COMPOSITION FOR COLD BLACKENING OF METAL PRODUCTS Russian patent published in 2018 - IPC C23C22/50 C23F11/04 

FIELD: technological processes.

SUBSTANCE: invention relates to the field of application of protective-decorative coatings, namely for cold blackening (bluing) of metal products made of steel and cast iron. Invention can be used for decorative finishing of articles obtained by forging, minting, casting and other known methods. Variants of the composition for cold blackening of metal products made of steel and cast iron, one of which includes, mass%: selenium dioxide 3–20, cupric sulfate 1–15, hydrochloric acid (in terms of pure HCl) 0.1–4, distilled water 61–95.9. Another version of the composition for cold blackening of metal products made of steel and cast iron includes, % by weight: selenious acid 3.5–23, cupric sulfate 1–15, hydrochloric acid (in terms of pure HCl) 0.1–4, distilled water 58–95.4.

EFFECT: simplification of the process of cold blackening of metal products from steel and cast iron through the one-stage process implementation with the possibility of simultaneous removal of rust from the surface being treated.

2 cl, 2 ex