Alternative to Shotpeening
Alternative to Shotpeening
(OP)
I have a customer which we manufacture springs that get shotpeened and the customer is having issues with the shot media getting wedged in between the last active coil and closed coil. The spring is used in a hydraulic pump and they do not what any foreign material that could cavitate the pump. Does anyone know of a different shotpeening method that doesn't use shot media?





RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
wire diameter range .125 to .250
RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
like as btrueblood stated. Customer likes this method but does not want to pay for it. I would like to try to redesign the springs so they would not need to be shotpeened, this maybe the easier route.
RE: Alternative to Shotpeening
Well, probably not acceptable to the customer, as the fatigue life would suffer.
But how about redesigning the spring so that the last turn is not "fully closed", i.e. doesn't rest against the next turn? If the spring is guided in its travel, it is unlikely that the fully closed condition is a design requirement.
RE: Alternative to Shotpeening
Thanks again
RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
Here is paper with a little information on shot size.
http://
RE: Alternative to Shotpeening
You might want to check out the Badger Metal site. They use fine penning or nitriding or combination of the two to improve tool life.
http://www.badgermetal.com/extras/extras.htm
RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
Do you know anyone in the Chicago-land area that does laser shock peening? Also do you where I can find any literature about the process?
Thanks for the info
RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
We performed life cycle testing with just presetting the springs and could not achieve 10mm life cycles.
RE: Alternative to Shotpeening
RE: Alternative to Shotpeening
Dimentions
First load point
Second load point
Number of active and total coils
Type of ends
Material specifications
Did you check wire surface conditions after coiling (Nicks, Scratches, Dents, Tool markings, etc.?
RE: Alternative to Shotpeening
You might also want to search the library at ShotPeener.com.
I looked into laser peening as an alternative to shot peening, but the cost was day and night compared to shot peening.
RE: Alternative to Shotpeening
If fatigue is a concern with your spring then the spring should have the last coil closed and ground square, if you leave the end plain and not closed then the load applied will be eccentric to some degree and result in a higher stress for a given load on that spring.
Israelkk's idea sounds very good to me using preset.
desertfox
RE: Alternative to Shotpeening
Let me know your thoughts
RE: Alternative to Shotpeening
Is the spring accepts electro chemical coating such as zinc? If it does check for hydrogen embrittlement correct removal process.
With regard to preset you need to calculate for maximum available cold working to get the most of the preset process.