Chloride limits for pitting and cracking of 300 stainless steels series in an acid gas removal plant
The effect of chloride on the pitting and cracking propagation of UNS S30403 and UNS S31603 exposed to sour service was studied. Laboratory testing to simulate the extreme ends of process conditions found in our acid gases removal plant were conducted. The typical Gas process conditions vary from 110°F (43°C) to 300°F (149°C) with high and low loads of H2S and CO2 in equilibrium with a solution of an acid gas selective solvent and water. This study covered a range of chlorides from 0 to 500 ppm. Cyclic polarization and potentiostatic electrochemical techniques were used to determine the limits of chlorides required to cause stable pitting leading to cracking. Cracking was confirmed by means of 30-days exposure testing of stressed coupon. Conducting cracking testing at several applied stress levels to better resembling applied stresses at the plant piping and vessels are planned. © 2011 by NACE International.
author list (cited authors)
Rincon, H. E., Case, R. P., McIntyre, D. R., & Hernandez, S. R.