Abstract
In the period under review, the 18-month immersion experiments and the stress corrosion cracking studies (slow strain rate tests) on three preselected carbon steels (TStE 355, TStE 460, 15 MnNiMo 6.3) in disposal relevant brines at 150 C-170 C were completed. Moreover, first irradiation-corrosion studies were performed on the unalloyed carbon steel TStE 355 in salt brines at 150 C and a realistic gamma dose rate of 10 Gy/h for thick-walled containers. The corrosion results confirm that the low-alloyed steels TStE 460 and 15 MnNi 6.3 are subjected to general corrosion in the brines, and that the linear corrosion rates (56-71 {mu}m/a in NaCl-rich brine, 65-203 {mu}m/a in MgCl{sub 2}-rich brines) imply corrosion allowances acceptable for a thick-walled container. For the submerged arc welded steel specimens, simulating a potential container closure technique, however, severe local corrosion attacks were detected for both steels in the heat-affected zone after testing in the MgCl{sub 2}-rich brines at 150 C. The results obtained from the 100-day experiments under gamma irradiation indicate that a dose rate of 10 Gy/h does not diminish the resistance of the unalloyed steel TStE 355 to pitting corrosion in the brine. In the slow strain rate tests at 170 C
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Citation Formats
Smailos, E, Fiehn, B, Gago, J A, and Azkarate, I.
General corrosion and stress corrosion cracking studies on carbon steels for application in nuclear waste disposal containers.
Germany: N. p.,
1993.
Web.
Smailos, E, Fiehn, B, Gago, J A, & Azkarate, I.
General corrosion and stress corrosion cracking studies on carbon steels for application in nuclear waste disposal containers.
Germany.
Smailos, E, Fiehn, B, Gago, J A, and Azkarate, I.
1993.
"General corrosion and stress corrosion cracking studies on carbon steels for application in nuclear waste disposal containers."
Germany.
@misc{etde_10121757,
title = {General corrosion and stress corrosion cracking studies on carbon steels for application in nuclear waste disposal containers}
author = {Smailos, E, Fiehn, B, Gago, J A, and Azkarate, I}
abstractNote = {In the period under review, the 18-month immersion experiments and the stress corrosion cracking studies (slow strain rate tests) on three preselected carbon steels (TStE 355, TStE 460, 15 MnNiMo 6.3) in disposal relevant brines at 150 C-170 C were completed. Moreover, first irradiation-corrosion studies were performed on the unalloyed carbon steel TStE 355 in salt brines at 150 C and a realistic gamma dose rate of 10 Gy/h for thick-walled containers. The corrosion results confirm that the low-alloyed steels TStE 460 and 15 MnNi 6.3 are subjected to general corrosion in the brines, and that the linear corrosion rates (56-71 {mu}m/a in NaCl-rich brine, 65-203 {mu}m/a in MgCl{sub 2}-rich brines) imply corrosion allowances acceptable for a thick-walled container. For the submerged arc welded steel specimens, simulating a potential container closure technique, however, severe local corrosion attacks were detected for both steels in the heat-affected zone after testing in the MgCl{sub 2}-rich brines at 150 C. The results obtained from the 100-day experiments under gamma irradiation indicate that a dose rate of 10 Gy/h does not diminish the resistance of the unalloyed steel TStE 355 to pitting corrosion in the brine. In the slow strain rate tests at 170 C and 10{sup -4}-10{sup -7} s{sup -1}, a loss of ductility occurred for the steels in an MgCl{sub 2}-rich brine compared to argon. This was probably due to hydrogen embrittlement. However, this effect is not significant and no indication for stress corrosion cracking was found for the hot-rolled steels TStE 355 and TStE 460. On the contrary, the forged steel MnNi 6.3 was susceptible to stress corrosion cracking. (orig./MM) [Deutsch] Im Berichtszeitraum wurden die 18-Monats-Immersionsexperimente und die Spannungsrisskorrosionsuntersuchungen bei langsamen Dehnungsraten an drei ausgewaehlten Staehlen in endlagerrelevanten Salzloesungen bei 150 C-170 C abgeschlossen. Darueber hinaus wurden erste Korrosionsexperimente (100 Tage) an dem unlegierten Stahl TStE 355 in Salzloesungen bei hoher Temperatur (150 C) und einem realistischen Gamma-Strahlenfeld fuer dickwandige Behaelter von 10 Gy/h durchgefuehrt. Die Korrosionsergebnisse an den niedriglegierten Staehlen TStE 460 und 15 MnNi 6.3 nach 18 Monaten Immersion in den drei Salzloesungen (eine NaCl-reich, zwei MgCl{sub 2}-reich) bei 150 C bestaetigen, dass die Grundwerkstoffe bestaendig gegenueber Lochkorrosion sind und dass die linearen Raten der Flaechenkorrosion zu technisch akzeptablen Korrosionszuschlaegen fuer einen dickwandigen Behaelter fuehren. Auch die unterpulvergeschweissten Stahlproben blieben nach 18 Monaten Pruefzeit in der NaCl-reichen Loesung bestaendig gegenueber Lochkorrosion. In den Korrosionsuntersuchungen in einer MgCl{sub 2}-reichen Loesung bei 170 C und Dehnungsraten von 10{sup -4}-10{sup -7} s{sup -1} nahm die Duktilitaet der Staehle gegenueber Argon deutlich ab, was moeglicherweise auf eine H{sub 2}-Versproedung zurueckzufuehren ist. Allerdings war dieser Effekt nicht signifikant und es waren keine Anzeichen fuer eine Spannungsrisskorrosion bei den Staehlen TStE 355 und TStE 460 festzustellen. Der Schmiedestahl 15 MnNi 6.3 hingegen zeigte eine Anfaelligkeit gegenueber Spannungsrisskorrosion. (orig./MM)}
place = {Germany}
year = {1993}
month = {Mar}
}
title = {General corrosion and stress corrosion cracking studies on carbon steels for application in nuclear waste disposal containers}
author = {Smailos, E, Fiehn, B, Gago, J A, and Azkarate, I}
abstractNote = {In the period under review, the 18-month immersion experiments and the stress corrosion cracking studies (slow strain rate tests) on three preselected carbon steels (TStE 355, TStE 460, 15 MnNiMo 6.3) in disposal relevant brines at 150 C-170 C were completed. Moreover, first irradiation-corrosion studies were performed on the unalloyed carbon steel TStE 355 in salt brines at 150 C and a realistic gamma dose rate of 10 Gy/h for thick-walled containers. The corrosion results confirm that the low-alloyed steels TStE 460 and 15 MnNi 6.3 are subjected to general corrosion in the brines, and that the linear corrosion rates (56-71 {mu}m/a in NaCl-rich brine, 65-203 {mu}m/a in MgCl{sub 2}-rich brines) imply corrosion allowances acceptable for a thick-walled container. For the submerged arc welded steel specimens, simulating a potential container closure technique, however, severe local corrosion attacks were detected for both steels in the heat-affected zone after testing in the MgCl{sub 2}-rich brines at 150 C. The results obtained from the 100-day experiments under gamma irradiation indicate that a dose rate of 10 Gy/h does not diminish the resistance of the unalloyed steel TStE 355 to pitting corrosion in the brine. In the slow strain rate tests at 170 C and 10{sup -4}-10{sup -7} s{sup -1}, a loss of ductility occurred for the steels in an MgCl{sub 2}-rich brine compared to argon. This was probably due to hydrogen embrittlement. However, this effect is not significant and no indication for stress corrosion cracking was found for the hot-rolled steels TStE 355 and TStE 460. On the contrary, the forged steel MnNi 6.3 was susceptible to stress corrosion cracking. (orig./MM) [Deutsch] Im Berichtszeitraum wurden die 18-Monats-Immersionsexperimente und die Spannungsrisskorrosionsuntersuchungen bei langsamen Dehnungsraten an drei ausgewaehlten Staehlen in endlagerrelevanten Salzloesungen bei 150 C-170 C abgeschlossen. Darueber hinaus wurden erste Korrosionsexperimente (100 Tage) an dem unlegierten Stahl TStE 355 in Salzloesungen bei hoher Temperatur (150 C) und einem realistischen Gamma-Strahlenfeld fuer dickwandige Behaelter von 10 Gy/h durchgefuehrt. Die Korrosionsergebnisse an den niedriglegierten Staehlen TStE 460 und 15 MnNi 6.3 nach 18 Monaten Immersion in den drei Salzloesungen (eine NaCl-reich, zwei MgCl{sub 2}-reich) bei 150 C bestaetigen, dass die Grundwerkstoffe bestaendig gegenueber Lochkorrosion sind und dass die linearen Raten der Flaechenkorrosion zu technisch akzeptablen Korrosionszuschlaegen fuer einen dickwandigen Behaelter fuehren. Auch die unterpulvergeschweissten Stahlproben blieben nach 18 Monaten Pruefzeit in der NaCl-reichen Loesung bestaendig gegenueber Lochkorrosion. In den Korrosionsuntersuchungen in einer MgCl{sub 2}-reichen Loesung bei 170 C und Dehnungsraten von 10{sup -4}-10{sup -7} s{sup -1} nahm die Duktilitaet der Staehle gegenueber Argon deutlich ab, was moeglicherweise auf eine H{sub 2}-Versproedung zurueckzufuehren ist. Allerdings war dieser Effekt nicht signifikant und es waren keine Anzeichen fuer eine Spannungsrisskorrosion bei den Staehlen TStE 355 und TStE 460 festzustellen. Der Schmiedestahl 15 MnNi 6.3 hingegen zeigte eine Anfaelligkeit gegenueber Spannungsrisskorrosion. (orig./MM)}
place = {Germany}
year = {1993}
month = {Mar}
}