Hydrothermal black oxide conversion coating process for steel components
AssigneeGM Global Technology Operations LLC
InventorsAdam Paul Rabe, Matthew G. Keast, Jacob Alexander Rabe, Zhe Li
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Abstract
Disclosed is a hydrothermal method of coating a part including iron, the hydrothermal method including placing the part including iron in a black oxide conversion solution including at least one oxidizing salt, heating the black oxide conversion coating solution to at least 20° C., and agitating or circulating the black oxide conversion coating solution so that the at least one oxidizing salt reacts with the iron to form a black oxide coating on the part.
Claims20
A method of forming a black oxide coating on an automotive part for an electric drive unit of a vehicle, the method comprising:
- providing an automotive part comprising a body having an outer surface, the automotive part comprising iron;
- placing the automotive part comprising iron in a black oxide conversion coating solution including at least one oxidizing salt;
- heating the black oxide conversion coating solution to a temperature ranging from about 20° C. to 80° C.;
- and
- agitating or circulating the black oxide conversion coating solution for about 20 seconds to about 80 seconds, without subjecting the black oxide conversion coating solution to ultrasonic waves, so that the at least one oxidizing salt reacts with the iron to form a black oxide coating on the automotive part.
A method of forming a black oxide coating on an automotive part for an electric drive unit of a vehicle, the method comprising:
- providing a bearing comprising a body having an outer surface, the bearing comprising iron;
- placing the bearing comprising iron in a black oxide conversion coating solution comprising about 5 weight (wt) percent (%) to about 15 wt % sodium metabisulfite, about 3 wt % to about 15 wt % of a surfactant, and about 0.25 wt % to about 3 wt % citric acid;
- heating the black oxide conversion coating solution to a temperature ranging from about 30° C. to 60° C.;
- and
- agitating or circulating the black oxide conversion coating solution for about 30 seconds to about 60 seconds, without subjecting the black oxide conversion coating solution to ultrasonic waves, to form a black oxide coating on the bearing.
A system for forming a black oxide coating on an automotive part for an electric drive unit of a vehicle, the system comprising:
- a tank having a black oxide conversion coating solution, an agitator having at least of portion thereof in the black oxide conversion coating solution, a heater having at least of portion thereof in the black oxide conversion coating solution, a robot a, and arm and a bearing holder attached thereto, a computing device including an electric process, non-transitory storage media having instructions thereon executable by the electronic processor to carry out functionality comprising:
- providing a bearing comprising a body having an outer surface, the bearing comprising iron;
- placing the bearing comprising iron in the black oxide conversion coating solution comprising at least one oxidizing salt present in about 5 weight (wt) percent (%) to about 20 wt % of the black oxide conversion coating solution;
- heating the black oxide conversion coating solution to a temperature ranging from about 20° C. to 80° C.;
- and
- agitating or circulating the black oxide conversion coating solution for less than 80 seconds, without subjecting the black oxide conversion coating solution to ultrasonic waves, so that the at least one oxidizing salt reacts with the iron to form a black oxide coating on the automotive part.
Dependencies are inferred from the claim text.