Sponge-iron alloying
A steel manufacturing process can include forming an iron oxide layer on a hot band during hot rolling; reducing the iron oxide layer on the hot band to form a sponge iron layer that includes pores; the sponge-iron layer having a thickness in a range of about 0.05 μm to about 1000 μm, about 0.1 μm to about 100 μm, or about 5 μm to about 25 μm; and depositing an alloying element into the pores of the sponge iron layer to form an impregnated sponge-iron layer. The process can further include annealing the impregnated sponge-iron layer to produce an iron alloy layer carried by the substrate.
1. An iron admixture layer carried by steel that comprises:
a plurality of iron artifacts adhered to a surface of the steel;
a plurality or continuation of impregnation artifacts disposed between and around the iron artifacts; and
extending from the steel surface a concentration gradient within the iron admixture layer that includes a decrease in iron concentration as a function of distance from the steel surface;
wherein the impregnation artifacts includes one or more iron alloying elements selected from the group consisting of silicon, chromium, manganese, cobalt, nickel, copper, molybdenum, and a mixture thereof.
2. The iron admixture of claim 1 , wherein the plurality of iron artifacts form an iron matrix adhered to the surface of the steel.
3. The iron admixture of claim 2 , wherein the impregnation artifacts are surrounded by the iron matrix.
4. The iron admixture of claim 1 , wherein the impregnation artifacts are plurality of iron alloying elements.
5. An iron admixture layer carried by steel that comprises:
a plurality of iron artifacts adhered to a surface of the steel;
a plurality or continuation of impregnation artifacts disposed between and around the iron artifacts; and
extending from the steel surface a concentration gradient within the iron admixture layer that includes a decrease in iron concentration as a function of distance from the steel surface, wherein the impregnation artifacts are intermetallic particles.