Topic Options
#1393 - 09/26/18 03:41 AM Verification Strips
tec Offline
Member

Registered: 11/01/13
Posts: 55
Can someone please clear up my confusion regarding acceptance test.

Intensity is determined by performing a saturation curve [J443], and coverage by [J2277], which are 2 completely independent processes.

The time required to obtain the coverage of our part is considerably shorter than the T1 time, therefore if we run a verification strip at the part process parameters the arc height will not be the same as what was obtain during the saturation curve. Or should the verification strips be run at the times used to determine the intensity?

If this is the latter, this will impinge on our available manufacturing hours which are already to capacity

Top
#1394 - 09/26/18 08:11 AM Re: Verification Strips [Re: tec]
Jack Champaigne Offline


Registered: 04/20/99
Posts: 313
Loc: Mishawaka, IN, USA
Your statement- 'which are 2 completely independent processes" is key to this question.
To validate intensity you must expose the Almen test strip at (or near) the T1 time derived from the saturation curve. Using shorter exposure times will not give consistent results or reliable information.
The verification strips should be run at the times used to determine the intensity.

Top
#1395 - 09/26/18 08:49 AM Re: Verification Strips [Re: tec]
Walter Offline



Registered: 05/03/99
Posts: 157
Loc: East Hartford, CT, USA
J443 3.5.2
When using a single holder on a fixture, a single strip may be used to verify intensity. This strip should, ideally, be exposed for the time T derived from the saturation curve and its arc height shall be within the stated tolerance. In practice, this is not always possible (for example, when integral values of strokes or rotations are used). When that condition occurs, the value used shall be rounded to the nearest practical time to T. An arc height is then obtained from the intersection of the saturation curve with that nearest practical time of T, see Figure 3. This intersection shall be called a “Target Arc Height”. A single strip subsequently peened for the selected nearest practical time must repeat the target arc height to within ±0.038 mm (0.0015 in ch ) or other value acceptable to the responsible authority.


If you have enough data collected to prove your process is stable and repeatable, perhaps you can supply that information to your customer and extend the intensity verification time?

Top
#1396 - 09/26/18 09:21 AM Re: Verification Strips [Re: tec]
tec Offline
Member

Registered: 11/01/13
Posts: 55
Thanks for the clarification.

Top


Sponsored by Electronics Inc. © 2019 Electronics Inc. All Rights Reserved.