PSI - Issue 17

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

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Procedia Structural Integrity 17 (2019) 230–237

ICSI 2019 The 3rd International Conference on Structural Integrity Investigation of mechanical properties and microstructure of X60 line-pipe steel Jan Kec a * , Ivo Černý a , Adam Poloch a , Barbora Kyselá a , Miloslav Poupa a , Romana Pavelková b , Jiří Janovec c a SVÚM a.s., Strength Department, Tovární 2053, 250 88, Čelákovice, Czech Republic b NET4GAS , s.r.o., Na Hřebenech II 1718/8, 140 21, Praha 4 - Nusle, Czech Republic c Czech Technical University in Prague, Faculty of Mechanical Engineering, Department of Material Engineering, Karlovo náměstí 13, 120 00, Praha 2, Czech Republic ICSI 2019 The 3rd International Conference on Structural Integrity Investigation of mechanical properties and microstructure of X60 line-pipe steel Jan Kec a * , Ivo Černý a , Adam Poloch a , Barbora Kyselá a , Miloslav Poupa a , Romana Pavelková b , Jiří Janovec c a SVÚM a.s., Strength Department, Tovární 2053, 250 88, Čelákovice, zec e lic b NET4GAS , s.r.o., Na Hřebe ech II 1718/8, 140 21, Praha 4 - Nusl , Czech Republic c Czech Technical University in Prague, Faculty of Mechanical Engineering, Department of Material Engineering, Karlovo náměstí 13, 120 00, Praha 2, Czech Republic

Abstract Abstract

A segment of seam pipeline with an outer diameter (OD) 813 mm and wall thickness (WT) 10,6 mm, operating since 1974, was used for investigation of its mechanical properties and microstructure. The results of the tensile test show that nominal values of minimum yield point, ultimate tensile strength and ductility were reached in all specimens. Charpy V-notch test was carried out on base metal, heat affected zone and seam weld at temperatures 40, 20, 0, -20, -40 and -60 °C. In case of base metal, L-T orientation showed higher upper shelf energy (USE) and ductile-brittle transition temperature (DBTT) than T-L orientation than is typical for hot-rolled material. The lowest impact energy was measured in the heat affected zone and seam weld due to the presence of heterogeneous microstructure consisting of grain boundary ferrite, polygonal ferrite and Widmanstätten ferrite. A segment of seam pipeline with an outer diameter (OD) 813 mm and wall thickness (WT) 10,6 mm, operating since 1974, was used for investigation of its mechanical properties and microstructure. The results of the tensile test show that nominal values of mini um yield point, ultimate tensile strength and ductility were reached in all specimens. Charpy V-notch test was carried out on base metal, heat affected zone and seam weld at temperatures 40, 20, 0, -20, -40 and -60 °C. In case of base metal, L-T orientation showed higher upper shelf energy (USE) and ductile-brittle transition temperature (DBTT) than T-L orientation than is typical for hot-rolled material. The lowest impact energy was measured in the heat affected zone and seam weld due to the presence of heterogeneous microstructure consisting of grain boundary ferrite, polygonal ferrite and Widmanstätten ferrite.

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. Keywords: Pipeline steel, X60 API 5L, L415N, Charpy impact test, Tensile test; Keywords: Pipeline steel, X60 API 5L, L415N, Charpy impact test, Tensile test;

* Corresponding author. Tel.: +420 326 509 044. E-mail address: kec@svum.cz * Corresponding author. Tel.: +420 326 509 044. E-mail address: kec@svum.cz

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers.

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. 10.1016/j.prostr.2019.08.031