I have a theory.
1) i think you are at to Low temp. When austenitizing. Maybe not since there is some variance between suppliers end product and recommended heat treats.
2) i think the use of a propane oven is carbuerizing the steel.
3) the two combined may have created something special here. Id like to see some results of more intensive destructive testing. But it makes sense.
I wonder if anyone has ever done propane vs electric oven testing?
Cheers
OP ha not chosen to return since his last post where he was warned about his repeated insistence of using bad language
