By means of quantitative analysis

critical moving diameter and migration law of the gas bubble in the liquid metal were described theoretically in vertical centrifugal field

and equation of the critical moving diameter and movement velocity on the gas bubble was established and verified through the experiment. The results reveal that in vertical centrifugal field

the critical moving diameter is decreased with increasing in centrifugal angular velocity and radius. Movement velocity of the gas bubble is divided into the rising velocity and the centripetal velocity. With the gas bubble moving

both rising velocity and centripetal velocity are increased with the decrease of acceleration. When the resistance force is equal to the power

the acceleration is zero and the movement velocity reaches maximum value

then it is gradually reduced. The resultant movement velocity of the gas bubble is increased with increasing in the centrifugal angular velocity and radius. The higher the centrifugal angular velocity and radius

the more intensive the migration of gas bubble

so the porosity is more difficult to form. Finally

the experimental result is well in agreement with theoretical analysis.