Shotpeen residue removal
Shotpeen residue removal
(OP)
Hello all,
We manufacture springs and a couple of our jobs require shotpeening. The parts are made from Oil Tempered Chrome Silicon wire. We send the parts through a spray wash cabinet followed by a heated air dry after shotpeening but some shot residue remains and is causing us to fail sediment testing for both particle size and total weight.
Does anyone have any experience with post shotpeen cleaning to remove residue that hides in pockets and crevices?
Thanks in advance for any help you can provide,
Kim
We manufacture springs and a couple of our jobs require shotpeening. The parts are made from Oil Tempered Chrome Silicon wire. We send the parts through a spray wash cabinet followed by a heated air dry after shotpeening but some shot residue remains and is causing us to fail sediment testing for both particle size and total weight.
Does anyone have any experience with post shotpeen cleaning to remove residue that hides in pockets and crevices?
Thanks in advance for any help you can provide,
Kim





RE: Shotpeen residue removal
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RE: Shotpeen residue removal
RE: Shotpeen residue removal
They are fairly big as springs go. Approximately 7" long by 2.5" diameter.
We were wondering if an ultrasonic would loosen and remove the residue. Now we know it should. We are looking to order a small unit to try it out. If we use one for our production requirements I think it might be cost prohibitive? We have never priced a large system before.
RE: Shotpeen residue removal
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P.E. Metallurgy, Plymouth Tube
RE: Shotpeen residue removal
RE: Shotpeen residue removal
EdStainless, we use vib bowls for many other applications here but for this application we need an inline system, not a batch type system. The cleaning station is incorporated into the manufacturing cell and we would need more than one large vibs to keep up with the production requirements.
TVP - we use cast shot and I will have to ask about the possibility of using cut wire. The shot is used to remove residual stress of the steel and the type of shot may be a customer requirement.
RE: Shotpeen residue removal
I'm obviously unfamiliar with your process but I don't believe I've ever seen shotpeening used to remove stress. As it has shot impacting the surface you are typically attempting to impart a compressive residual stress. This compressive stress is beneficial in terms of fatigue life as it will help to keep cracks from forming on the surface.
Aidan McAllister
Metallurgical Engineer
RE: Shotpeen residue removal
One of the beauties of dry Ice pellet blasting is that there is no cleanup required after the fact.
B.E.
You are judged not by what you know, but by what you can do.
RE: Shotpeen residue removal
You are correct about the shotpeen process. I did not describe it correctly. Thanks.
Berkshire, dry ice blasting is something we have discussed for many different applications here. For this particular job it was dismissed due to footprint constraints but I would love to see what it could do for some of our other cleaning projects.
RE: Shotpeen residue removal
Springs are generally formed from material tempered to a very high hardness, IE: 'spring-temper' which includes heat treatment followed by high-strain hardening. Peening should both induce compressive stresses in the surface and 'wash-out' minor surface imperfections that could be embedded stress-risers.
Due to the high hardness spring temper material, cast-steel or steel balls or cut-wire steel shot MUST have high surface hardness, 55-to-62 HRc[example: AMS2431/2, /5, /8]... not regular hardness 45-to-52 HRc. High hardness shot 'should' make it easier to minimize or eliminate surface residue/contamination on high-hardness parts.
NOTE.
For even deeper peening effects with minimal residues, laser-shock peening [example: AMS2546] is beginning to make in-roads in aerospace.
Regards, Wil Taylor
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