process to stress relived the distorted 7075-T6 parts

[ipikus]

Dear Sirs,
We manufactured by machining a parts from 7075-T6 aluminum rod.
Before turning the part, we cut it into 4 sections along the center line, so we created 4 segments that make the complete circle. Then we held them together and machined them by turning.
The part has many sections and different diameters.
After machining, and during a long period of shipping and warehousing, the geometry of the part has “moved” (deformation) and we think it is due to internal stresses.
We have a strong jig that we can force clamp the segments back into the correct shape. What is the correct process to stress relived the distorted parts and bring them back into shape?
If anyone can provide us with this information we are able to perform the repair.

Thanks in advance
ipikus

 

[kumkumvijay]

Hello
My opinion is, its not possible to change the distortion with press for 7075-T6. the distortion must be controlled in quenching and machining process.
The machining might have done with compensation for distortion and appropriate machining technique. If you want to releive the stress then you need to heat treat the part again or do uphill quenching process. these will alter the mechanical properties and lead rejection.

 

[swall]

You could possibly perform a T73 treatment. This is accomplished by taking the product (clamped up in your jig) in the T6 form and re-ageing at 340-360F for 6-8 hours. The product will experience some loss of tensile and yield strength. For rolled bar rather than extruded, re-age for 8-10 hours instead of 6-8 hours.

 

[ipikus]

Thank you kumkumvijay, thank you swall