类铅玻璃混合物对白银铸锭的影响

Influence of Mixture Similar to Lead Glass on Silver Ingots

工业生产中出现铸锭凝固面收缩不均匀的情况,导致内部出现缩孔。通过更换坩埚和修改部分参数等,发现采用碳化硅坩埚和合适的保护火焰高度能够有效的解决该问题。通过分析,确定主要因素是坩埚内反应生成类铅玻璃混合物,其在内焰覆盖下温度较低,快速凝固成膜后导致银熔液非均质形核,从而导致凝固面下形成缩孔。另外分析了类铅玻璃混合物的成分类型,并阐述其在熔铸过程中对银锭品质的影响。

In the industrial production, the shrinkage of the casting surface is uneven, which results in the shrinkage of the inner surface. By changing the crucible and modifying the parameters, it is found that the silicon carbide crucible and the appropriate protection flame height can effectively solve the problem. The film which is formed from the mixture leads heterogeneous nucleation of silver. So the shrinkage cavity in the solidification surface is formed. In addition, the component＇s type of lead glass mixture was analyzed, and the influence of the type on silver＇s quality was studied.