Method for hardening stainless steel and molten salt bath for realizing said process
AssigneeDurferrit GmbH
InventorsUlrich Baudis, Michael Niedermeyer
Life of this patent
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Abstract
A process for hardening a work piece of stainless steel through diffusion of the elements carbon and/or nitrogen into the work piece surfaces. The work piece is submerged into a molten salt bath and subjected to the molten salt bath for a period ranging from 15 minutes to 240 hours at temperatures below 450° C. In addition to potassium chloride and lithium chloride, the molten salt bath contains an activator substance consisting of barium chloride, strontium chloride, magnesium chloride and/or calcium chloride, and a free or complex cyanide as carbon-donating substance.
Claims16
A process for hardening a stainless steel work piece by diffusing carbon and/or nitrogen into surfaces of the work piece, comprising:
- submerging the work piece into a molten salt bath for a period ranging from 15 minutes to 240 hours and at temperatures below 450° C., wherein the molten salt bath comprises, by weight, the following components:
- 30-60% potassium chloride (KCl),
- 20-40% lithium chloride (LiCl),
- 15-30% an activator substance selected from the group consisting of barium chloride (BaCl2), strontium chloride (SrCl2), magnesium chloride (MgCl2), calcium chloride (CaCl2) and admixtures thereof, and
- 0.2-25% a carbon-donating substance selected from the group consisting of a free cyanide, a complex cyanide and admixtures thereof.
Dependencies are inferred from the claim text.