METHOD FOR OBTAINING BORIDE COATINGS FROM BORIC ACID Russian patent published in 2013 - IPC C23C8/70 

FIELD: metallurgy.

SUBSTANCE: boration method of steel parts involves preparation of saturating charge containing boron-containing component and activator - sodium fluoride, packing of parts in a melting pot and heat treatment. As boron-containing component there used is 20-40 wt % of dewatered composition mixture on the basis of boric acid in the form of granules, which are obtained by preparing the mixture containing 70-74 wt % of H₃BO₃, 24-28 wt % of Al and 2 wt % of NaF, dewatering with sintering of the obtained mixture and crushing of sintered composition mixture to the granules with the size of up to 2 mm. Dewatered boric acid being the source of boron at boration is reduced during heat treatment in granules. In addition, saturating charge contains a separation additive, and namely inert powders in the form of aluminium oxide or magnesium oxide, or waste compositions for boration. Saturating charge contains additionally sodium fluoride NaF 2 wt %. Heat treatment is performed at the temperature of 800-950°C during 3-5 hours.

EFFECT: reducing the cost and time of boration, providing additional adjustment of properties and thickness of the obtained coatings, which allows obtaining quality coatings with the specified characteristics.

1 dwg