摘要 |
<p>A solid is added to a molten metal or alloy bath to produce an effect in the fastest possible manner, esp. where the solid has a smaller vol. than the bath and where the effect occurs while the solid is travelling from the bottom to the surface of the bath. The solid consists of a long central section with >=2 side wings designed so no point in the solid is >40 mm., and pref. max. 10 mm., from the surface of the solid, which has the highest possible surface/vol. ratio. The distance between two wings is pref. smaller than the wing width, or vice versa, and the solid is pref: (a) an Fe-Si-Mg alloy added to molten cast iron to obtain nodular graphite; (b) mischmetal added to steel for removing S; (c) Mg and/or Si added to molten Al. The solids (a, b, c) are easily made as sand castings with a standard wt. for simple addn. to a molten metal, in which they are very effective.</p> |