Characterization of hydrogen induced cracking in TRIP-assisted steels. (21st December 2015)

• Record Type: Journal Article
• Authors: Laureys, A.; Depover, T.; Petrov, R.; Verbeken, K.
• Is Part Of: International journal of hydrogen energy. Volume 40:Number 47(2015)
• Page Start: 16901
• Page End: 16912
• Publication Date: 2015-12-21
• Subjects: TRIP-assisted steel -- Hydrogen embrittlement -- Mechanical properties -- Tensile tests -- Hydrogen induced cracking -- SEM; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.06.017
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The present work evaluates hydrogen induced cracking in a TRIP-assisted steel with a multiphase microstructure, containing ferrite, bainite, retained austenite, and some martensite. When deformed, the retained austenite transforms to martensite, which changes the phase balance in the alloy. Each microstructural constituent demonstrates a different behavior in the presence of hydrogen. The goal of this work is to understand the response of the hydrogen saturated multiphase structure to a mechanical load. Tensile tests on notched samples combined with in-situ electrochemical hydrogen charging were conducted. The test was interrupted at specific points, before the macroscopic failure of the material. Hydrogen induced crack initiation and propagation were examined by studying the microstructure at several intermediate elongations. Characteristic hydrogen induced cracks were only observed after reaching tensile strength and were located at the surface in a specific pattern. Finite element simulations indicated that the observed crack pattern coincides with the increased stress regions induced by the notch presence. This indicates that hydrogen induced crack formation is dominantly stress induced for this steel. Highlights: Hydrogen induced cracking in TRIP-assisted steel is evaluated. Tensile tests were conducted on notched hydrogen saturated samples. TRIP steels are very sensitive to hydrogen embrittlement. Hydrogen induced cracks were clearly present after reaching tensile strength. Hydrogen presence promotes stress-induced cracks in specific regions.