Method of preparing oxidation resistant iron base alloy compositions
AssigneeChrysler Motors Corporation
InventorJohn M. Corwin
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Abstract
The method disclosed herein involves the addition of small quantities of elements appearing for the most part in Groups IA, IIA and IIIB of the Periodic Table to the base alloy composition. These elements, as ions, enter into the protective oxide scale and modify predominantly anion and to a lesser extent cation transport through the oxide scale, greatly reducing the amount of oxidation observed due to elevated temperature exposure.
Claims39
A method of preparing an iron-base alloy composition exhibiting improved resistance to oxidation comprising the steps of:
- (a) admixing in a molten state;
- (i) an iron-containing charge;
- (ii) at least one alloy element selected from the group consisting of nickel, chromium, molybdenum, manganese, silicon, carbon, vanadium, cobalt, copper, nitrogen, aluminum, titanium, zirconium and mixtures thereof;
- and
- (iii) an amount of a dopant element sufficient to show a significant and reproducible improvement in one or more oxidation resistant properties of the final composition selected from the group consisting of lithium, sodium, potassium, yttrium, lanthanum, cerium, calcium, magnesium, barium, aluminum, beryllium, strontium, and mixtures thereof;
- and
- (b) allowing the admixture to cool.
A method of preparing an iron-base alloy composition exhibiting improved resistance to oxidation comprising the steps of:
- (a) admixing in a molten state
- (i) iron;
- (ii) at least one alloy element selected from the group consisting of silicon, nickel, chromium, manganese, cobalt, nitrogen, and mixtures thereof;
- and
- (iii) an amount of a dopant element sufficient to show a significant and reproducible improvement in one or more oxidation resistant properties of the final compositions selected from the group consisting of lithium, sodium, potassium, yttrium, lanthanum, cerium, calcium, magnesium, barium, aluminum and mixtures thereof;
- and
- (b) allowing the admixture to cool.
A method of preparing an iron-base alloy composition exhibiting improved resistance to oxidation comprising the steps of:
- (a) providing an iron-containing alloy comprising
- (i) iron;
- and
- (ii) at least one alloy element selected from the group consisting of nickel, chromium, molybdenum, manganese, silicon, carbon, vanadium, cobalt, copper, nitrogen, titanium, zirconium, aluminum and mixtures thereof;
- and
- (b) adding to said iron-containing alloy an amount of a dopant element sufficient to show a significant and reproducible improvement in one or more oxidation resistant properties of the final compositions selected from the group consisting of lithium, sodium, potassium, yttrium, lanthanum, cerium, calcium, magnesium, barium, aluminum, beryllium, strontium and mixtures thereof.
Dependencies are inferred from the claim text.