Based on the original 5 t (real 5. 15 t) octagonal ingot mould

with increasing the height of mould from original 1505 mm to 1840 mm

decreasing the taper in the mold walls from 4. 56% to 3. 64%

modifying the hot top location from outside type to inside type and decreasing the ratio of liquid steel in hot top from 15. 15% to 9. 81%

the results of production of Φ210 ~ 300 mm forged products of steel 18CrNiMo7-6

D2 and 30Cr13 by new design 6 t ( real 5. 85 t) ingot mould show that the average yield of 6 t ingot is 86. 47%

as compared with the average yield 79. 71% of 5 t ingot

it increases the yield of products by about 7 point of percentage.