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本文通过分析水平轴离心铸造长／径比小于5的圆筒型铸件的凝固过程，建立了表征铸件凝固过程和二维传热模型．并采用交替陷式差分的方法对离心铸造45#碳钢单材质套筒凝固过程温度场进行了数值计算。结果表明：套筒凝固过程表现为沿径向从靠近模具的铸件外表面层向内表面层、轴向从靠近端盖的铸件层向套筒长度中心部位顺序凝固的特点，模具初温对铸件的凝固速度也有重要的影响。提出减少套筒内表面形成的型腔对外界冷空气的卷吸作用。或在铸件金属浇注完毕后浇注一层低熔点保护渣对保持套筒的这种顺序凝固的特点、以加强最后凝固的内层金属液对外层的补缩作用有一定效果。
In this paper, the solidification process of cylindrical castings with length / diameter ratio of less than 5 was fabricated by centrifugal casting of horizontal shaft, and the characterization of solidification process and two-dimensional heat transfer model were established. The temperature field during the solidification process of 45 # carbon steel single-material sleeve by centrifugal casting was numerically calculated by the method of alternating subsidence difference. The results show that the solidification process of the sleeve is characterized by the radial solidification from the outer surface layer to the inner surface of the casting near the die and the axial solidification from the casting layer near the end cover to the center of the length of the sleeve. The rate of coagulation also has a significant effect. It is proposed to reduce the effect of entrainment of cold air on the outside by the cavity formed on the inner surface of the sleeve. Or pouring a layer of low-melting-point mold flux after casting the cast metal to maintain the orderly solidification of the sleeve, so as to enhance the effect of the final solidified inner-layer molten metal on the outer-layer refilling effect.