Supercooling quotient

Characteristic value, determined from the results of thermal analysis of an inoculated cast iron with lamellar graphite compared to the uninoculated state. As supercooling quotient UQ applies the ratio of the absolute supercooling in the inoculated to uninoculated state:


Shows, for example from a thermal analysiscooling curve obtained of a grey cast iron, that here a supercooling of 15 K was measured in the uninoculated state and 6 K in the inoculated state is UQ = 15/6 = 2.5. Optimally, this ratio should be between 1.5 and 2.5. With increasing ratio supercooling increase the number of eutectic cells so that the amount of flake graphite (A-graphite) and the tensile strength is increasing also. Is inoculation too high with UQ > 2.5 is unfavourable because microporosity may occur.

Additional references:
Supercooling
Microporosity
Eutectic cells

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