| 摘要 |
<p>PURPOSE:To restrain oxygen pickup and to obtain molten metal having high melting point and a little oxygen content by charging the metal having melting point into an induction furnace lined by CaO or MgO based kind refractory and melting in an Ar atmosphere having more than the atmospheric pressure. CONSTITUTION:The metal having high melting point of Ni alloy, Co alloy, Ti, Ti alloy, Cr, Cr alloy, etc., is charged into the induction furnace, which is adjustable to atmosphere therein and lined by CaO kind or MgO kind refractory. After exhausting air in the induction furnace, the Ar atmosphere is made in the furnace and this pressure is held to >=1.2 atmospheric pressure. Under this condition, the above metal having high melting point is heating an melted. By this pressurization of Ar, thermal decomposition of CaO or MgO at high temp. is restrained, to obtain the molten metal having high melting point and reducing oxygen content. It is desirable that time melting is executed from a time as shorter as possible and before the oxygen content in the molten metal reaches to the equilibrium after melt-down, the molten metal is rapidly tapped off and cast.</p> |
