PSI - Issue 17

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

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Procedia Structural Integrity 17 (2019) 131–137

ICSI 2019 The 3rd International Conference on Structural Integrity Degradation of microstructure and properties of an AISI 316L steel pipe after more than 100,000 hours usage at 640°C in a petrochemical industry Flavio Pereira de Moraes a , Sandro Francisco Alves Junior a , Ronald Lesley Plaut a , Angelo Fernando Padilha a, * a Departamento de Engenharia Metalúrgica e de Materiais da Escola Politécnica da Universidade de São Paulo (EPUSP), Av. Professor Mello Moraes 2463, Cidade Universitária, 05508-930, São Paulo-SP, Brazil. ICSI 2019 The 3rd International Conference on Structural Integrity Degradation of microstructure and properties of an AISI 316L steel pipe after more than 100,000 hours usage at 640°C in a petrochemical industry Flavio Pereira de Moraes a , Sandro Francisco Alves Junior a , Ronald Lesley Plaut a , Angelo Fernando Padilha a, * a Departamento de Engenharia Metalúrgica e de Materiais da Escola Politécnica da Universidade de São Paulo (EPUSP), Av. Professor Mello Moraes 2463, Cidade Universitária, 05508-930, São Paulo-SP, Brazil. AISI 316L austenitic stainless steel is one of the most widely used in its steel class, especially at high temperature. In this work, samples for analysis were taken from a pipe of AISI 316L with a nominal 200 mm external diameter and 15 mm thick exposed for about 100,700 hours at 640°C with an internal pressure of 4.5 MPa in a reactor of a petrochemical plant. Modifications in the microstructure, mechanical properties and corrosion resistance were investigated and the most significant results are presented. Results show the precipitation of intermetallic phases, mainly sigma phase at grain boundaries and inside the grains. Precipitation caused increased hardness, yield strength and ultimate tensile strength and decreased ductility, toughness and intergranular corrosion resistance. AISI 316L austenitic stainless steel is one of the most widely used in its steel class, especially at high temperature. In this work, samples for analysis were taken from a pip of AISI 316L with a nominal 200 mm external diameter and 15 mm thick exposed for about 100,700 hours at 640°C with an internal pressure of 4.5 MPa i a reactor of a petrochemical pl t. Modifications i the microstructure, mechanical properti s and corrosion resistance were investigated and the most sig ificant results are presented. Results show the precipitation of intermetallic phases, mainly sigma phase t grain boun aries and inside th grai s. Precipitation aused increased hardness, yield strength and ultimate tensile strength and decreased ductility, toughness and intergranular corrosion resistance. Abstract Abstract

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers.

Keywords: Degradation; 316L stainless steel; Microstructure; Mechanical properties; Intergranular corrosion. Keywords: Degradation; 316L stainless steel; Microstructure; Mechanical properties; Intergranular corrosion.

* Corresponding author. Tel.: +55-11-3091-5239; fax: +55-11-3091-5243. E-mail address: padilha@usp.br * Correspon ing author. Tel.: +55-11-3091-5239; fax: +55-11-3091-5243. E-mail address: padilha@usp.br

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers.

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. 10.1016/j.prostr.2019.08.018