PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1053–1 58 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Int grity Procedia 00 (2018) 000 – 000

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XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. ECF22 - Loading and Environmental effects on Structural Integrity Effect of vanadium-alloying on hydrogen embrittlement of austenitic high-nitrogen steels Galina Maier* , Elena Astafurova, Valentina Moskvina, Evgeny Melnikov, Sergey Astafurov, Alex d r Burlachenko, Ni a Galchenko Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences, Tomsk, Russia Abstract The effect of hydrogen on tensile behavior and fracture mechanisms of V-alloying and V-free high-nitrogen austenitic steels was evaluated. Two steels with th chemical compositions of Fe-23C – 17Mn – 0.1C – 0.6N (0V-HNS) and Fe-19Cr – 22Mn – 1.5V – 0.3C – 0.9N (1.5V-HNS) were electrochemically hydrogen-charged in NaCl water-solution for 100 hours. According to X-ray diffraction analysis and TEM researches, V-alloying promotes particle strengthening of the 1.5V-HNS. Despite differences in chemical compositions, namely, carbon and nitrogen concentrations, a solid solution hardening is similar for both steels because of precipitate-assisted depletion of austenite by interstitial atoms (carbon and nitrogen) in 1.5V-HNS. For hydrogen-free state, the values of the yield stress and the tensile strength are higher for particle-strengthened 1.5V-HNS as compared to 0V-HNS. Hydrogen-cha ging increases both the yield stress and the tensile strength f the steels, but hydrogen-assisted fracture micromechanisms are different for 0V- NS and 1.5V-HNS. Hydrogen-charging dr stically reduces a total elongation in 0V-HNS but provides insufficient embrittl ment in 1.5V-HNS. Hydrogen-assis ed brittle layers form on lateral surfac s f the specimens, and the widths and fracture micromechanisms in them are different for two ste ls. For 0V-HNS, surface layers f 84 μ m in wid h possess transgranular brittle fr cture mech nis (qu si- leavage mode). For 1.5V-HNS, the brittle surface layers (31 μ m width) destroy in intergranular britt e fracture mode. The central parts of steel specimens show dim le fracture si ila to hydrogen-fre steels. The possible reasons for diff nt hydroge -induced effects in 0V-HNS and 1.5V-HNS are disc ssed. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Effect of vanadium-alloying on hydrogen embrittlement of austeni ic high-nitrogen steels Galina Maier* , Elena Astafurova, Valentina Moskvina, Evgeny Melnikov, Sergey Astafurov, Alexander Burlachenko, Nina Galchenko Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences, Tomsk, Russia Abstract The effect of hydrog n tensile behavior and fracture mechanisms of V-alloying an V-free high-nitrogen austenitic steels was evaluat d. Two steels with he chemic l compositions of F -23Cr – 17Mn – 0.1C – 0.6N (0 -HNS) and Fe-19Cr – 22Mn – 1.5V – 0.3C – 0.9N (1.5V-HNS) were electroc c ly hydro e -charg d in NaCl water-solution for 100 h urs. According to X-ray diffraction analysis and TEM researches, V-alloying promotes particle strengthening of the 1.5V-HNS. Despite ifferences in chemical compo itions, namely, carbon and nitro en conc ntrations, a solid solution hardening is similar for both ste ls be ause of precipitate-a sisted depletion of austenite by interstitial atoms (carbon and nitrogen) i 1.5V-HNS. F hydrogen-free st te, the values of the yi ld stress and the t sile strength are higher for particle-s engthened 1.5V-HNS as compared to 0V-HNS. Hydrogen-c arging increases both the yield stress and t tensile str ngth of th steels, but hydr gen-assisted fracture microm chanisms are differ nt f r 0V-HNS and 1.5V-HNS. Hydrogen-charging drastically r duces a total elongation in 0V-HNS but provides insufficient embrittlement in 1.5V-HNS. ydr gen-assisted b ittle layers form on lateral surfaces of the specimens, an the widths a d fracture micro echanisms in them are diff rent for two s e ls. For 0V-HNS, surface layers of 84 μ m in width possess transgr ula brittle fractur mechanism (quasi-cleavag mode). For 1.5V-HNS, the brittle surface layers (31 μ m width) de troy i inte granular brittle fracture mode. The central p rts of steel specimens show dimple fract e similar to hydrogen-free st els. The possible re sons for differ nt hydrogen-induced effects in 0V-HNS a d 1.5V-HNS are discussed. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High-nitrogen austenitic steels; Particle strengthening; Hydrogen-charging; Fracture; Hydrogen embrittlement. Keywords: High-nitrogen austenitic steels; Particle strengthening; Hydrogen-charging; Fracture; Hydrogen embrittlement.

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 organizers. * Corresponding author. Tel.: +7-903-952-1599; fax: +7(3822)-492-576. E-mail address: galinazg@yandex.ru * Corresponding author. Tel.: +7-903-952-1599; fax: +7(3822)-492-576. E-mail ad ress: galinazg@yandex.ru

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.222