SHOT PEENING AND FATIGUE/CFC/SCC
SHOT PEENING AND FATIGUE/CFC/SCC
(OP)
Is there an expert on shot peening and its effects on: stress corrosion cracking, corrosion fatigue, and just pure mechanical fatigue.
I have been to the www.shotpeener.com and combed their library- I got a lot of good information.
However, I was wonder if anyone had any real experience with the process and the beneficial effects that it imparts.
jackboot
I have been to the www.shotpeener.com and combed their library- I got a lot of good information.
However, I was wonder if anyone had any real experience with the process and the beneficial effects that it imparts.
jackboot





RE: SHOT PEENING AND FATIGUE/CFC/SCC
We have used shot peening to increase fatigue life of weld repairs performed on low pressure steam turbine blading and rotating shafts in certain power industry applications.
The main benefit derived from shot peening is the compressive residual stress on the surface of the part. If done correctly, the compressive stress will be uniform and reduce susceptibility to mechanical fatigue crack initiation. I would expect similar resistance to stress corrosion cracking, as well.
NOTE - the benefit of residual stress diminishes as service temperature increases. So, the best situation is when the component that has been shot peened does not see service temperatures that would reduce these beneficial stresses over time. Secondly, coverage of shot peening is critical for success. Inconsistent coverage will result in local residual tensile stresses in the location that you want to protect.
Several of our weld repairs that were shot peened to provide increased fatigue resistance are still in service (with no problems) after 15 years. The initial fatigue failures ocurred within 2 years after being placed into service.
RE: SHOT PEENING AND FATIGUE/CFC/SCC
We have a localized high stress area that will fail- everytime at the same location. Many areas are seal locations so we can't peen everywhere. We did try to cover as much of the critical area as possible. Hopefully, this will fix a headache.
RE: SHOT PEENING AND FATIGUE/CFC/SCC
http://www.shotpeening.org/ICSP/confrns.htm
Click on the papers from the various conferences to access the .pdfs.
RE: SHOT PEENING AND FATIGUE/CFC/SCC
But - it has a good many papers that I have not seen.
RE: SHOT PEENING AND FATIGUE/CFC/SCC
rmw
RE: SHOT PEENING AND FATIGUE/CFC/SCC
= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: SHOT PEENING AND FATIGUE/CFC/SCC
There were cases (solutions) where peening was detrimental though versus a non-peened version.
jackboot
RE: SHOT PEENING AND FATIGUE/CFC/SCC
The most dramatic results were with 430 SS with very small holes. This was a punched hole .0090"dia. in the bottom of 60° coined hole. The resultant hole was surrounded by very tight circular grain boundries and the corrosion mechanism was IGC . By employing shootpeening of this area prior to finishing the hole we practically eliminated the corrosion damage by disconnecting the grain boundries.
Checkout the following site.
http://www.metalimprovement.com/