PFHT Solution annealing with different time/temperature of base material

[ElCidCampeador]

thread292-481216

Hi, I've a similar question of thread below.

In this case I have 2 different spheres mat.316, 30 and 35mm, whose starting disks (cut from plate) will be hot formed and then solution annealed with PFHT.

In the first one mill certificate, base material was solution annealed at 1100°C for 30min (1 minute per mm=30min); in the second one, base material was solution annealed at 1060 for 90 min.

My supplier wants to do only one PFHT for both formed spheres at 1100°C for 35min (to save money). Which means with time lower than one of base material of second sphere. Do you think it's a good idea from a metallurgical point of view?

The other option is to do at 1100°C for 90min (which would cover the worst both condition for time/temperature), but in this case there's a chance that mechanical properties of first sphere will drop too much (this starting plate has already low yield and tensile strength).

Do you think that what my supplier would do (PFHT at 1100°C for 35min) is contestable by anyone?

 

[EdStainless]

The material is already annealed.
Since this post forming you are really just after strain relief.
I don't see why 1100 x 35 would not work fine.
Getting reasonably rapid uniform cooling is the real trick with this HT.

Though those times are both short for a real anneal by my way of thinking.
There should be some allowance for heat up time prior to hold.

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P.E. Metallurgy, consulting work welcomed