METHOD OF APPLYING PROTECTIVE COATING ON STEEL COMPONENTS Russian patent published in 2014 - IPC C23C22/00 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical surface processing of steel components, used in manufacturing products in aircraft construction, shipbuilding and other branches. Method includes application of first layer on steel components, its thermal processing, application of second layer, its thermal processing, after which mechanical processing of second layer is carried out, with first and second layers being applied from the same water suspension, which consists of alumochromophosphate solution and aluminium powder. Water suspension is prepared from the following components, wt %: chrome (III) salt calculated per chrome 0.6-0.0, sodium or potassium hydroxide 1.8-2.6, aluminium hydroxide 17.3-24.0, orthophosphoric acid 17.3-24.0, chrome anhydride 6.9-9.3, aluminium powder 54.4-68.0, water to specific density of alumochromophosphate solution 1.20-1.30 g/cm³. In the process of preparation of said alumochromophosphate solution chrome phosphates are obtained by dissolution of chrome hydroxide in solution of orthophosphoric acid, and aluminium phosphates are obtained by dissolution of aluminium hydroxide in solution of orthophosphoric acid.

EFFECT: invention makes it possible to increase protective ability of obtained coating with simplification of technology of its application and improvement of sanitary and hygienic conditions of labour during preparation of applied alumochromophosphate solution.

4 cl, 3 tbl