The resistance of stainless steels to rust or corrosion is accomplished by passivation of the alloy to create a chromium-rich oxide layer. The ESCA technique is an excellent tool to monitor the quality of the stainless steel passivation layer.
To understand the overall ESCA method and how it helps manufacturing needs, please refer to the following:
Electron Spectroscopy for Chemical Analysis of Stainless Steel
Many industries use stainless steel in manufacturing tools, instruments and products. During the manufacturing process, passivation or obtaining a chromium rich layer on the surface of the steel is required to ensure the surface is inert or non-reactive. This keeps the steel from developing corrosion or rust on the surface.
For materials with thin passivation layers, surface analysis is one of the few techniques in providing a chemical analysis of the layer. A common technique for this type of analysis is electron spectroscopy for chemical analysis (ESCA).
The method of this technique utilizes an x-ray beam to excite a solid sample resulting in the emissions of photoelectrons. From these photoelectrons, data on both elemental and chemical contents becomes available for further analysis.
Also called x-ray photoelectron spectroscopy or XPS, the main advantage of this technique is its ability to analyze the surface and chemical state of other materials – including glasses, metals, polymers and other materials.
In the analysis of stainless steel, ESCA provides detailed information for both the chromium-to-iron and the chromium oxide to iron oxide ratios. This information, along with the thickness of the passivation layer is all measured by ESCA.
Learn more about how ESCA is used in stainless steel passivation analysis.