Stainless steel is an alloy of Iron with a minimum of 10.5% Chromium. Ordinarily stainless steel is much more resistant to corrosion than ordinary steels BUT it can still corrode.
Some consider SS as more ‘stain-resistant’ than ‘stain-less’.
For instance add too much heat and it will ‘color’ much like lesser steels do.
Can it corrode then?
Yep, acid level PH’s and some chemicals can eat it alive.
Then there is something boat owners know a lot about, Galvanic Corrosion. That’s when two or more dissimilar metals which are in contact with each other and soaked with an electrolyte e.g. water or other solution. To say simply keep the metals apart is the answer isn’t as you often find SS fittings on brass, iron, and lesser steels.
Is stainless non magnetic? Sort of but not fully.
So it’s not very good at sticking to a fridge BUT it will throw a compass out of alignment.
Is stainless good in the extremes of hot and cold?
A special SS called Austenitic is used down to -269 deg Celsius.
Other stainless is OK between general ambient temperatures to 1100 deg Celsius.
Sharpening stainless steel.
Kitchen quality knives will sharpen easily but not hold an edge for long. My Mora camp knife is a classic example of that. I can get it to a VERY keen edge but start cutting hides, shaving wood, or cutting sisal and it soon blunts.
Is there something better? For what is the question?
For beautiful aesthetic appearances I rate , both wootz and pattern-welded Damascus steels which produce a metal that holds an edge well.
For Stain-proof steels (generally better than stainless when coping with corrosion). There are various types.
H1 is used by Spyderco, X15Tn is a French steel.
N680, Bohler-Uddeholm steel, highly corrosion resistant.
N690CO an Austrian stainless steel hardened to the high Rc50 range. (Thank you Wiki)
There is also a steel called evercut.
French, and is steel that has laser-bonded titanium carbide.
It claims it will last 300 times longer then steel.
Never seen the make but am on the look out for one to give it a field craft tryout.
The clue is the steel is BLACK!