ダンプテストによる逆V偏析の直接観察
1977 年 63 巻 1 号 p. 45-52
詳細
1977 年 63 巻 1 号 p. 45-52
A direct observation of “A” segregation in 4 ton sand cast ingots, which had been dumped at 40 and 120min after pouring respectively, was made to discuss the formation mechanism of “A” segregation with the result of temperature measurement into consideration.
The results obtained are as follows:
1) The “A” segregation was found to be formed at the solidification front where the fraction solid was between 0.3 and 0.35, or in the region of lower fraction solid.
2) The interdendritic enriched liquid metal could flow into the strings, even when the fraction solid of the neighborhood was 0.7.
3) The transition of “A” segregation zone to “V” segregation zone in an ingot is caused by a suction effect.
4) The growing direction of primary dendrites in the strings was reverse to the solidification wave in an ingot; i, e. solidification in the strings proceeds outwards from the inside of an ingot.
