Role of grinding induced surface residual stress on probability of stress corrosion cracks initiation in 316L austenitic stainless steel in 3.5% sodium chloride aqueous solution

ABSTRACT

Experimental investigation on the relation of grinding induced surface residual stresses (RS) with stress corrosion cracking (SCC) susceptibility and electrochemical behaviour was conducted on 316L austenitic stainless steel in 3.5% sodium chloride aqueous solution. Grinding was done with the same process parameters to lower the effect of other known parameters on SCC initiation. The corrosion behaviour was characterised by Potentiodynamic and galvanostatic tests. The latest was performed under fixed current density in metastable region. There was a strong relationship between the electrochemical results with RS magnitude. Microscopic investigation showed that the RS induced by grinding could not be the reason for SCC and the dominant defect observed was pitting for all the specimens. The time needed for the breakdown of the passive layer was exponentially related to RS level but the propagation of pits was nearly the same for all the specimens.

KEYWORDS:

• Austenitic stainless steel
• RS
• pitting corrosion
• stress corrosion cracking
• machining

Acknowledgements

Special thanks to Professor Monica Santamaria and Professor Ivano Benedetti for their help in initial preparation and DUEDI S.R.L of Santa Giustina in Colle (Padova, Italy) for their collaboration.

Disclosure statement

No potential conflict of interest was reported by the author(s).