Note that stainless steel DOES rust. It is a common misconception that it doesn't.
Stainless steel doesn't STAIN (very easily).
That being said, some grades of SS rust faster than others.
Aluminum doesn't rust.
Many SS pots have an aluminum or chromium oxide finish (i.e. a nonrusting metal blend; also good for heat transfer),
The only metals that do not oxidize (Rust) are platinum and gold. All other metals do oxidize, including Aluminum... Stainless steel has a VERY low oxidation coefficient. I tried to find a graph of the SS corrosion coefficient; however, i couldn't... The SS graph looks like the graph of a cube root. Under normal conditions, it will develop a thin layer a oxidation, and stop oxidizing. This layer of oxidization does not look like rust.. Chromium, is one of the elements that are used to create stainless steel....
If you would like to take the time to read the below article it has a lot of good information in it.
http://www.apv.com/pdf/catalogs/apv_corrosion_handbook_1035_01_08_2008_us.pdf
