PSI - Issue 3

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 3 (2017) 269–275 Available online at www.sciencedirect.com Sci nceDir t Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. Copyright © 2017 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 Scientific Committee of IGF Ex-Co. XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy Analysis of th i tergran lar corrosion susceptibility in stainless steel by means of potentiostatic reactivation tests Francesco Iacoviello*, Vittorio Di Cocco, Laura D’Agostino Università di Cassino e del Lazio Meridionale, DICeM, via G. Di Biasio 43, 03043 Cassino (FR), Italy Abstract Intergranular corrosion cracking in stainless steels is a selective corrosion attack due to a local (grain boundary) Cr depletion. An undesired Cr carbides (Cr 23 C 6 ) precipitation after heat treatment in the sensitization temperature range (usually between 550 and 850°C, depending on the steel chemical composition) is obtained with a kinetics that is mainly influenced by the C content. In thi work, the sensitization susceptibility of four sensitized stainless steels was investigated by means of potentiostatic reactivations tests. In addition, chronoamperometric tests and scanning electron microscope (SEM) observations of the specimens surfaces were performed in order to analyze the evolution of the corrosion morphologies. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. Keywords: Stainless steels; Intergranular corrosion cracking; Potentiostatic reactivation tests. 1. Introduction Intergranular corrosion is a selective attack that initiated and propagates in the vicinity of the grain boundaries of sensitized stainless steels. Cr 23 C 6 carbid s can locally precipitate due to heat treatments or welding procedures with a sensitization temperature that rang s between 550 and 850°C, depending on the steel chemical composition, Outukumpu handbook (2013). This localized corrosion attack is quite difficult to quantify, considering that the weight loss is really low and that the dimensions of the attacked zones are really reduced. The Electrochemical Reactivation Test (EPR test) is able to quantify the stainless steel sensitization degree and its susceptibility to an XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy Analysis of the intergranular corrosion susceptibility in stainless steel by means of potentiostatic reactivation tests Francesco Iacoviello*, Vittorio Di Cocco, Laura D’Agostino Università di Cassino e del Lazio Meridionale, DICeM, via G. Di Biasio 43, 03043 Cassino (FR), Italy Abstract Intergranular corrosion cracking in stainless steels is a selective corrosion attack due to a local (grain boundary) Cr depletion. An u desired C a bides (Cr 23 C 6 ) precipitation aft r heat treatment in the sensitization temperature nge ( su ll betw en 550 and 850°C, depending on the steel chem cal c mposition) is ob ained wi a ki e cs that is mainly influenced by the C content. In this work, the sensitization susceptibility of four sensitized s ainless steels was investigated by means of po iostatic reactivations tests. In addition, chronoamperometric test and scanning electron micro cope (SEM) observatio s the specimens surfaces were performe n rder t analyz the evolution of the corrosion m rphologies. © 2017 The Authors. Publishe by Elsevier B.V. Pe r-r view under es ons bili y of the Scientific Committee of IGF Ex-Co. Keywords: Stainless steels; Intergranular corrosion cracking; Potentiostatic reactivation t sts. 1. Introduction Intergranular corrosion is a selective attack that initiated and propagates in the vicinity of the grain boundaries of sensi ized stainless steels. Cr 23 C 6 carbides can locally precipitate due to h at treatments or weldin proced res with a ation temperature t at ranges between 550 and 850°C, depending on the steel chemical composition, Outukumpu handbook (2013). This localiz d c rrosion attack is quit ifficult o quantify, considering tha the weight loss is really low and that the dim nsions of the attacked zon s are really reduced. The El ctrochemical R activation Test (EPR test) is ble to quantify the stainless steel se sitization degre and its susceptibility to an © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +39.07762993681. E-mail address: iacoviello@unicas.it * Corresponding author. Tel.: +39.07762993681. E-mail address: iacoviello@unicas.it

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2017 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 Scientific Committee of IGF Ex-Co. 10.1016/j.prostr.2017.04.032