TY - JOUR

T1 - High-temperature corrosion of austenitic alloys in HCl and H2S containing atmospheres under reducing conditions

AU - Nimmervoll, Manuela

AU - Mori, Gregor Karl

AU - Hönig, Stefan

AU - Haubner, Roland

N1 - Publisher Copyright: © 2022 The Authors

PY - 2022/5/15

Y1 - 2022/5/15

N2 - The corrosion of several Fe-Cr-Ni alloys was examined at 420 °C, 480 °C and 580 °C in reducing atmospheres containing 3.8 vol% HCl and either 0.2 vol% H2S or 2 vol% H2S, denoted as mid-H2S mixture or high-H2S mixture, respectively. The corrosion behavior was compared with the findings achieved during previous studies in an atmosphere containing 3.8 vol% HCl and 0.02 vol% H2S, denoted as low-H2S mixture.Increasing the H2S level accelerated the corrosion of the alloys, particularly at 580 °C. In the low-H2S mixture, the alloying element nickel was identified to be helpful for corrosion protection and the evaporation of metal chlorides played a significant role in the corrosion process. With increasing H2S content conversion processes from metal chlorides to metal sulfides as well as sulfidation processes dominated the corrosion behavior of the tested alloys and chromium was found to be a beneficial alloying element against corrosive attack.In previous studies corrosion models for the low-H2S mixture were already identified. In this paper the effect of rising H2S amount on the corrosion behavior is investigated and a model of the course of corrosion is proposed by considering the role of alloying elements, vapor pressures of metal chlorides and the influence of H2S and HCl.

AB - The corrosion of several Fe-Cr-Ni alloys was examined at 420 °C, 480 °C and 580 °C in reducing atmospheres containing 3.8 vol% HCl and either 0.2 vol% H2S or 2 vol% H2S, denoted as mid-H2S mixture or high-H2S mixture, respectively. The corrosion behavior was compared with the findings achieved during previous studies in an atmosphere containing 3.8 vol% HCl and 0.02 vol% H2S, denoted as low-H2S mixture.Increasing the H2S level accelerated the corrosion of the alloys, particularly at 580 °C. In the low-H2S mixture, the alloying element nickel was identified to be helpful for corrosion protection and the evaporation of metal chlorides played a significant role in the corrosion process. With increasing H2S content conversion processes from metal chlorides to metal sulfides as well as sulfidation processes dominated the corrosion behavior of the tested alloys and chromium was found to be a beneficial alloying element against corrosive attack.In previous studies corrosion models for the low-H2S mixture were already identified. In this paper the effect of rising H2S amount on the corrosion behavior is investigated and a model of the course of corrosion is proposed by considering the role of alloying elements, vapor pressures of metal chlorides and the influence of H2S and HCl.

U2 - 10.1016/j.corsci.2022.110214

DO - 10.1016/j.corsci.2022.110214

M3 - Article

VL - 200.2022

JO - Corrosion science

JF - Corrosion science

SN - 0010-938X

IS - May

M1 - 110214

ER -