中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 29 No. 2 February 2019 |
（1. State Key Laboratory of Heavy Oil Processing, China University of Petroleum-Beijing, Beijing 102249, China;
2. Beijing Key Laboratory of Failure, Corrosion and Protection of Oil/Gas Facility Materials, China University of Petroleum-Beijing, Beijing 102249, China;
3. School of Mechanical and Chemical Engineering, The University of Western Australia, Perth, WA 6009, Australia）
Abstract:The corrosion behavior of electrodeposited Ni with normal and bimodal grain size distribution was investigated. The microstructure of samples was researched by SEM, EBSD, TEM and XRD. The corrosion behavior was studied by potentiodynamic tests and electrochemical impedance. Nanocrystalline Ni with (100) and (111) textures was prepared by an electrodeposition method. The Ni samples with different grain size distributions and twins were then obtained by heat treatment of nanocrystalline Ni at different temperatures. The effect of grain size on corrosion behavior of the sample depends on the ability of the environment to passivate. In the case where passive film forms on the sample surface, the corrosion resistance of the sample increases with decreasing grain size. Conversely, the corrosion resistance decreases with decreasing grain size when there is no passivation. The corrosion behavior of samples with bimodal grain size distribution obeys the rule of mixture.
Key words: corrosion behavior; electrodeposited Ni; bimodal grain; twin; grain size
