PSI - Issue 13

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 Structural Integrity 13 (2018) 219 –2195 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

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2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216 © 2018 V.Pokhmu r skii, M .Khoma, V.Vyna r , Ch,Vasyliv, N.Ratska, T.Vo r onyak I. Stasyshyn. Publishe d by Elsevie r B.V.Pee r r eview un d e r r esponsibility of the ECF22 o r ganize r s. 1. Int r o d uction Investigation of interaction hydrogen with metals allows us to solve the fundamental problems of solid-state physics, physical chemistry and materials science; they are also important for many fields of technology [Karpenko (1962), Pokhmurskyy (1977, 1998), Zhang et al (1997), Murakami (2008), Hirth (1980), Shashkova (2013), Fromm(1980), Choo (1982), Gkowacka (2005), Motomichi (2014)]. Hydrogenation of metals causes changes in the surface layers, reduces their plasticity and increases liability to brittle cracking. The unique feature of hydrogen behavior in iron and steel is a combination of high diffusion mobility, insignificant dissolution and great damaging action. Concentration of hydrogen in the metal can significantly exceed 2452-3216 © 2018 V.Pokhmu r skii, M .Khoma, V.Vyna r , Ch,Vasyliv, N.Ratska, T.Vo r onyak I. Stasyshyn. Publishe d by Elsevie r B.V.Pee r r eview un d e r r esponsibility of the ECF22 o r ganize r s. The concentrations of diffusion-moving and residual hydrogen in steels are determined depending on the carbon content. It is shown that the amount of sorbed hydrogen is determined by the density of dislocations and the relative volume of cementite. After desorption of diffusion-moving hydrogen the microhardness increases and materials plasticity decreases. The change of these characteristics decreases with the increase of carbon content in the steels. Internal stresses increase and redistribute under hydrogen desorption. Fragmentation of ferrite and perlite occurs as a result of electrolytic hydrogenation. Ferrite is characterized by the structure fragmentation and change of the crystallographic orientation of planes. The perlite structure shows the crushing of cementite plates and their destruction. The influence of hydrogen desorption on the microhardness of structural components of ferrite-perlite steels is shown. Large scattering of microhardness is found in perlite, due to different diffusion rates of hydrogen because of the unequally oriented cementite plates. It was found that the tendency of materials to blister formation is reduced with the increase of carbon content. The influence of hydrogen on the tribological behaviour of steels under dry and boundary friction has been studied. It is shown that hydrogen desorption intensifies the materials wear. After hydrogen desorption, tribological behaviour is determined by the adhesion interaction between the contacting pairs. Keywo rd s: Hy dr ogenation; d eso r ption; steel; mic r ost r uctu r e; t r ibology. 1. Int r o d uction Investigation of interaction hydrogen with metals allows us to solve the fundamental problems of solid-state physics, physical chemistry and materials science; they are also important for many fields of technology [Karpenko (1962), Pokhmurskyy (1977, 1998), Zha g et al (1997), Murakami (2008), Hirth (1980), Shashkova (2013), Fromm(1980), Choo (1982), Gk wacka (2005), Motomichi (2014)]. Hydrogenation of metals causes changes in the surface layers, reduces their plasticity and increases liability to brittle cracking. The unique feature of hydrogen behavior in iron and steel is a combination of high diffusion mobility, insignificant is olution a d great damaging action. Concentration of hydrogen in the metal can significantly exceed 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 The influence of hydrogen desorption on micromechanical properties and tribological behavior of iron and carbon steels V.Pokhmurskii, M.Khoma, V.Vynar, Ch,Vasyliv, N.Ratska, T.Voronyak, I. Stasyshyn Ka r penko Physico ‐ M echanical Institute of NAS of Uk r aine, Lviv, 5, Naukova st r ., Lviv, 79601, Uk r ain Abstract The influence of the previous electrolytic hydrogenation on the micromechanical properties and tribological behavior of the surface layers of iron and carbon steels has been studied. The concentrations of diffusion-moving and residual hydrogen in steels are determined depending on the carbon content. It is shown that the amount of sorbed hydrogen is determined by the density of dislocations and the relative volume of cementite. After desorption of diffusion-moving hydrogen the microhardness increases and materials plasticity decreases. The change of these characteristics decreases with the increase of carbon content in the steels. Internal stresses increase and redistribute under hydrogen desorption. Fragmentation of ferrite and perlite occurs as a result of electrolytic hydrogenation. Ferrite is characterized by the structure fragmentation and change of the crystallographic orientation of planes. The perlite structure shows the crushing of cementite plates and their destruction. The influence of hydrogen desorption on the microhardness of structural components of ferrite-perlite steels is shown. Large scattering of microhardness is found in perlite, due to different diffusion rates of hydrogen because of the unequally oriented cementite plates. It was found that the tendency of materials to blister formation is reduced with the increase of carbon content. The influence of hydrogen on the tribological behavi ur of steels under dry and boundary friction has been studied. It is shown that hydrogen desorption intensifies the materials wear. After hydrogen desorption, tribological behaviour is determined by the adhesion interaction between the contacting pairs. ECF22 - Loading and Environmental effects on Structural Integrity The influence of hydrogen desorption on micromechanical p operti s and tribol gical behavior of iron and carbon steels V.Pokhmurskii, M.Khoma, V.Vynar, Ch,Vasyliv, N.Ratska, T.Voronyak, I. Stasyshyn Ka r penko Physico ‐ M echanical I stitute of NAS of Uk r aine, Lviv, 5, Naukova st r ., Lviv, 79601, Uk r aine Abstract The influence of the previous electrolytic hydrogenation on the micromechanical properties and tribological behavior of the surface layers of iron and carbon steels has been studied. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywo rd s: Hy dr ogenation; d eso r ption; steel; mic r ost r uctu r e; t r ibology. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 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. 10.1016/j.prostr.2018.12.142