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Passivation and corrosion resistance of stainless steel angles

Time:2022-03-28 Source:Wuxi Jianuo Special Steel Co., Ltd.

Passivation and corrosion resistance of stainless steel angles

The corrosion resistance of stainless steel angles relies heavily on the formation of a uniform dense chromium oxide corrosion resistant layer, often referred to as a passivation layer. It requires a metallurgically clean surface with sufficient chromium content and the provision of oxygen. These requirements can be well met by electrolytic polishing.

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An electrolytically polished surface is a metallically pure surface even showing a slightly richer chromium than the matrix structure.

During the electrolytic polishing process, oxygen is released from the material surface, which leads to the formation of a homogeneous passivation layer soon after the electrolytic polishing process is completed.

Thus the surface of electrolytically polished stainless steel angles clearly shows a better corrosion resistance than surfaces treated by other methods.

For demanding applications such as the pharmaceutical industry, corrosion resistance can be further improved by recently developed chelate passivation technologies such as POLINOX Protect. The organic passivation solution applied to the existing passivation layer forms a stable complex with the substrate, which has the best corrosion resistance.

The best corrosion resistance is obtained by a continuous controlled heat treatment of the passivated layer for 5 minutes at about 150°C.