大氣腐蝕性分類與鹽霧試驗之模擬比對

The Salt Spray Test Compared with Atmospheric Corrosion Rating

為瞭解鹽水噴霧試驗模擬大氣腐蝕的相關性，本研究使用三種型式之鋅試片，於鹽水噴霧試驗機進行加速腐蝕試驗。配合稱重判定法，瞭解鋅金屬於鹽霧試驗中須進行多久之實驗時間，方可達到ISO標準規範定義之C1 ~ C5的腐蝕性等級，並將實驗結果歸納以量尺之型式呈現，方便使用對照。經鹽霧試驗結果顯示，進行試驗前須考慮試片形狀和置放方式等因素對腐蝕速率的影響。其中單面暴露之平板狀試片背面塗覆保護蠟，且試片擺放與垂直方向呈15°角，因此不會有腐蝕面積不一，以及氯鹽於表面凝結等問題，其腐蝕速率的估算值，較適合做為鋅金屬於ASTM B117試驗之試片。

In order to find the relationship between the salt spray test and atmospheric corrosion, this study used three forms of zinc specimens for salt spray test to determine the experiment period which will achieve the C1 ~ C5 corrosion rating defined by the ISO standard. The experimental results are presented as rulers. The salt spray test shows that the specimen shape and placement are the important factors on corrosion rate. The one-sided exposure specimen with a protective wax coating was placed with the vertical angle of 15 degree. Therefore, the one-sided exposure specimen should be more suitable in the experimental under ASTM B117 conditions.