Improving resistance of austenitic stainless steel to irradiation damage

It is believed that the addition of oversized solute atoms disturbs the process of recombination, agglomeration, and migration of point defects during irradiation process and thereby alters radiation damage, including radiation induced segregation. In this study, austenitic stainless steel (SS) 316 samples with different Ce content (0.00, 0.01, 0.04 and 0.09 wt% Ce) were irradiated using 4.8 MeV protons at 300°C to the total fluence of 9.724×1017 p/cm2. Irradiated samples were characterized using double-loop electrochemical potentiokinetic reactivation (DL-EPR) technique for the extent of RIS due to proton irradiation. It was found that the sample with 0.04 wt% Ce content showed the lowest EPR value, as measured by DL-EPR. It was also noticed that the slip lines were get preferentially attacked vis-à-vis grain boundaries. SS 316 Ce 0.09 wt% sample did not have any slip-lines and attack during the DL-EPR was confined to grain boundaries and few pitlike structures were noticed during AFM examinations

Impact Energy Modeling

Provides all origin files used in simulation of impact energy using sigmoidal models.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Effect of residual strain on radiation induced segregation in SS 304

The effect of residual strain on radiation-induced segregation in proton-irradiated type 304 stainless steel was investigated using electrochemical potentiokinetic reactivation (EPR) test followed by atomic force microscopic examination. The specimens were irradiated to 0.43 and 0.86 dpa. Microstructural observation after EPR of irradiated specimens showed negligible attack on grain boundaries. Attacked linear features were noticed after EPR testing of irradiated specimens while such features were not observed for un-irradiated as-received or irradiated solution-annealed specimen. The presence of linear features after EPR testing of irradiated specimens was attributed to decoration of strain-regions within the matrix by point-defects generated due to irradiation. (c) 2011 Elsevier Ltd. All rights reserved

Radiation-induced segregation in desensitized type 304 austenitic stainless steel

Radiation-induced segregation (RIS) in desensitized type 304 stainless steel (SS) was investigated using a combination of electrochemical potentiokinetic reactivation (EPR) test and atomic force microscopy (AFM). Desensitized type 304 SS was irradiated to 0.43 dpa (displacement per atom) using 4.8 MeV protons at 300 degrees C. The maximum attack in the EPR test for the irradiated desensitized SS was measured at a depth of 70 mu m from the surface. Grain boundaries and twin boundaries got attacked and pit-like features within the grains were observed after the EPR test at the depth of 70 mu m. The depth of attack, as measured by AFM, was higher at grain boundaries and pit-like features as compared to twin boundaries. It has been shown that the chromium depletion due to RIS takes place at the carbide-matrix as well as at the carbide-carbide interfaces at grain boundaries. The width of attack at grain boundaries after the EPR test of the irradiated desensitized specimen appeared larger due to the dislodgement of carbides at grain boundaries. (C) 2011 Elsevier B.V. All rights reserved

The role of niobium carbide in radiation induced segregation behaviour of type 347 austenitic stainless steel

The effect of niobium carbide precipitates on radiation induced segregation (RIS) behaviour in type 347 stainless steel was investigated. The material in the as-received condition was irradiated using double-loop 4.8 MeV protons at 300 degrees C for 0.43 dpa (displacement per atom). The RIS in the proton irradiated specimen was characterized using double-loop electrochemical potentiokinetic reactivation (DL-EPR) test followed by atomic force microscopic examination. The nature of variation of DL-EPR values with the depth matched with the variation of the calculated irradiation damage (dpa) with the depth. The attack on grain boundaries during EPR tests was negligible indicating absence of chromium depletion zones. The interface between niobium carbide and the matrix acts as a sink for point defects generated during irradiation and this had reduced point defect flux toward grain boundaries. The attack was noticed at a few large cluster of niobium carbide after the DL-EPR test at the depth of maximum attack for the irradiated specimen. Pit-like features were not observed within the matrix indicating the absence of chromium depletion regions within the matrix. (C) 2011 Elsevier B.V. All rights reserved

Radiation-induced segregation in austenitic stainless steel type 304: Effect of high fraction of twin boundaries

The effect of high fraction of twin boundaries on radiation-induced segregation (RIS) in type 304 stainless steel (SS) was investigated using 4.8 MeV proton beam at 300 degrees C. Type 304 SS samples were irradiated to 0.86 and 1.00 displacement per atom (dpa) and characterization of RIS was done using Electrochemical Potentiokinetic Reactivation (EPR) tests at different iepth from the surface. Localized attack on different microstructural features, grain and twin boundaries and in-grain pit-like features, was further evaluated by atomic force microscopy. The results clearly indicated that attack was mostly confined to twin boundaries, implying that the twin boundaries acted as a preferred defect sink. (C) 2011 Elsevier B.V. All rights reserved

Electrochemical Evaluation of Radiation-Induced Segregation in Austenitic Stainless Steels with Oversize Solute Addition

Effect of different levels of oversize element, cerium, on radiation-induced segregation (RIS) in type 316 stainless steel was investigated. The effect of prior cold-work on RIS was also investigated. Samples with 0.00, 0.01, and 0.04 wt.% cerium were irradiated to 0.70 dpa using 4.8 MeV protons at 300 A degrees C. Characterization of proton-irradiated specimens was carried out using electrochemical potentiokinetic reactivation (EPR) test followed by atomic force microscopic examination. The specimen with prior cold-work (without cerium addition) showed the lowest EPR values indicating the lowest chromium depletion in this material. The specimen with 0.04 wt.% cerium showed the lower EPR value as compared to the specimen with 0.01 wt.% Ce. The irradiated specimen with prior cold-work showed linear features after the EPR tests and such features were attributed to decoration of dislocations, generated due to prior cold-work, by point defects produced during irradiation. The resistance to RIS offered by cold-work (linear features) has been more effective as compared to that by the addition of oversize solute addition