(1. 哈爾濱工業(yè)大學(xué) 應(yīng)用化學(xué)系, 哈爾濱 150001；
2. Faculty of Engineering, Kyoto University, Kyoto 606-8283, Japan)
摘 要: 脫去鍍錫板的自由錫層后， 在錫鐵合金層的表面目視發(fā)現(xiàn)了大量沿軋制方向伸展的白點(diǎn)， 并且合金層的耐蝕性隨著白點(diǎn)數(shù)量與覆蓋面積的增加而下降。采用掃描電鏡（SEM）觀察了合金層的形貌， 用能譜（EDS）分析了白點(diǎn)與非白點(diǎn)處的成分，結(jié)果發(fā)現(xiàn)： 白點(diǎn)處的合金層存在空洞， 且鐵的含量高于非白點(diǎn)處的含量。 將表面帶有大量白點(diǎn)的合金層進(jìn)行14d的濕熱實(shí)驗(yàn)后發(fā)現(xiàn)， 在白點(diǎn)的邊緣以及小白點(diǎn)處容易生銹， 采用原子力顯微鏡（AFM）觀察了銹點(diǎn)處的形貌， 并解釋了發(fā)生這一現(xiàn)象的原因。 通過實(shí)驗(yàn)室模擬和現(xiàn)場(chǎng)數(shù)據(jù)的分析， 找出了合金層表面白點(diǎn)產(chǎn)生的原因。
關(guān)鍵字: 白點(diǎn)； Sn-Fe合金層； SEM； AFM； 耐蝕性
（1. Department of Applied Chemistry, Harbin Institute of Technology,
Harbin 150001, China;
2. Faculty of Engineering, Kyoto University, Kyoto 606-8283, Japan）
Abstract:Massive white points outspreading along rolling direction on the surface of Sn-Fe alloy layer was discovered after removing tin coating of tinplates offered by some steel works. Corrosion resistance of alloy layer declines with the increase of amount of white points. Morphologies of alloy layer were observed by SEM, and composition of normal alloy layer and white points were analyzed by EDS. It is found that there are many cavities in the white point and the content of Fe in the white point is more than that in the normal alloy layer. In addition, hot-humidity testing was carried out for some plates whose surface has many white points. After 14 days, there are many rust points occurring at the edge of white points and in the small white points. Morphologies of rust points were observed by AFM. The reason why rust points generates at the edge of white points and in the small white points is discussed. Finally, the reason of generating white point on the surface of alloy layer is found out.
Key words: white point; Sn-Fe alloy layer; SEM; AFM; corrosion resistance
