Hello all,

we are meeting serious problem on achieve high MPA ( surface ≥800MPa,0.02-0.05mm≥1200MPa). Our machine is air peening machine. From some pro we should use two kind of medias ( small one for surface, big size for deep). others said that one big one should achieve both.

Does anyone have experince this?

Your inputs are really appreciated!!!

David

Achieving the surface finish with the same size media maybe possible. Try peening first to the desired intensity /coverage, then to significantly lower intensity.

Thanks Walter.

The part is gear for truck.
The spec is 0.35-0.55mm Arc and min 200% coverage
But the important is stress. it must be 800A at surface, 1200MPA at 0.02-0.05mm. This is quite dufficult to decide the process with media.
Have you meet this request before?
What kind of media would you recommend?

Thanks.

Dav

Without knowing all the geometry of the part, I'd go with ASH-330 unless ASH-330 is too large to peen a radii. Yes we do a process like this all the time, but not on gears.

thank you very much, Walter.

You are right. the size ASH-330 maybe too big for the radii.
In your process no problem on 800MPA at surface and 1200MPA at 0.02-0.05mm with ASH-330?

Dav

I don't have experience with this particular material. All I can say is use the largest size you can.

Peening with large shot then smaller diameter also should create the desired effect. But why do that if you can keep the part in the same machine.