Composition for washing pickled steel plate, method for washing pickled steel plate by using same, and steel plate obtained thereby

Patent metadata

Field	Value
Publication number	US-11332667-B2
Application number	US-202117317317-A
Country	US
Kind code	B2
Filing date	May 11, 2021
Priority date	Dec 18, 2015
Publication date	May 17, 2022
Grant date	May 17, 2022

Abstract

A composition for washing a pickled steel plate and a method for washing a pickled steel plate using the same are provided. The composition for washing a pickled steel plate includes a phosphoric acid ester compound, an amine-based compound, sodium carbonate, ammonium acetate, ethylene diamine tetraacetic acid (EDTA) and a remainder of water, and the method for washing a pickled steel plate is performed using the same.

First claim

The invention claimed is:

1. A composition for washing a pickled steel plate comprising 15 to 24 wt % of a phosphoric acid ester compound, 5 to 15 wt % of citric acid, 2 to 10 wt % of sodium carbonate, 2 to 7 wt % of sodium acetate, 1 to 7 wt % of diethylene tetramine pentaacetic acid (DTPA) and a remainder of water.

2. The composition for washing of claim 1 , wherein the phosphoric acid ester compound is at least one compound selected from the group consisting of bisphenol A-bis(diphenyl phosphate), triaryl phosphate isopropylate, dimethylmethyl phosphate, tetraphenyl m-phenylene bis(phosphate), triethyl phosphate and triphenyl phosphate.

3. The composition for washing of claim 1 , wherein the composition for washing has a pH of at least 8.0.

4. The composition for washing of claim 1 , wherein the composition for washing has a pH of 8.5 to 11.5.

5. The composition for washing of claim 1 , wherein the composition when used for washing is diluted in an amount of 0.05 to 1.5 wt % with water.

6. A method for washing a pickled steel plate, comprising:
preparing a composition for washing a pickled steel plate by mixing 15 to 24 wt % of a phosphoric acid ester compound, 5 to 15 wt % of citric acid, 2 to 10 wt % of sodium carbonate, 2 to 7 wt % of sodium acetate, 1 to 7 wt % of diethylene tetramine pentaacetic acid (DTPA) and a remainder of water;
diluting the composition for washing with water; and
immersing the pickled steel plate in the composition for washing.

7. The method for washing of claim 6 , wherein the diluting the composition for washing with water is performed by diluting 0.05 to 1.5 wt % of the composition for washing with water.

8. The method for washing of claim 6 , wherein the phosphoric acid ester compound is at least one compound selected from the group consisting of bisphenol A-bis(diphenyl phosphate), triaryl phosphate isopropylate, dimethylmethyl phosphate, tetraphenyl m-phenylene bis(phosphate), triethyl phosphate and triphenyl phosphate.

9. The method for washing of claim 6 , wherein the composition for washing has a pH of at least 8.0.

10. The method for washing of claim 6 , wherein the composition for washing has a pH of 8.5 to 11.5.

Assignees

• Posco

Inventors

• Park Rho-Bum
• Song Yon-Kyun
• Park Ji-Hoon
• Yun Hoon
• Choe Seok-Chan
• Ko Kyoung-Pil

Classifications

• C25D5/36

  of iron or steel · CPC title

• C23C28/34

  including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates · CPC title

• C23C28/3225

  with at least one zinc-based layer · CPC title

• C22C38/02

  containing silicon · CPC title

• C23G1/08 Primary

  Iron or steel · CPC title