4. Invar manufacturing

although remelting operations (under vacuum or under electrically conductive slag) are sometimes required to improve alloy structure, their use is marginal in the case of Invar and will not be discussed here. Readers wishing to know more about these techniques should consult the manufacturers. Moreover, we shall confine ourselves strictly to the manufacture of Invar itself, and shall not discuss that of its immediate derivatives, some of which require specific thermodynamic paths, particularly as regards the "liquid metal" phase....