| 摘要 |
<p>PURPOSE:To obtain an alloy contg. extremely small quantities of O, N, S, by adding powder composed mainly of CaO, and B and/or B2O3 into molten Fe, Co, or Ni base alloy in vacuum or Ar atmosphere to deoxidize, desulfurize, denitride said alloy strongly. CONSTITUTION:Powder composed mainly of CaO, B and/or B2O3 or if necessary further Al are added into the alloy in vacuum or Ar atmosphere. The CaO powder is composed mainly of CaO such as CaO system flux, and CaO-CaF2 powder, etc., are used in addition to CaO powder. By using said additions, a part of Al existing in molten alloy from the beginning or added newly is bonded with O2 in molten alloy to carry out deoxidation. The other part of Al is allowed to react with CaO powder to form Ca and Al2O3. The Ca is converted to CaO, CaS by deoxidation, desulfurization reactions, and the alloy having extremely low contents of O, N, S, and superior creep strength, heat resistance, toughness, weldability and forgeability can be manufactured.</p> |
