Effect of valine and glycine as environmentally safe inhibitors on dissolution of α-Aluminum Bronze in sulfide polluted saltwater: Electrochemical and stress corrosion cracking study

Herein,the inhibiting effect of valine and glycine to suppress the dissolution of α-aluminum bronze (cu7al) alloy,in chloride electrolyte with and without sulfide ions was studied. different techniques were used such as potentiodynamic polarization,electrochemical impedance spectroscopy (eis),electrochemical frequency modulation (efm) and stress corrosion cracking (scc) using the constant slow strain rate technique (ssrt). the surface morphology was examined using sem and edx to evaluate the effect of studied inhibitors. the protection of α-aluminum bronze is attributed to the formation of protective film of the amino acids on the alloy surface which decreases in presence of sulfide ions due to the incorporation of sulfur in the protective film and the corrosion increases. sem and edx results confirmed the presence of protective layer on the alloy surface in presence of the studied amino acids. the presence of valine and glycine changes the failure mode from brittle transgranular cracking to ductile failure. the data obtained from potentiodynamic polarization,eis and efm are in good agreement with ssrt results. © 2017,university of mohammed premier oujda morocco.