Method for forming a carbide layer of a Va-Group element of the periodic table or chromium on the surface of a ferrous alloy article
AssigneeKabushiki Kaisha Toyota Chuo Kenkyusho
InventorsNoboru Komatsu, Tohru Arai
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Abstract
A method for forming a boron-containing carbide layer on the surface of a ferrous alloy article by dipping the article in a molten bath. The bath is made by introducing boron and an oxide of a Va-Group element or of chromium into molten boric acid or a borate bath. The ratio of the boron to the oxide is between 7% and 40%. The carbide layer formed is very hard and has good oxidation resistance.
Claims41
In a method for forming a carbide layer on an article of carbon-containing ferrous alloy, the following sequential steps:
- (a) preparing a molten (boric acid or borate)/CFE-oxide/(boron-supplying material) treating bath, CFE being a carbide-forming element selected from the group consisting of a Va group element and chromium and the boron-supplying material being one wherein boron is not bound to oxygen,
- (b) immersing the article into the molten treating bath,
- (c) maintaining said article in said molten treating bath for a period sufficient to form a carbide layer of said CFE on the surface of said article and
- (d) removing said article from said molten treating bath.
A treating material for forming a carbide layer on an article of carbon-containing ferrous alloy which is composed of boric acid or a borate, an oxide of CFE, CFE being a carbide forming element selected from the group consisting of a V-a group element and chromium, and a boron-supplying material in which boron is not bound to oxygen.
Dependencies are inferred from the claim text.