(1. 有研科技集團(tuán)有限公司 國(guó)家有色金屬及電子材料分析測(cè)試中心，北京 100088；
2. 國(guó)標(biāo)（北京）檢驗(yàn)認(rèn)證有限公司，北京 100088；
3. 北京有色金屬研究總院，北京 100088；
4. 中國(guó)船舶重工集團(tuán)有限公司第七二五研究所，青島 266237)
摘 要: 銅鎳合金管材腐蝕失效分析多集中于表面電化學(xué)腐蝕行為及鈍化膜結(jié)構(gòu)與耐腐蝕性能的關(guān)系。然而，銅鎳合金管材表面微觀組織結(jié)構(gòu)對(duì)其耐腐蝕性能的影響尚未澄清。本文采用掃描電鏡背散射電子衍射(SEM-EBSD)和原子力顯微鏡(AFM)對(duì)銅鎳合金管材表面晶粒取向和腐蝕形貌演化進(jìn)行了定位跟蹤觀察，以揭示不同取向晶粒的腐蝕行為和腐蝕形貌演化規(guī)律。結(jié)果表明：隨著銅鎳合金管材表面晶粒取向與〈111〉方向之間夾角的減小，晶粒表面腐蝕深度增加，腐蝕形貌由扇貝狀轉(zhuǎn)變?yōu)殡A梯狀或四面體凸起狀。這與晶粒表面能直接相關(guān)，符合臺(tái)階生長(zhǎng)模型(TLK)。
關(guān)鍵字: 銅鎳合金；定位跟蹤表征；晶粒取向；腐蝕形貌
（1. National Analysis and Testing Center for Nonferrous Metals and Electronic Materials, GRINM Group Co., Ltd., Beijing 100088, China;
2. Guobiao (Beijing) Testing & Certification Co., Ltd., Beijing 100088, China;
3. General Research Institute for Nonferrous Metals, Beijing 100088, China;
4. Luoyang Ship Material Research Institute, Qingdao 266237, China）
Abstract:The corrosion failure analysis of copper-nickel alloy pipes was mostly focused on the surface electrochemical corrosion behavior and the correlation between the structure of the passive film and the corrosion resistance. However, the effect of the surface microstructure of the copper-nickel alloy pipe on the corrosion resistance has not been clarified by now. In this paper, both the scanning electron microscopy with back scattered electron diffraction (SEM-EBSD) and atomic force microscopy (AFM) were utilized to characterize the orientation and corrosion morphology of the grains of the copper-nickel alloy pipe by indentation-tracking, so as to reveal the corrosion behavior and corrosion morphology evolution of the differently oriented grains. The results show that the corrosion depth of the grains increases and the corrosion morphology changes from scallop-like to step-like or tetrahedral convex shape as the angle between the grain orientation and the 〈111〉 direction decreases. It is directly related to the surface energy of the grains, which is in line with the terrace ledge kink (TLK) model.
Key words: copper-nickel alloy; indentation-tracking; grain orientation; corrosion morphology
