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Warsaw University of Technology, Faculty of Materials Science and Engineering, Wołoska 141, 02-507 Warsaw, Poland. HYDROGEN DEGRADATION OF EXPLOSION CLADDED STEEL S. Krystyna Lublińska, Andrzej Szummer, Krzysztof Jan Szpila , Krzysztof Jan Kurzydłowski . klublin@meil.pw.edu.pl.
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Warsaw University of Technology,Faculty of Materials Science and Engineering,Wołoska 141, 02-507 Warsaw, Poland HYDROGEN DEGRADATIONOF EXPLOSION CLADDED STEELS Krystyna Lublińska, Andrzej Szummer, Krzysztof Jan Szpila, Krzysztof Jan Kurzydłowski klublin@meil.pw.edu.pl 8th May, Lisse
OUTLINE Introduction Research goals Investigated materials and researchtechniques Results Conclusions
BASIC INFORMATION Faculty of Materials Science and Engineering Warsaw University of Technology • independent faculty since 1991 • institutesince 1920 • TheFacultyiscurrentlycarrying out 23 joint researchprojectswith 19 foreign partners, whichinclude: • Waterloo University, Canada • BeijingPolytechnicUniversity, China • Institute of Physics of the Czech Academy of Sciences • UniversiteParis-Sud XI, France • Ecole des Mines de St. Etienne, France • Dortmund University, Germany • Max Planck Institut fur Metallforshungin Stuttgart, Germany • HungarianAcademy of Sciences, Hungary • Moscow State University, Russia • Institutes of Physics of theSlovakianAcademy of Sciences • UlsanUniversity, South Korea • UniversidadComplutense de Madrid, Spain • Oxford University, UK • Department of Engineering Materials, University of Sheffield, UK • CornellUniversity, USA Warsaw
structuralsteels clad plates hydrogen degradation (hydrogencorrosion) disbonding differences in: diffusion and solutibility of hydrogen temperature crystalographic structure microstructural changes reduction of useful properties R. Paschold, L. Karlsson, M. F. Gittos, „Disbonding of Austenitic Weld Overlays in Hydroprocessing Applications”, Svetsaren no. 1 – 2007, 10-15
FCC vs. BCC austenite ferrite hydrogen diffusion coefficient 10-15 m2/s low high 8,46·10-11 m2/s high hydrogen solutibility low LOCAL SUPERSATURATION OF HYDROGEN DISBONDING www-ee.ccny.cuny.edu
RESEARCH GOALS Investigation of influence of cathodic hydrogen on microstructure of the interface of clad plate (304L/13CrMo4-5) Determination of influence of heat treatment on hydrogen corrosion of the interface of clad plate (304L/13CrMo4-5)
INVESTIGATED MATERIALS Chemical composition [wt %] 3 mm of austenitic stainless steel (304L) 304L 15 mm of low alloy steel (13CrMo4-5) 13CrMo4-5 Claded plates were manufactured during intership at ZTM „EXPLOMET” in Opole, Poland
ANNEALING • 1223K (950°C) • 1 hour • argon atmosphere • cooled with furnace RESEARCH TECHNIQUES • light microscopy • scanning electron microscopy • shear tests (according to ASTM SA-264)
EXPERIMENTAL - HYDROGEN CHARGING • Hydrogenchargingparameters: • 0,5M H2SO4 solution, with 1mg/dm3 As2O3 addition (hydrogenentrypromoter), • ambienttemperature, • currentdensity: 50mA/cm2 • time: 18 hours _ + _ + platinium anode specimen power supply (i – const.) 304L H2SO4 + As2O3 13CrMo4-5
EFFECT OF HYDROGEN CHARGING hydrogen induced blistersin 13CrMo4-5 steel hydrogen induced blisters with microcracksin 13CrMo4-5 steel
a) 304 b) c) EFFECT OF HYDROGEN CHARGING XRD patterns of 304 steel a) 20h after hydrogen charging, 18 h, 0.1 A/cm2 b) directly after hydrogen charging, 18 h, 0.1 A/cm2 c) withouthydrogen charging A. Szummer ,”Hydrogen Degradation of Ferrous Alloys” USA (1985), 512
EFFECT OF HYDROGEN CHARGING hydrogen induced microcracks (intergranular and transgranular) in 304L steel
EFFECT OF HYDROGEN CHARGING 13CrMo4-5 13CrMo4-5 304L 304L 304L 13CrMo4-5 13CrMo4-5 304L 304L unannealed, hydrogen charged
EFFECT OF ANNEALING 304L 13CrMo4-5 13CrMo4-5 304L unannealed annealed 6/xx
EFFECT OF ANNEALING 304L 13CrMo4-5 13CrMo4-5 304L unannealed annealed
EFFECT OF ANNEALING 304L 304L 13CrMo4-5 13CrMo4-5 unannealed annealed 6/xx
EFFECT OF ANNEALING 304L 304L 13CrMo4-5 13CrMo4-5 unannealed annealed
EFFECT OF ANNEALING AND HYDROGEN CHARGING 304L 304L 304L 13CrMo4-5 13CrMo4-5 304L 13CrMo4-5 13CrMo4-5 unannealed annealed
SHEAR TESTS RESULTS Shear strenght loss: Z = (RtN – RtH) ∙ 100%/ RtN, where: RtN – shear strenght of uncharged sample, RtH – shear strenght of hydrogen charged sample.
SHEAR TESTS RESULTS uncharged, unannealed hydrogen charged, unannealed uncharged, annealed hydrogen charged, annealed 16/xx
CONCLUSIONS Hydrogen causes significant changes in microstructure in the flyer layer (surface microcracks and blisters) and base layer (blisters) of the investigated clad plates. Strong detoriation of microstructure, caused by explosion cladding, increases susceptibility to increased hydrogen embritllement in the thin layer of austenitic stainless steels along the interface. Annealing allows to avoid formation of brittle area along the interface, produce more homogeneous material and reduces the negative effect of hydrogen. Annealing, which removes the high deformation of grains, allows to fabricate a clad plate, which may work in enviroment with hydrogen presence.
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