Non-destructive monitoring of metal hardness is important for process monitoring and product quality assessment. In this paper, a partially hardened metal sample is assessed in regards to physical effects using multi-frequency inductance spectroscopy. For this purpose, the influence of change of conductivity, permeability and stress on the inductance spectra are analyzed. To extract the numerical values of permeability, the measured inductance spectra are compared to the analytical inductance model. Statistical analysis with principal component analysis is conducted to fuse the spectral data into a single representative value. The results show the possibility to obtain information from different layers of the partially hardened sample, thus indicating a strong relationship between the measured inductance and restraint hardening.

金属硬度的无损监测对于过程监测和产品质量评估很重要。在本文中，使用多频电感光谱法评估了部分硬化的金属样品的物理效应。为此，分析了电导率，磁导率和应力的变化对电感谱的影响。为了提取磁导率的数值，将测得的电感谱与分析电感模型进行比较。进行具有主成分分析的统计分析，以将光谱数据融合为单个代表值。结果表明，可以从部分硬化的样品的不同层获取信息，从而表明测得的电感与约束硬化之间存在很强的关系。