中文摘要：

在计算某种刀具材料元素在另一种物质工件材料中的溶解度时，通常需要知道刀具材料中的元素在与工件材料形成的固溶体中的超额自由能，很多数据无文献资料可查，本文介绍了超额自由能的三种计算方法，并用实际算例进行了说明，计算结果对刀具材料的研究和设计提供参考。

英文摘要：

The excess energy of tool materials elements in solid solution with workpiece materials always need to be known when we begin to calculate the solubility, but many dates can not be found in references, so three methods were introduced in this paper, meanwhile the actual examples were used to explain them, the results will provide useful references for tool material design and selection.