A.兩行坩堝中央 B.離爐膛底20~30mm C.爐膛中央 D.離爐膛底10~20mm
A.6min,(815±10)℃ B.6min,(850±10)℃ C.7min,(820±10)℃ D.7min,(850±15)℃
A.(50±2)r/min B.(50±1)r/min C.(100±2)r/min D.(100±1)r/min