Long-term corrosion evolution associated with the structural heterogeneities of an Fe-based amorphous coating in H3BO3 solution at various temperatures
Long-term corrosion evolution associated with the structural heterogeneities of an Fe-based amorphous coating in H3BO3 solution at various temperatures
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DOI：
10.1016/j.jmst.2022.08.039
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发表时间：
2022-10
期刊：
影响因子：
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通讯作者：
D.B. Wang;J. Wu;J. Cui;Q. Wang;T.R. Li;W. Emori;S.D. Zhang;J.Q. Wang
中科院分区：
文献类型：
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作者：
D.B. Wang;J. Wu;J. Cui;Q. Wang;T.R. Li;W. Emori;S.D. Zhang;J.Q. Wang
了解中子吸收材料在h3bo3溶液中的长期腐蚀行为对材料在乏燃料储存中的应用至关重要。本文系统研究了不同温度下铁基非晶涂层（AMC）在h3bo3溶液中180d的长期腐蚀演变与结构非均质性的关系。结果表明，涂层的腐蚀可分为三个不同的阶段。最初，由于钝化膜的增厚和成分的演变，耐蚀性提高。第二阶段腐蚀速率基本保持不变，这与钝化膜的稳定状态有关。最后，由于局部腐蚀的萌生和渗透，涂层的耐蚀性逐渐降低。有趣的是，局部腐蚀发生在涂层深层孔隙中相对贫cr的非晶基体上。这可能是长期浸没过程中深孔cr耗竭和闭塞效应协同作用的结果。随着温度的升高，孔隙中H+的积累增强了局部腐蚀，迅速达到钝化膜击穿的临界条件。本研究为fe基AMCs在h3bo3溶液中的长期腐蚀机制提供了新的见解，并为设计用于乏燃料储存的新型耐腐蚀中子吸收涂层提供了有意义的贡献。
Understanding the long-term corrosion behavior of neutron absorber materials in H3BO3solution is crucial for the materials applications in spent fuel storage. In this paper, long-term corrosion evolution for 180 d in relation to the structural heterogeneities of an Fe-based amorphous coating (AMC) in H3BO3solution at various temperatures was systematically investigated. Results indicate that the coating corrosion could be divided into three distinct stages. Initially, the corrosion resistance increased owing to the thickening and composition evolution of the passive films. Subsequently, the corrosion rate was kept almost constant in the second stage, which connected with the steady state of the passive film. Finally, the corrosion resistance of coating reduced gradually owing to the initiation and penetration of localized corrosion. Interestingly, it was revealed that the localized corrosion was initiated at the relatively Cr-depleted amorphous matrix in the deep pores of the coating. This could be attributed to the synergy of Cr-depletion and occlusive effect in the deep pores during long-term immersion. With the elevation of temperature, the localized corrosion was enhanced due to the accumulation of the H+in the pores to swiftly reach the critical conditions for passive film breakdown. This work provides insights into the long-term corrosion mechanism of Fe-based AMCs in H3BO3solution and offers meaningful contributions to the design of new corrosion resistant neutron absorbing coatings for spent fuel storage applications.