【摘要】 对广泛用于铸件缩孔、缩松预测的判据Ｇ／Ｔ＜Ｋ经验公式（常数Ｋ没有任何物理意义）进行了理论推导，得出判据的理论公式为对其物理意义进行了讨论，从理论上解释了判据对厚大型件取上限值，而薄壁件取下限值的原因。文章给出了该判据的应用实例。更多还原

【Abstract】 The criterion for shrinkage cavity and porosity prediction of casting G/ T<K is an empirical formula used widely in practice.However,its physical meaning is not evident and lack of proper dimension relation.On basis o fluid penetration theory,the authors derived the criterion for cavity and porosity defects of casting theoretically as shown below:In addition,its physical meaning is discussed,the reasons why thick-section castings take the bigger critical value and thin-section castings assume the smaller one are clarified.更多还原