Metallurgy/Stress relief of 17-4 Condition H1150
I have quite a few rings that are approximately 16 inches in diameter with a radial wall of .50 inches and a sheet thickness of .070 inches. They have been precipitation hardened to condition H1150 and finish machined. The problem is the rings are up too .025 inches out of flat. I think I can put them between two heavy steel plates and stress relieve them at 1000-1050 deg. F to improve the flatness condition. I'm not sure if this will cause the rings to harden to condition H1050 or not. I don't think so but I'm not the expert. Any help would be appreciated.
As you are assuming, a stress relief operation at a 1050 F subsequent to aging at 1150 F will not make your rings H1050-treated. The reason is that the copper precipitates formed and somewhat coasened at 1150 F will not get finer during the subsequent stress relief.