1045 Annealed VS Hardened and tempered

[toprem]

In one of our applications a 0.188 thick round washer skipped the heat treat process. It is a 1045 annealed, then stamped, then water quenched to acheive 40Rc and tempered. A few samples however were used just in the annealed condition. This washer is used to preload an input pinion bearing in a marine sterndrive and is sandwiched between the bearing inner race and u-joint bearing face. It will see forces in the axial direction.
I was wondering how the annealed washer would behave differently in comparision to the hardened washer? Any thoughts on its deflection/yeilding?

 

[swall]

You probably should post this question on the transmission and driveline forum. A metallurgist, like myself, will tell you that soft is not as good as hard, but the longevity in your application depends on other factors as well.

 

[israelkk]

The soft can be OK if the stresses are low enough. Can you provide more info on the preload load and the washer area under this preload load. I assume the washer is plated for corrosion protection, if so to my opinion annealed is even better from a hydrogen embrittlement and stress corrosion sensitivity.