LARGE-SIZE INGOT MOLD WORKING SURFACE ALLOYING METHOD Russian patent published in 2006 - IPC B22D27/18 

FIELD: manufacture of large-size ingot molds cast with use of sand-clay mixture.

SUBSTANCE: method for alloying working surface of large -size ingot molds with mass in range 15 - 25 t comprises steps of applying pickup preventing paint onto surface of core of sand-clay mixture; drying core and applying onto it aluminum containing composition. Said composition contains, mass. %: cryolite, 6.0 - 7.0; sodium chloride, 7.5 - 9.1; refractory clay, 10.0 -15.0; potassium chloride, 2.0 - 3.0; sodium bicarbonate, 2.0 - 3.0; aluminum powder, the balance. Content of sodium chloride in relation to cryolite is in range 1.1 - 1.3. Composition with density 1.6 -1.8 g/cm³ is applied at flow rate 1000-1500 g/cm³ onto core having temperature 50 - 100°C . Alloyed layer with thickness 500-700 micrometers containing aluminum up to 20% is formed on ingot mold.

EFFECT: enhanced strength of large-size ingot molds.

1 tbl, 18 ex