Effect of Shot Peening on Stress Corrosion Cracking (SCC) of 7075-T6 Aluminium Alloy

Author:  H. Rahmatalla, M. Al-Rimawi, T. Al-Hadid
Source:  Conf Proc: ICSP-6, (p.184-191)
Doc ID:  1996065
Year of Publication:  1996
Abstract:  
Shot Peening, using cast steel particles at different intensities varying from 6-10A was utilised to improve Stress Corrosion Cracking (SCC) of welded 7075-T6 Aluminium alloy. Three-point loaded specimen was used as a necessary technique to evaluate the SCC in chloride enviroment. Specimens were tested in Long Transverse (LT) and Short Transverse(ST) directions. An appreciable improvement due to shot peening, using all intensities was detected in the LT direction. However, Lower SCC resistance improovement in ST direction was obtained when the specimen was shot peened at 8A intensity, only. Other intensities produced apprecialbe improvement. This improvement was attributed to the development of a homogenous compressive layer. The developed layer was able to inhitit, crack iniation and propogation in the low temperature Heat Affected Zone (HAZ) of the welded 7075-T6 Aluminium alloy, where high susceptibility to SCC in unpeened cndition was observed. In this investigation, an experimental program could be predicted using shot peening to improve SCC resistance.