クロメート処理亜鉛めっき鋼板の性能と皮膜構造に及ぼすりん酸およびコロイダルシリカの添加効果

概要

論文の詳細を見る
The performance and structure of chromate conversion coatings with phosphate or silica additives applied on the electro-galvanized steel have been investigated, and double roles of these additives in the film structure were proposed. It was found that phosphate reduces hexavalent chromium content, which is the possible reason for improvement of appearance and the adverse effect on corrosion resistance. While silica was found to form a bulky layer that can disperse yellowish hexavalent chromium and hold stable zinc corrosion product within the film, which can be related to the improvement of appearance and corrosion resistance. Phosphate forms a less-polor outer layer which repels paint, water and fingerprint. This is ascribable to the poor paint adhesion, relatively good wet adhesion and excellent fingermarking resistance of phosphate containing chromate. On the other hand, silica forms a polar outer layer which attracts paint, water and fingerprint. This is why the silica-containing chromate showed good paint adhesion as well as poor wet adhesion and a great amount of fingerprint adhered to its surface. The optimum film structure was designed based on these results.
社団法人日本鉄鋼協会の論文
1991-01-01