Posted by Steve Kanavas on December 26, 1999 at 11:11:31:
In Reply to: windshield frames posted by Curt K. on December 24, 1999 at 15:02:43:
Curt:
Stainless would be nice, but you will likely find that trying to roll form the complex channeled form will be difficult. 300 series stainless is difficult to roll and retains a lot of residual stresses due to the nickel content of the alloy.
This will result in cracking in the tight bends.
Achieving a full solution anneal by heating to 1900F between operations will indeed relieve these stresses, but you'll see a gross deformation in shape as the working stresses let go.
400 series are heat treatable grades which due to the vanadium content makes the situation worse. Don't use ss alloys like 17ph as they are air hardenable grades which will drive you absolutely nuts.
Try a low carbon steel like a 1008 or 1010 first. Anneal the raw strip at 1600F to lose any mill induced compressive stresses and to make it as soft as possible for your roll forming.
We can dip these in Rustoleum or another RP agent to coat the nooks and crannies, and they will easily last another 50 years.
Steve