LADLE MODIFICATION METHOD OF GREY CAST IRON Russian patent published in 2010 - IPC B22D1/00 C21C1/00 

FIELD: metallurgy.

SUBSTANCE: method involves filling of ladle to 1/3 of its height, introduction of exothermic mixture hardened at 200-300°C to it in quantity of 0.3-0.4%, filling of ladle with molten metal till the volume is full, and mixing during 0.1-0.2 min. Before molten metal is added, to the ladle bottom there added is calcium carbide in quantity of 0.15-0.25% of the weight of poured cast iron. Exothermic mixture includes the following, wt %: 33-55 aluminium alloy in the form of chips; 25-34 iron oxides; 12-17 cryolite; 5-9 ferroboron and 3-7 coal dust.

EFFECT: increasing crack resistance and decreasing residual heat stresses and tendency of cast iron to chilling.

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