PSI - Issue 42

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

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 42 (2022) 96–101

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 Abstract Microstructural changes accompanying fatigue of a metastable austenitic steel comprise two main factors: (a) microcracking and (b) nucleation and growth of the martensitic phase. Both factors produce changes in the effective elastic properties that can be monitored by high-precision acoustic techniques. In order to focus on monitoring microcracking, its effect on the elastic properties should be separated from the effect of the martensitic phase, since the latter has elastic constants that are different from the ones of the austenitic phase. To this end, the eddy current technique is used to monitor the volume fraction of martensite. The volume fraction parameter is generally insufficient for the prediction of the elastic properties since they depend not only on the volume fraction but, also, on the shapes of the martensitic particles – that are complex and not fully known. However, if the elastic contrast between the austenitic and martensitic phases is weak-to-moderate, the effect of shapes can be neglected, so that the volume fraction information is sufficient. This allows non-destructive monitoring of microcracking by a combination of the acoustic and the eddy current data. © 2020 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 23 European Conference on Fracture - ECF23 Keywords: microcracking ; damage ; elastic contrast ; crack density ; porosity ; martensitic phase . 23 European Conference on Fracture - ECF23 Fatigue of metastable austenitic steel: Micromechanics aspects Mark Kachanov a,d , Vasiliy Mishakin b,d , Yulia Pronina c,d, * a Tufts University, Medford, MA 02155, USA b Mechanical Engineering Research Institute of RAS – branch of the "Federal Research Center The Institute of Applied Physics of the RAS", 85, Belinskogo str., Nizhny Novgorod, 603024, Russian Federation c Saint Petersburg State University, Universitetskaya Emb. 7–9, St.Petersburg, 199034, Russian Federation d Lobachevsky State University of Nizhny Novgorod, 23 Prospekt Gagarina, Nizhny Novgorod, 603022, Russian Federation

* Corresponding author. Tel./ fax: +7-812-428-44-92. E-mail address: y.pronina@spbu.ru

2452-3216 © 2020 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 23 European Conference on Fracture - ECF23

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.011