PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1453–1459 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

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 Dislocation and twinning behaviors in high manganese steels in respect to hydrogen and aluminum alloying Xiaofei Guo a *, Stefan Zaefferer b , Fady Archie c , Wolfgang Bleck a a Steel Institute, RWTH Aachen University, Intze str. 1, Aachen 52072, Germany b Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany c NLMK Europe, Eutelis-Platz 2, Ratingen 40878, Germany The dislocation and twinning evolution behaviors in high manganese steels Fe-22Mn-0.6C and Fe-17Mn-1.5Al-0.6C have been investigated under tensile deformation with and without diffusive hydrogen. The notched tensile tests were interrupted once primary cracks were detected using the applied direct current potential drop measurement. In parallel, the strain distribution in the vicinity of the crack was characterized by digital image correlation using GOM optical system. The microstructure surrounding the crack was investigated by electron backscatter diffraction. Electron channeling contrast imaging was applied to reveal the evolution of dislocations, stacking faults and deformation twins with respect to the developed strain gradient and amount of hydrogen. The results show that t diffusive hydrogen at the level of 26 pp has a conspic ous effect on initiating stacking faults, twin bundles and activating multiple deformation tw ning systems in Fe-22M -0.6C. Eventually, the interactions betwe deformation twins and grain boundaries lead to grain boundary decohesion in th s material. In c mparison, hy rog n does n t obviously affect the microst ucture volution, namely, the twinnin thickness and the amount of ctivated twinning systems in Fe-17Mn-1.5Al-0.6C. The Al-alloyed grade reveals a p s poned nucleation of deformation twins, delayed onset o the secondary twinning system and develops finer twinning lamellae in comparison to the Al-free material. These observations explain the improve resistance to hydrogen induced cracking in Al-alloyed TWIP steels. © 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 f the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Dislocation and twinning behaviors in high manganese steels in respect to hydrogen and aluminum alloying Xiaofei Guo a *, Stefan Zaefferer b , Fady Archie c , Wolfgang Bleck a a Steel Institute, RWTH Aachen University, Intze str. 1, Aachen 52072, Germany b Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany c NLMK Europe, Eutelis-Platz 2, Rati gen 40878, Germany Abstract The dislocation and twinning evolution behaviors in high manganese steels Fe-22Mn-0.6C and Fe-17Mn-1.5Al-0.6C have been investigated under tensile deformation with and without diffusive hydrogen. The notched tensile tests were interrupted once primary cracks were detected using the applied direct current potential drop measurement. In parall l, the strain distribution in the vicinity of the crack was characterized by digital image orr lati n using GOM optical system. The microstructure urrounding t crack was investigated by ele tron backscatter diffracti n. Electron channeling contrast i aging was applied to eveal the evolution of dislocations, stacking faults and deformation twi s with espect to the developed strain gradient and amount of hydrogen. The results show that the diffusive hydrogen at the level of 26 ppm has a conspicuous effect on initiating st cking faults, twin bundles and activat multiple deformati n twinn ng systems in Fe-22Mn-0.6C. Eventually, the int ractions b tween def rm tion twi grain boundari s lead to grai boundary decohesion in this material. I compariso , hydrogen do s o obvi usly aff ct th microstructure volution, namely, the twinning thickness and the amou t of a tivated twinning systems in Fe-17Mn-1.5Al-0.6C. T Al-alloyed g ade reveals a postponed nucleation of deformation twins, delayed ons t of the secondary twinning system and develops finer twinning lamell e in compariso to the Al-fr e material. These observations explain the improved resistance to hydrogen induced cracking in Al-alloyed TWIP steels. © 2018 The Authors. Published by Elsevier B.V. Peer-review under esponsibility of the ECF22 organizers. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: TWIP steels; hydrogen embrittlement; dislocation and twinning behaviors; fracture initiation Keywords: TWIP steels; hydrogen embrittlement; dislocation and twinning behaviors; fracture initiation

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 o ganizers. * Corresponding author. Tel.:+49-241-8095809; fax: +49-241-8092253. E-mail address: xiaofei.guo@iehk.rwth-aachen.de * Corresponding author. Tel.:+49-241-8095809; fax: +49-241-8092253. E-mail ad ress: xia fei.guo@iehk.rwth-aachen.de

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.2018.12.301