METHOD OF IDENTIFYING THROUGH DEFECTS OF POLYMER FILMS DEPOSITED ON METAL PARTS Russian patent published in 2022 - IPC G01N21/88 

FIELD: chemistry.

SUBSTANCE: invention relates to control and determination of through defects of protective surface films applied on metal parts. Method includes bringing the material of the part into interaction with a reagent, at that, as a reagent, which changes the optical properties of the diagnosed section, which are manifested in a change in the colour of the through defect zone in the polymer film on the surface of the metal part, aqueous solution of potassium hexacyanoferrate (III) in hydrochloric acid is used with the following ratio of components in water: from 0.1 to 25 weight fractions, %, of potassium hexacyanoferrate (III), from 5 to 25 weight fractions, %, hydrochloric acid, the part is held for at least 5 minutes in this medium until the visually reproducible moment of appearance of shades of blue colour, which characterizes the beginning reaction of reagent with material of iron part and its alloys on all local zones of presence of through defects in polymer film, after which presence of determined through defect, its location and geometrical parameters are performed.

EFFECT: possibility of determining the presence, location and type of a defect of a polymer protective coating on the surface of a part made from iron and its alloys, while simplifying the process.

1 cl, 1 ex, 2 dwg