COMPOSITION FOR GLASS-CERAMIC PROTECTIVE TECHNOLOGICAL COATING Russian patent published in 2009 - IPC C21D1/70 C23C26/00 C03C3/91 

FIELD: chemistry.

SUBSTANCE: present invention pertains to coating compositions for protecting steel and can be used in the machine building industry for protecting big work-pieces made from low-alloyed and low-carbon steel from high-temperature corrosion during process heating before hot treatment with pressure, particularly press forming. The coating composition contains, as refractory filler, quartz sand, clay mineral and kaolinised chamotte. The glass component is in form of datolite concentrate, sodium tripolyphosphate and aluminoborosilicate glass, with the following content of components, in wt %: quartz glass 18.0-20.0, Latnen clay LT - 0.30-4.0, datolite concentrate 14.0-16.0, sodium tripolyphosphate 0.5-1.0, kaolinised chamotte 38.0-40.0, aluminoborosilicate glass 23.0-25.0. All materials of the composition are ground up such that they can pass through a sieve with 10000 openings per cm². The aluminoborosilicate glass has the following chemical content, wt %: SiO₂ 66.0 ± 0.5, Al₂O₃ 12.0 ± 0.5, B₂O₃ 8.0 ± 0.5, CaO 7.0 ± 0.5, Na₂O 7.0 ± 0.5.

EFFECT: reduced loss of metal into slag during thermal treatment and reduced labour and energy inputs for manual or mechanical cleaning of surfaces of steel work-pieces after press forming.

2 tbl