PURPOSE: To prevent the defects in steel ingots and to improve the yields of slabs and secondary products in an ingot making method by insertion of a mandrel by coating a slag repelling material on the surface of the mandrel and limiting the ratio of the sectional area of the mandrel with respect to a steel ingot and a screw-down ratio.
CONSTITUTION: A mandrel 4 is suspended via a mandrel suspension means 5 at the center in a mold 2 of bottom running, and molten metal is cast. Here, a slag repelling material is coated on the surface of the mandrel 4, and the ratio of the sectional area of the mandrel 4 with respect to a steel ingot is set at ≤7% in casting and making the ingot. The steel ingot contg. the mandrel is rolled at ≤7 screw down ratio with blooming mills to make a slab. The reasons for limiting the ratio of the sectional area of the mandrel and the screw down ratio lie in that with respect to the ratio of the sectional area the adhesiveness between the mandrel and the base material is improved and that with respect to the screw-down ratio the sound slab is obtaind at about 5W7 screw down ratio because of the good adhesiveness between the mandrel and the base material.
| WO/2019/067214 | BI-METAL VALVE BODY CASTING AND METHOD OF MAKING SAME |
| JP2001279367 | ROLL FOR HOT ROLLING MADE BY CENTRIFUGAL CASTING |
ADACHI TAKAHIKO
HONDA KATSUTO
| JPS5532794A | 1980-03-07 |