000 01818nab a2200205 4500
005 20260520001102.0
008 260224s2012 xxu
100 1 _aCase, R.P.
_952512
100 1 _aRincon, H.E.
_952513
100 1 _aMcIntyre, D.R.
_952514
245 0 0 _aAnalysis of pit stability in type 316L stainless steel exposed to H2S-saturated dilute chloride solutions above the critical pitting temperature
260 _cmar. 2012
270 _a03/05/2012 ; 03/05/2012
300 _a11 p. ; 035004-1 / 035002-12
520 _aTranscripción del resumen del autor: This study examines the effect of hydrogen sulfide (H2S) on the transition from metastable to stable propagating pits using Type 316L (UNS S31603) steel in brines with Cl- concentrations of 10-3 M to 2 × 10-2 M at 75°C and 150°C. The potentiostatic tests were performed at discrete intervals of 50 mV from the recorded open-circuit potential (OCP) to 300 mV above the OCP. The results based on analysis of the chrono-amperometric transients suggests that the transition to stable pit growth is hindered by H2S saturation at both temperatures. The comparison of the experimental results with similar tests in an acidified control brine (without H2S saturation) indicates that the effect of H2S in the promotion of pit metastability is associated with the diffusion of H2S to the bottom of the cavity. This increases the net anodic current by irreversibly forming metallic sulfides, which, in turn, affect the pit's anolyte by reducing the metal salt concentration. The consequence of this effect is that small pits get activated but seldom reach stability, except when there is a high Cl- concentration within the brine.
581 _a3
773 0 _tCorrosion
_g68
942 _cARTICULO
999 _c187126
_d187126