PROTECTIVE TECHNOLOGICAL GLASS CERAMIC-TYPE COATING FOR LOW-ALLOY OF UNSTABLE STEELS Russian patent published in 2012 - IPC C21D1/70 

FIELD: metallurgy.

SUBSTANCE: invention relates to steel coatings and may be used in machine building fro protection of large-size billet from low-alloy unstable steels from high-temperature corrosion in hot forming. Coating comprises refractory filler composed of kaolinised fire clay and kaolinite and montnorillonite clay, glass forming component representing alumina-borosilicate glass. Additionally, technical silica is added as refractory filler, nepheline-syenite concentrate is added as glass forming component, and carboxymethyl cellulose is added as binder at the following ratio of components in wt %: alumina-borosilicate glass 23.0-25.0, nepheline-syenite concentrate 14.0-16.0, kaolinised fire clay 38.0-40.0, L3-grade technical silica 18.0-20.0, kaolinite and montnorillonite clay LT-0 3.0-5.0, carboxymethyl cellulose 0.3-0.5. Note here that all materials is sized to pass through sieve with 10000 meshes per cm², while alumina-borosilicate glass features the following chemical composition in wt %: SiO₂ - 70.0±0.5; Al₂O₃ -8.0±0.5; B₂O₃ - 8.0±0.5; CaO - 7.0±0.5; Na₂O - 9.0±0.5.

EFFECT: higher protective technological properties.

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