TY - JOUR

T1 - Impact of the nanostructuration on the corrosion resistance and hardness of irradiated 316 austenitic stainless steels

AU - Hug, E.

AU - Prasath Babu, R.

AU - Monnet, I.

AU - Etienne, A.

AU - Moisy, F.

AU - Pralong, V.

AU - Enikeev, N.

AU - Abramova, M.

AU - Sauvage, X.

AU - Radiguet, B.

PY - 2017/1/15

Y1 - 2017/1/15

N2 - The influence of grain size and irradiation defects on the mechanical behavior and the corrosion resistance of a 316 stainless steel have been investigated. Nanostructured samples were obtained by severe plastic deformation using high pressure torsion. Both coarse grain and nanostructured samples were irradiated with 10 MeV 56Fe5+ ions. Microstructures were characterized using transmission electron microscopy and atom probe tomography. Surface mechanical properties were evaluated thanks to hardness measurements and the corrosion resistance was studied in chloride environment. Nanostructuration by high pressure torsion followed by annealing leads to enrichment in chromium at grain boundaries. However, irradiation of nanostructured samples implies a chromium depletion of the same order than depicted in coarse grain specimens but without metallurgical damage like segregated dislocation loops or clusters. Potentiodynamic polarization tests highlight a definitive deterioration of the corrosion resistance of coarse grain steel with irradiation. Downsizing the grain to a few hundred of nanometers enhances the corrosion resistance of irradiated samples, despite the fact that the hardness of nanocrystalline austenitic steel is only weakly affected by irradiation. These new experimental results are discussed in the basis of couplings between mechanical and electrical properties of the passivated layer thanks to impedance spectroscopy measurements, hardness properties of the surfaces and local microstructure evolutions.

AB - The influence of grain size and irradiation defects on the mechanical behavior and the corrosion resistance of a 316 stainless steel have been investigated. Nanostructured samples were obtained by severe plastic deformation using high pressure torsion. Both coarse grain and nanostructured samples were irradiated with 10 MeV 56Fe5+ ions. Microstructures were characterized using transmission electron microscopy and atom probe tomography. Surface mechanical properties were evaluated thanks to hardness measurements and the corrosion resistance was studied in chloride environment. Nanostructuration by high pressure torsion followed by annealing leads to enrichment in chromium at grain boundaries. However, irradiation of nanostructured samples implies a chromium depletion of the same order than depicted in coarse grain specimens but without metallurgical damage like segregated dislocation loops or clusters. Potentiodynamic polarization tests highlight a definitive deterioration of the corrosion resistance of coarse grain steel with irradiation. Downsizing the grain to a few hundred of nanometers enhances the corrosion resistance of irradiated samples, despite the fact that the hardness of nanocrystalline austenitic steel is only weakly affected by irradiation. These new experimental results are discussed in the basis of couplings between mechanical and electrical properties of the passivated layer thanks to impedance spectroscopy measurements, hardness properties of the surfaces and local microstructure evolutions.

KW - Corrosion resistance

KW - High pressure torsion

KW - Irradiation resistance

KW - Nanostructured grains

KW - Stainless steel

UR - http://www.scopus.com/inward/record.url?scp=84988962495&partnerID=8YFLogxK

U2 - 10.1016/j.apsusc.2016.09.110

DO - 10.1016/j.apsusc.2016.09.110

M3 - Article

AN - SCOPUS:84988962495

VL - 392

SP - 1026

EP - 1035

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

ER -