Previous Thread
Next Thread
Print Thread
#1550 09/13/21 08:46 PM
Joined: Sep 2021
Posts: 2
J
JZinOH Offline OP
Member
OP Offline
Member
J
Joined: Sep 2021
Posts: 2
Hello all -

It's been quite some time since developing shot peen applications, but now I've been dragged back in. I've got a nickel-based part that will be peened at 4-8A, with the option of S110 or S170 (with CCW equivalent sizes allowed) ... so we'll go with either CCW 14 or CCW 20 ... but which one?

In our other shops with similar parts, the occasionally nagging problem has been edge rollover. The best solution is to generate the largest breakedge (chamfer, radius or whatever the particular requirement is) prior to peening. However, sometimes the max allowed isn't all we'd like it to be.

So the question: Does anyone have any experience as to how much affect shot size has on rollover ... if any ... given that the intensity range must be met regardless?

Thanks,
JZ

Joined: Mar 2021
Posts: 9
Likes: 1
V
Member
Offline
Member
V
Joined: Mar 2021
Posts: 9
Likes: 1
Hi JZ,

This old rollover problem seems to be a never ending one.

In my experience the people machining parts to be shot peened rarely know what "Break Edge Condition" is needed to prevent unwanted rollover, and even If they did, they may not want to incur the extra manufacturing costs involved.

Perhaps If an additional guidance Table (linked to the data provided in Tables 1, 2, 3 & 4) was to be included in ARP7488, resolving the problem may actually get a little closer.

At least the people machining parts could be made aware of what "Break Edge Condition" we (the peeners) need to enable us to meet their requirements.

Here's hoping !

Very Old Tom

Joined: May 1999
Posts: 197
Member
Online Content
Member
Joined: May 1999
Posts: 197
A sharp edge is going to roll regardless of shot size, and a rolled edge is not something you want. in fact its strictly prohibited in most peening specifications and Nadcap requirements dictate you have method for both detecting sharp edges prior to peening and inspecting for rolled edges post peening.
If possible make your edge breaks at least .010", I've found this to be a safe minimum.


Link Copied to Clipboard
Sponsored by Electronics Inc. © 2024 Electronics Inc. All Rights Reserved.
Powered by UBB.threads™ PHP Forum Software 7.7.5