PSI - Issue 82

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2026) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 82 (2026) 199–205

© 2026 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 ICSID organizers slow strain rate (10 -6 s -1 ). The nitriding layer and its maximum hardness increased with tempering temperature. However, the nitriding process, although restricted to the surface, provoked an overall decrease of ductility, toughness and mechanical resistance, as measured in the tensile tests. These effects were less pronounced in the specimens nitrided at the lowest temperature (350 o C). © 2026 The Authors. Copy from the contract: 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 ICSID organizers Keywords: supermartensitic stainless steels; plasma ion nitriding; embrittlement 8th International Conference on Structural Integrity and Durability (ICSID2025) Effects of plasma ion nitriding on tensile test curves of supermartensitic stainless steel UNS S41426 L.F. Guedes a , A.R. Pimenta a,b , R.R.M. de Souza c , E.M. de Souza c , J.A.C. Velasco d , S.S.M. Tavares a, * a Universidade Federal Fluminense, Escola de Engenharia, Pós-Graduação em Engenharia Mecânica, Rua Passo da Pátria, 156, (ZIP) 24210 240, Niterói, RJ, Brazil; b Instituto Federal do Rio de Janeiro, Laboratório de Instrumentação e Simulação Computacional LISComp, Rua Sebastião Lacerda, 01, (ZIP) 26600-000, Paracambi, RJ, Brazil; c Universidade Federal do Piauí, Laboratório de Pesquisa e Tratamento por Plasma, Teresina, PI, Brasil; d Instituto Nacional de Tecnologia (INT), Laboratório de H 2 S, Rio de Janeiro, RJ, Brazil Abstract Supermartensitic stainless steels combine high strength with better corrosion resistance than traditional 12%Cr martensitic stainless steels. Nowadays, these materials are used as pipes and accessories in the oil and gas production system, providing good performance with lower cost than duplex/superduplex steels and Ni alloys. Nitriding is a thermochemical treatment employed to increase the surface hardness and wear resistance of steels and other metallic materials. In case of supermartensitic stainless steels, nitriding can improve abrasive wear resistance caused by sand particles present in the oil, gas and produced water. In this work, specimens for tensile tests of UNS S41426 supermartensitic stainless steels were subjected to plasma ion nitriding in 25%N 2 75%H 2 atmosphere with thermal cycles at 350 o C, 400 o C and 570 o C for 5h. Tensile curves of nitride specimens were obtained with

* Corresponding author. Tel.: +55 21 998692302 E-mail address: ssmtavares@id.uff.br (S.S.M.Tavares)

2452-3216 © 2026 The Authors. Copy from the contract: 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 ICSID organizers

2452-3216 © 2026 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 ICSID organizers 10.1016/j.prostr.2026.04.031