Annealing steel (making it softer) is usually done above 1000F but can be done down to 500Fish. Heating it into the annealing range and cooling properly could change the material properies yes. You wont loose any strength heating it below 500F.
However! The tensile strength of steel does funny stuff at different temps. Heating it to 350F makes it harder to bend!
disclaimer, i just found some random photo online to show what i learned in college. Not saying its 100% right but aligns to materials theory.
Heating to 350F actually makes it harder to bend (175ish C). You have to get past 400C or 750F to even make any benefit at all.
Basically heat it past 1000F and have a risk of ruining the heat treat or keep it at room temp.
A better trick is to take a file and run over where you are bending. If it skates over it is hard and heat treated. I don't know for sure but I DOUBT these bars have any heat treat in them. Maybe a tempering after bending? They are likely heated during bending and possibly annealed or tempered after that to reduce internal stress.
Just my semi educated half guess/assumption. I can't remember what happens to yield strength (bending) but tensile (tearing) does go up as it gets hot.
However! The tensile strength of steel does funny stuff at different temps. Heating it to 350F makes it harder to bend!
disclaimer, i just found some random photo online to show what i learned in college. Not saying its 100% right but aligns to materials theory.
Heating to 350F actually makes it harder to bend (175ish C). You have to get past 400C or 750F to even make any benefit at all.
Basically heat it past 1000F and have a risk of ruining the heat treat or keep it at room temp.
A better trick is to take a file and run over where you are bending. If it skates over it is hard and heat treated. I don't know for sure but I DOUBT these bars have any heat treat in them. Maybe a tempering after bending? They are likely heated during bending and possibly annealed or tempered after that to reduce internal stress.
Just my semi educated half guess/assumption. I can't remember what happens to yield strength (bending) but tensile (tearing) does go up as it gets hot.
