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961.
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963.
《Materials at High Temperatures》2013,30(3-4):287-292
AbstractStress corrosion cracking (SCC) is a damaging mode of alloys used in pressurised water reactors. Those damages led to the replacement of Alloy 600 (15% Cr) by alloy 690 (30% Cr) but the mechanism responsible for the SCC and the reason for the positive effect of chromium are not yet very well understood. In this paper, we studied the corrosion of synthetic alloys – with controlled chromium content varying from 5 to 30 wt%. Characterisation was done using SEM and TEM observations together with chemical analysis and mapping using EDX, EFTEM and SIMS. The outer oxide scale is composed of crystallites, beneath it the presence of a continuous chromium oxide is accompanied with a Cr depleted zone for alloys that contain more than 10% Cr. The penetration of oxygen over very large distances (several microns) on triple junctions is demonstrated, as well as the role of plastic deformation that modifies strongly the overall structure of the oxide scale. 相似文献
964.
Subhendu Bhandari 《国际聚合物材料杂志》2016,65(11):543-549
Polyaniline (PAni) was electrochemically synthesized from aniline sulfate (AS) in the presence and in absence of H2SO4 using Cu counter electrode. No significant corrosion of the Cu electrode was found while synthesizing from AS in presence of H2SO4, whereas relatively higher corrosion of Cu as well as contamination of synthesized PAni with corroded Cu were observed for the synthesis from aniline in presence of H2SO4 or from AS in the absence of H2SO4. Corrosion-free synthesis yields PAni free from contamination of Cu and exhibits smaller particle size and superior electrical and supercapacitive behavior compared to the process exhibiting corrosion of counter electrode. 相似文献
965.
This paper presents a new approach to assess time-dependent corrosion fatigue damage of welded joint considering the coupling effect between mechanical factor and corrosion factor. The high stress region around weld will accelerate corrosion and be more likely to induce nonuniform corrosion of welded joint. And the effect of loading on corrosion behavior of the steel in NaCl solution was investigated. The synergistic effect between applied elastic stress and chemical attack on Q235 steel was evaluated by electrochemical experiments. A side longitudinal of ship structure is selected as a case study. Time-dependent stress concentration factor of welded joint as a function of corrosion deterioration was analyzed, and the iterative process of stress and corrosion degeneration of plate thickness was used to simulate coupling effect basing on the results of experiment. The hot spot stress approach was adopted to calculate the fatigue damage. It is revealed that the nonuniform corrosion could influence fatigue damage of welded joint, and that impact will be more and more significant with the growth of corrosion year. 相似文献
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968.
Kazushige Ishida Yoichi Wada Masahiko Tachibana Nobuyuki Ota Motohiro Aizawa 《Journal of Nuclear Science and Technology》2013,50(11):1071-1082
The effects of water chemistry distribution on the potential of a reference electrode and of the potential distribution on the measured potential should be known qualitatively to obtain accurate electrochemical corrosion potential (ECP) data in BWRs. First, the effects of oxygen on a platinum reference electrode were studied in 553 K pure water containing dissolved hydrogen (DH) concentration of 26–105 μg kg?1 (ppb). The platinum electrode worked in the same way as the theoretical hydrogen electrode under the condition that the molar ratio of DH to dissolved oxygen (DO) was more than 10 and that DO was less than 100 ppb. Second, the effects of potential distribution on the measured potential were studied by using the ECP measurement part without platinum deposition on the surfaces connected to another ECP measurement part with platinum deposition on the surfaces in 553 K pure water containing 100–130 ppb of DH or 100–130 ppb of DH plus 400 ppb of hydrogen peroxide. Measured potentials for each ECP measurement part were in good agreement with literature data for each surface condition. The lead wire connecting point did not affect the measured potential. Potential should be measured at the nearest point from the reference electrode in which case it will be not affected by either the potential distribution or the connection point of the lead wire in pure water. 相似文献
969.