Corrosion and mar resistance of steel components

Patent metadata

Field	Value
Publication number	US-11326259-B2
Application number	US-201816003708-A
Country	US
Kind code	B2
Filing date	Jun 8, 2018
Priority date	Jun 8, 2018
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

A method of improving corrosion and mar resistance of steel components by creating a black magnetite finish, with a medium temperature process, prior to application of a phosphate layer coating.

First claim

What is claimed is:

1. A method of treating a steel component, comprising:
subjecting the steel component to a black oxide treatment; and
after subjecting the steel component to the black oxide treatment, subjecting the steel component to a manganese phosphate treatment that includes a phosphating solution having a temperature of about 180° F., wherein the phosphating solution includes manganese dihydrogenphosphate at about 3 to 4%, phosphoric acid at about 0.7% to 1.4%, manganese nitrate at about 0.1 to 0.7%, and nickel nitrate at about 0.1%.

2. The method of claim 1 , wherein the step of subjecting the steel component to the black oxide treatment includes subjecting the steel component to the black oxide treatment having a temperature of a range of about 210-220° F.

3. The method of claim 2 , wherein the black oxide treatment includes an aqueous solution including sodium nitrate at about 7 to 13% and sodium hydroxide at about 1 to 5%.

4. The method of claim 2 , wherein the black oxide treatment includes an aqueous solution including sodium nitrate and sodium hydroxide.

5. The method of claim 1 , further comprising subjecting the steel component to a grain refining treatment prior to subjecting the steel component to the manganese phosphate treatment.

6. The method of claim 5 , wherein the grain refining treatment includes a grain refining solution having a temperature of about 86° F.

7. The method of claim 6 , wherein the grain refining solution includes tetrasodium pyrophosphate at a concentration of about 2.5 pounds per 100 gallons of water and triethanolamine at a concentration within a range of about 0.4 to 2.5 pounds per 100 gallons of water.

8. The method of claim 1 , further comprising the step of subjecting the steel component to a rust inhibitor treatment.

9. A method of treating a steel component, comprising:
subjecting the steel component to a black oxide treatment; and
after subjecting the steel component to the black oxide treatment, subjecting the steel component to a manganese phosphate treatment that includes a phosphating solution, having manganese dihydrogenphosphate at about 3 to 4%, phosphoric acid 0.7% to 1.4%, manganese nitrate at about 0.1 to 0.7%, and nickel nitrate at about 0.1%.

Assignees

• Snap On Tools Corp

Inventors

• Guedes Ricardo L M

Classifications

• C23C22/62

  Treatment of iron or alloys based thereon · CPC title

• C23G1/08

  Iron or steel · CPC title

• C23C22/83

  Chemical after-treatment · CPC title

• B05D7/14

  to metal, e.g. car bodies (involving a chemical reaction between the metal and the coating C23) · CPC title

• C23F11/1676

  Phosphonic acids · CPC title