Depends on the output quality standard of your product. You can roughly check it with an optical microscope. Ideally a combination of both, optical and electron microscopy.

I think OM can solve the purpose to analyze the quality, if you aren't expecting more details such as quantitative analysis, qualitative mapping etc. Based on your requirements you can plan.

Thanks

It depends entirely on what you mean by "quality"... and what you want to analyze/detect.

For instance, deposits might be detected by light microscopy and/or SEM (depends on nature, size...) ; corrosion and pitting as well but will only be chemically analyzed using an SEM.

And I beg to differ : it CAN be both (separately or even correlated), depending again on what you want to do exactly.