Influence of machining parameters on surface roughness and susceptibility to hydrogen embrittlement of austenitic stainless steels Lucas Renato Queiroga a , Gisele Fernanda Marcolino a , Matheus Santos a , Gabriele Rodrigues a , Carlos Eduardo dos Santos b , Pedro Brito a,* a Pontifical Catholic University of Minas Gerais, Department of Mechanical Engineering, Av. Dom Jos e Gaspar 500, 30535-901, Belo Horizonte, (MG), Brazil b Federal Center for Technological Education of Minas Gerais, Av. Amazonas 5253, 30421-169, Belo Horizonte, (MG), Brazil highlights  Surface roughness and microstructure were varied by machining conditions.  Hydrogen embrittlement of stable/metastable austenitic stainless steels was compared.  Presence of surface martensite and microstrains induced hydrogen embrittlement. article info Article history: Received 16 August 2019 Accepted 16 September 2019 Available online 10 October 2019 Keywords: Hydrogen embrittlement Strainless steels Mechanical properties Surface roughness Turning abstract In the present work, an investigation on the susceptibility to hydrogen embrittlement of AISI 304 and 310 austenitic stainless steels was performed. The hydrogen embrittlement process leads to degradation of mechanical properties and can be accelerated by the presence of surface defects combined with elevated surface hardness. Tensile test speci- mens of the selected materials were machined by turning with different cutting parame- ters in order to create variations in surface finish conditions. The samples thus prepared were submitted to tensile tests before and after hydrogen permeation by cathodic charging. Regarding the AISI 304 steel, it was possible to notice that the presence of strain-induced martensite on the material surface led to severe hydrogen embrittlement. In the case of the AISI 310 steel, due to its higher nickel amount, no martensite formation could be detected, and this steel was found to be less susceptible to embrittlement in the tested conditions. © 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction Austenitic stainless steels are FeeCreNi alloys employed in a variety of industries (including, among others, food processing, petrochemical, nuclear, thermo-electric and automotive sectors) because of their elevated ductility, me- chanical strength and excellent corrosion resistance. Recently, these steels have also been considered for hydrogen * Corresponding author. E-mail address: pbrito@pucminas.br (P. Brito). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 44 (2019) 29027 e29033 https://doi.org/10.1016/j.ijhydene.2019.09.139 0360-3199/© 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.