Issue 41

G. G. Cunto et alii, Frattura ed Integrità Strutturale, 41 (2017) 332-338; DOI: 10.3221/IGF-ESIS.41.44 332 Application of Leak-Before-Break concept in 316LN austenitic steel pipes welded using 316L Gabriel Giannini de Cunto Navy Technological Center in São Paulo, Brasil gabriel.giannini@gmail.com Arnaldo Homobono Paes de Andrade Nuclear and Energy Research Institute arnaldo.homobono@gmail.com Waldemar Alfredo Monteiro Nuclear and Energy Research Institute wamontei@ipen.br A BSTRACT . The paper presents a study of the application of Leak-Before- Break (LBB) concept in a relatively small-diameter high energy reactor coolant line, where it is proposed type AISI 316LN to be used as base material welded with type AISI 316L coated electrode considering a pipe with diameter of 273 mm. The pipe material was characterized in terms of tensile test with Ramberg-Osgood analyses and fracture toughness tests with J-Resistance curve determination, considering base material, weld joint and heat affected zones. For the mechanical properties found in tensile tests and using the PICEP software, were determined the leak rate curves versus crack sizes, to determine the size of a detectable leakage crack, and the critical crack sizes, considering failure by plastic collapse. For the critical crack sizes found in weld, which presented the lowest toughness, J-Integral analysis was performed considering failure by tearing instability. Results show a well-defined mechanical behavior where base material has a high toughness, weld has a low toughness, and HAZ showed intermediate properties. For the load limit analysis, the lowest critical crack size was found for base material presenting circumferential cracks. For J- Integral analysis, it was demonstrated that failure by tearing instability will not occur. K EYWORDS . Leak-Before-Break; 316LN; Weld 316L. Citation: Cunto, G. G., Andrade, A. H. P., Monteiro, W. A., Application of Leak-Before- Break Concept in 316LN Austenitic Steel Pipes Welded Using 316L, Frattura ed Integrità Strutturale, 41 (2017) 332-338. Received: 11.03.2017 Accepted: 27.04.2017 Published: 01.07.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.