I'm not a frequent contributor here but I find myself with some time
and I do happen to have some experience with your topic. I hope my
response helps some. And remember, there are, on occasion, silly
answers, there are no real silly questions if you are honestly
First, using a kiln for heat treatment is pretty standard practice
for many people so your idea of using your kiln is completely valid.
The initial heating parameters that Jorg describes is called
"solution treatment" and is the first step of the annealing process
and, if followed by the second step of immediate quenching, should
produce dead soft (or fully annealed) material. Taking your material
to its fully annealed state is the first process necessary in
successful heat treatment or "age hardening".
I note that you mentioned your material was already dead soft and if
this is the case you may forego the annealing process and move into
the second heating parameters described which are sometimes
referenced as "aging". The neat thing about this for you is that the
heat required for aging or "age hardening" is usually below that
which may produce fire scale so you win twice by not having to do the
anneal process. Not only do you get to skip the first (annealing)
process but flux may be unnecessary for the age hardening stage that
will accomplish your goal of hardening your already dead soft
material. Air cool after the aging step, quenching not necessary.