TY - GEN

T1 - Corrosion behaviour of Fe and Ni based alloys in the reactor atmosphere of a thermal cracking process

AU - Schmid, Alexander

AU - Mori, Gregor

AU - Hönig, Stefan

AU - Haubner, Roland

PY - 2018/1/1

Y1 - 2018/1/1

N2 - The alloys 1.7386, 1.4841, 1.4959 and 2.4816 were tested under conditions simulating a thermal cracking process. Tests were performed at 480, 580 and 680 °C, for 24, 72 and 240 h in a gas atmosphere containing 3.8 vol.% HCl, 200 ppm H2S and CO, CO2, H2 and N2. It represents the partial pressures, which are present in the reactor of a thermal cracking process of anthropogenic resources. Flat samples were prepared from pipes and in order to achieve a uniform surface the samples were ground to 1000 grit SiC paper. After corrosion experiments the samples were analyzed by metallography, SEM/EDX and XRD. Additionally the mass loss of the samples during the experiment was evaluated. During corrosion the metallic phase is attacked by HCl and various corrosion products are formed by reaction with CO2 and H2S from the gas phase. After the tests the corroded samples showed a porous multilayered surface structure. The outer layer consisted mainly of Cr sulphide, followed by a Cr oxide layer. Below these two layers an area containing chlorine was detected. The porosity in the corrosion zone can be explained by the evaporation of FeCl2 which was observed as colorless crystals at me colder parts of the testing equipment. This general structure of corrosion products was detected at all tested materials. At high testing temperatures the mass loss decreased with increasing Ni content. However, at lower testing temperatures this effect changed entirely, so that at 480 °C the Ni content showed no influences and the mass losses were nearly equal.

AB - The alloys 1.7386, 1.4841, 1.4959 and 2.4816 were tested under conditions simulating a thermal cracking process. Tests were performed at 480, 580 and 680 °C, for 24, 72 and 240 h in a gas atmosphere containing 3.8 vol.% HCl, 200 ppm H2S and CO, CO2, H2 and N2. It represents the partial pressures, which are present in the reactor of a thermal cracking process of anthropogenic resources. Flat samples were prepared from pipes and in order to achieve a uniform surface the samples were ground to 1000 grit SiC paper. After corrosion experiments the samples were analyzed by metallography, SEM/EDX and XRD. Additionally the mass loss of the samples during the experiment was evaluated. During corrosion the metallic phase is attacked by HCl and various corrosion products are formed by reaction with CO2 and H2S from the gas phase. After the tests the corroded samples showed a porous multilayered surface structure. The outer layer consisted mainly of Cr sulphide, followed by a Cr oxide layer. Below these two layers an area containing chlorine was detected. The porosity in the corrosion zone can be explained by the evaporation of FeCl2 which was observed as colorless crystals at me colder parts of the testing equipment. This general structure of corrosion products was detected at all tested materials. At high testing temperatures the mass loss decreased with increasing Ni content. However, at lower testing temperatures this effect changed entirely, so that at 480 °C the Ni content showed no influences and the mass losses were nearly equal.

KW - HS

KW - HCl

KW - High temperature corrosion

UR - http://www.scopus.com/inward/record.url?scp=85073121684&partnerID=8YFLogxK

M3 - Conference contribution

T3 - European Corrosion Congress, EUROCORR 2018

SP - 44

EP - 58

BT - European Corrosion Congress, EUROCORR 2018

T2 - European Corrosion Congress, EUROCORR 2018

Y2 - 9 September 2018 through 13 September 2018

ER -