The distribution of porosity defects can be reduced to the least by using exothermic insulating riser.
采用发热保温冒口，由于冒口的补缩效率提高，缩松倾向明显减少。
2
Based on the principle of volume contraction of freezing, the designing process of riser fitting to the cast steel inserted die with exothermic covering flux has been studied.