Will a tempering salt pot cause decarb?

Cool. :)
CPM 52100?
Since when does 52100 need to be made from powder? ;) Did you mean E-52100?
I don't know but will guess that since "time at temperature" is a needed component of carbon migration, the answer will be, no.
What are you going to be using to austenitize the steel tho?
Alvin in AZ

alv.. yea, salt pot is the coolest thing i've had for my basement workshop.
CPM does make a 52100 steel.. i have no idea if its a true PM steel or not, i'm not holding my breath for it.. but good 52100 in flat bar stock is hard to find.
I'll be quenching into the hot salt just above Ms temp. I'm using a big knife kiln for the high heat. It's not controlled atmosphere so i must use foil envelopes.. what a paint its going to be tearing those off before quenching.
Project #1 is an AKM receiver.. shooting for 42Rc after Austenetize at 1550 to 1600F (10min) then austemper at 720F for 30min, no temper except 350F paint bake later.. its only 1mm 4130 so i just might miss the 1.2 second pearlite nose if i agitate (think RC boat prop and motor). since its only 720F i can add water too, just a tiny amount while its agitating.
I'd like to try some high heat salt later for a 900F temper from the crazy 2200F aust. temp needed for CPM30V, CPM90V, CPM 3V, etc..
I love those but i'm kind of lost about the optimal hard and tough matrix of steel around carbides to form thin edge.