L字交差部を有する平板砂型鋼鋳物の凝固の数値解析

抄録

  Influences of radius and effect on solidification of steel plate casting with “L”junction in sand mold were analyzed by the “Matrix Method” (outer nodal point method), which have already been reported by the authors. It was found that the end effect can not be neglected when the length of the casting is less than about four times the thickness of the plate. In castings longer than about five times the plate thickness, which can be regarded as infinite castings, the minimum inside radius at the junction for the hot spot to be located near the geometric center was estimated to be not one time (conventional standard) but from 1.5 to 2.0 times as large as the plate thickness. Furthermore, the section thickness necessary at the junction to make a shrinkage-free junction was calculated and hot tear at the junction was also discussed. It is also estimated that the maximum mold temperature at the junction can be reduced by 20 to 30°C by increasing the inside radius. For these analysis, conventional inscribed circle method and modulus method are not valid and the error in solidification time calculated by these methods reaches upward of 30% in some cases.