PSI - Issue 22

Available online at www.sciencedirect.com Available onlin at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 22 (2019) 299–304

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers © 2019 The Authors. Published by Elsevier B.V.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers In this paper, a non-destructive electrochemical method for an evaluation of in-service degradation of brittle fracture resistance of pipeline steels under operation was developed. The low-carbon low-alloyed ferrite-pearlite pipeline steels of gas transit pipelines operated during 25-53 years were investigated. It was shown that mechanical and electrochemical properties of the pipeline steels were deteriorated due to long-term operation. It was found that one of the most sensitive parameter to in-bulk steel degradation among electrochemical properties was polarisation resistance. An acceptable correlation between relative changes in impact toughness and polarisation resistance of steels caused by long-term service was revealed. It was concluded that impact toughness changes of pipeline steels caused by degradation under operation can be evaluated by measurements of changes in their polarisation resistance. Having initial properties of the steel, its current properties can be predicted. The method enables non destructive in-service assessment of degradation degree of pipeline steels. © 2019 The Authors. Published by Elsevier B.V.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers First International Symposium on Risk and Safety of Complex Structures and Components Evaluation of impact toughness of gas pipeline steels under operation using electrochemical method Olha Zvirko a, *, Hryhoriy Nykyforchyn a , Oleksandr Tsyrulnyk a a Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine, Naukova St. 5, Lviv 79060, Ukraine Abstract Natural gas transmission pipelines are an important component of worldwide energy supply. However, many pipelines are near the end of their design life. Long-term operation of pipelines leads not only to an appearance of macro defects but also to in-bulk damaging of pipeline steels at nano- and microscales. A decrease in characteristics of brittle fracture resistance of pipeline steels under long-time operation increases significantly a failure risk. Deterioration of pipelines under operation calls for effective methods for current condition evaluation. In this paper, a non-destructive electrochemical method for an evaluation of in-service degradation of brittle fracture resistance of pipeline steels under operation was developed. The low-carbon low-alloyed ferrite-pearlite pipeline steels of gas transit pipelines operated during 25-53 years were investigated. It was shown that mechanical and electrochemical properties of the pipeline steels were deteriorated due to long-term operation. It was found that one of the most sensitive parameter to in-bulk steel degradation among electrochemical properties was polarisation resistance. An acceptable correlation between relative changes in impact toughness and polarisation resistance of steels caused by long-term service was revealed. It was concluded that impact toughness changes of pipeline steels caused by degradation under operation can be evaluated by measurements of changes in their polarisation resistance. Having initial properties of the steel, its current properties can be predicted. The method enables non destructive in-service assessment of degradation degree of pipeline steels. First International Symposium on Risk and Safety of Complex Structures and Components Evaluation of impact toughness of gas pipeline steels under operation using electrochemical method Olha Zvirko a, *, Hryhoriy Nykyforchyn a , Oleksandr Tsyrulnyk a a Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine, Naukova St. 5, Lviv 79060, Ukraine Abstract Natural gas transmission pipelines are an important component of worldwide energy supply. However, many pipelines are near the end of their design life. Long-term operation of pipelines leads not only to an appearance of macro defects but also to in-bulk damaging of pipeline steels at nano- and microscales. A decrease in characteristics of brittle fracture resistance of pipeline steels under long-time operation increases significantly a failure risk. Deterioration of pipelines under operation calls for effective methods for current condition evaluation.

* Corresponding author. Tel.: +380-32-229-6294; fax: +380-32-264-9427. E-mail address: olha.zvirko@gmail.com

2452-3216 © 2019 The Authors. Published by Elsevier B.V.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review statement: Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers 2452-3216 © 2019 The Authors. Published by Elsevier B.V.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review statement: Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers * Corresponding author. Tel.: +380-32-229-6294; fax: +380-32-264-9427. E-mail address: olha.zvirko@gmail.com

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers 10.1016/j.prostr.2020.01.038