15% W: 5-7% N: 0.2-1.7% ______________________________________and the remainder is Fe, and (W+2Mo) is 15-20% is disclosed.

Abstract: A heat-resisting steel suitable for use in valve parts of internal combustion engine is disclosed, which consists essentially by weight percentage of 0.3-0.5% of C, more than 1.0% to 2.5% of Si, 0.1-2.0% of Mn, 0.5-7.0% of Cr, 0.3-2.0% of Mo and 0.1-1.0% of V as basic ingredients, at least one of 0.3-2.0% of Cu and 0.001-0.05% of REM as sub-ingredients and if necessary, at least one of 0.1 to less than 2.0% of Ni, 0.1-1.5% of W and 0.03-1.0% of Nb+Ta, and the balance of Fe and inevitable impurities.

Abstract: A ferritic alloy steel having good formability, cyclic oxidation resistance and creep strength at elevated temperatures above 1000.degree. F. and particularly above about 1500.degree. F. (816.degree. C.) after a final anneal at 1850.degree. to 2050.degree. F. (1010.degree. to 1120.degree. C.), comprising 0.05% maximum carbon, about 2% maximum manganese, greater than 1.0% to 2.25% silicon, less than 0.5% aluminum, with silicon being at least 3 times the aluminum content, about 6% to about 25% chromium, up to about 5% molybdenum, with the sum of chromium and molybdenum being at least 8%, 0.05% maximum nitrogen, at least one of titanium, zirconium and tantalum, with said titanium, zirconium and tantalum being present in an amount at least equal to the stoichiometric equivalent of the present carbon plus the percent nitrogen, at least 0.1% uncombined columbium, and balance essentially iron.