Is stress relief for SST 316 requried?

[UchidaDS]

I have a 316 SST disk and is about .33". It has a thin lip at the edge which is about .04" (see attached). It meet the spec of flatnees .002 at the lip area, but there is no stress relief call out before or after machining.
Note that the puspose of this disk will expose to a temperature about 300-deg C for 15 sec.
Will this effect the flatness significantly?

 

[EdStainless]

Distortion will likely be most impacted by the uniformity of heating.
If you want it flat I would rough machine and then temp cycle them a few times, and then final machine.

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