Trick, don't confuse steel as Steel.
Alloyed may mean different types of alloys, Chrome, Vanadium, etc...
There are literally Thousands of grades. So NO I don't know, however I could find out VERY easily.
I have access to peeps who could bore you to tears ( literally ) in this subject area. I will ask, however you forget, exhaust gas is a complex mix of hydrocarbons, corrosive agents & god knows what else....
Steel is simply not steel, ignore the carbon content, that is about 1/50th of the makeup of a modern steel, grain structure, alloy components, the way the steel is formed, slag content etc...
Anyhow, 316 is way too soft, 316L is just a low carbon version.
All I'd say is that from what I've seen, al stainless ones crack quite readily ( YES< I do agree that the turbo mass needs supporting, bit obvious really, to me anyway ! ).
Lots of MILD steel manifolds as you put it, don't seem to suffer as much..
I'll ask about tomorrow. And as for structural steel, it's cobalt that is added, hence the reason why the fire brigade now need hydraulic equipment to cut people free.
HTH
