1)The austenite is stable at low carbon contents because of the quantity and combination of austenitizing elements of Chrome and Nickel.
2) There is no martensite start temperature for 316l (kind of a chicken and egg answer, but think about its implications)
3) Martensite is a supersaturated bcc solid solution of carbon in iron. Carbon is too low in these grades to create this supersaturated solution in the first place, let alone transform it diffusionlessly...
Thats my best shot.
Its easy to just say "It can't."
Its a tough sucker to try to explain why, at least this many years away from school.
I'm willing to let someone else take a stab at this.
milo
__________________
People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe
"Almost" Good Answers: