Fatigue Design and Evaluation Committee 

Surface Enhancement Division -Unconfirmed Minutes

April 19, 20 & 21, 1999 DaimlerChrysler - Auburn Hills, MI

1) Presentation by Russ Cherenkoff on the Axial Fatigue Performance of Shot Peened 2014-T6 Die Forged Aluminum. A discussion ensued on the use of standard Almen strips for peening aluminum. The potential need for aluminum Almen strips was discussed.

2) Dave Francis presented his computer program of "Simulated Shot Peen Coverage"

3) Dale Lombardo presented his computer program of "Simulated Shot Peen Coverage"

4) Discussion of SAE J2277 Shot Peen Coverage (Dave Francis, sponsor) Jack Champaigne to procure information on replica usage and coverage coupons used in Europe. This was discussed with regard to removal of sections 4.4 and 4.5 of SAE J2277. Otherwise this specification is ready to be sent out for ballot.

5) Dale Lombardo presented a review of software for Almen strip saturation curve plotting. Dale will work with several commercial vendors to develop a SAE standard procedure for use of computer generated saturation curves. (Boeing, British Aerospace, General Electric, Baiker, Progressive Technologies, Metal Improvement Co, and Electronics Incorporated.)

6) Discussion of SAE J442 Jack Champaigne offered the following revisions: a.) Almen strip width was 0.745"-0.750" and will be changed (back) to 0.742"-0.750" b.) Revise the maximum allowable Almen gage indicator tip force from 25 grams to 60 grams.

Surface Enhancement Division consensus approved the changes as suggested.

A discussion by the task group headed by A. Ahmad of the variation in Almen strip performance between various suppliers occurred. Ahmad presented data that suggested slight variation between supplier’s strips. His data was inconclusive and the team agreed to meet to discuss specific experiments to quantify variation between suppliers and identify the causes. Ahmad will convene a meeting of the task group in June or July.

7) Discussion of J2441, Shot Peening (sponsored by D. Hale). Specification to be sent out for ballot.

8) Jack Soules, Cleveland State University, presented his findings on eddy current residual stress measurements. He is able to determine peening intensities non-destructively. An algorithm was being developed to plot residual stress vs. depth profiles.