藍化包紮鋼帶之耐蝕性質評估

Evaluation on the Corrosion Behavior of Tempered Package Steel Strips

包紮鋼帶用於鋼捲之包紮與固定，需使用具有良好抗拉強度之鋼帶，且此鋼帶需具備一定的耐蝕性質，以防止於露天儲放下發生嚴重的銹蝕現象。包紮鋼帶依欲包紮之鋼捲種類、用途，以及成本之考量，而使用不同的防蝕方式，其中最常見為藍化處理，其方式乃是將包紮鋼帶進行加熱，使其於表面生成一藍化層，之後再塗覆腊層。然而於實際使用中，發現到某公司生產之藍化包紮鋼帶，於短時間使用後即發生嚴重腐蝕現象。為了解包紮鋼帶易銹的原因，並比較不同製程參數所得之包紮鋼帶之耐蝕性質差異，本研究將利用電化學評估技術，分別就不同製程包紮鋼帶之底材、藍化層、腊層進行耐蝕性質評估，期能找出包紮鋼帶易銹之原因，並協助製程條件之改善。

Package steel strips are used for steel coil packing, which calls for a sufficient mechanical strength of the packing material, along with a moderate corrosion resistance. A common procedure used to enhance the corrosion resistance of this material is tempering treatment. Oxide layers with tempered colored are usually observed on the steel surface after a specific heat treatment. An extra layer of wax coating is then applied on the tempered steel for a better corrosion resistance. However, in one special incident, a package steel exhibited severe corrosion after only a short-term exposure. To explore the cause of severe and fast corrosion, we evaluated the corrosion behavior of the package steel with and without the oxide layer and the wax layer by electrochemical analyses. Furthermore, the impact of different treating procedures on the corrosion behavior of this steel was also investigated.