Organic Composite Coated Steel Sheets Research Articles

複合サイクル腐食試験における有機複合被覆鋼板の耐食性機構

Organic composite coated steel sheets (OCC) show excellent corrosion resistance during cyclic corrosion tests (CCT). To clarify the mechanism behind this corrosion resistance, we studied changes in corrosion products and elements of plating, chromate, and organic resin layers of OCC with different organic resin layer weights. Larger amounts of corrosion products were detected on OCC with a smaller weight organic resin layer. Larger amounts of basic zinc chloride [ZnCl2·4Zn(OH)2] forming under the organic resin layer were detected by X-ray diffraction and electron probe microanalysis (EPMA) on OCC with a larger weight organic resin layer. Chromium remained in the chromate layer longer in OCC having the larger weight organic resin layer. The contribution of the corrosion products on the organic resin layer, the organic resin layer, the basic zinc chloride under the organic resin layer and the chromate layer to resistance was estimated by AC impedance measurements. That of the basic zinc chloride under the organic resin layer and the chromate layer was largest, followed by that of the organic resin layer. The excellent corrosion resistance of OCC therefore depends on the high barrier of the corrosion products on the organic resin layer and the ability to maintain the chromate layer and the basic zinc chloride under the organic resin layer in a corrosive environment.

複合サイクル腐食試験における有機複合被覆鋼板の腐食挙動

複合サイクル腐食試験における有機複合被覆鋼板の腐食挙動

高潤滑防錆鋼板の品質特性におよぼすベース有機樹脂および添加剤の影響

高潤滑防錆鋼板の品質特性におよぼすベース有機樹脂および添加剤の影響

有機複合被覆鋼板の電着塗装後の鮮映性におよぼす濡れ性の影響

有機複合被覆鋼板の電着塗装後の鮮映性におよぼす濡れ性の影響

高潤滑防錆鋼板の品質性能におよぼす潤滑有機皮膜組成の影響

高潤滑防錆鋼板の品質性能におよぼす潤滑有機皮膜組成の影響

耐もらい錆腐食性，電着塗装性に優れた自動車車体内外面用有機複合被覆鋼板の開発

耐もらい錆腐食性，電着塗装性に優れた自動車車体内外面用有機複合被覆鋼板の開発

機能性塗膜の新展開 塗装材料の塗膜‐プレコート材料の塗膜（２） 潤滑防錆鋼板

機能性塗膜の新展開 塗装材料の塗膜‐プレコート材料の塗膜（２） 潤滑防錆鋼板

有機複合被覆鋼板におけるシリカの防食機構

有機複合被覆鋼板におけるシリカの防食機構

高潤滑防錆鋼板

高潤滑防錆鋼板

耐低温チッピング性，塗装後鮮映性に優れた自動車車体外面用有機複合被覆鋼板の開発

耐低温チッピング性，塗装後鮮映性に優れた自動車車体外面用有機複合被覆鋼板の開発

Development of a new organic composite coated steel sheet with high corrosion resistance

To meet the recent requirement of high quality and performance of pure zinc electrogalvanized steel sheet, a study on a new organic composite coated steel sheet, called anti-fingerprinted steel sheet, has been carried out. The substrate was pure zinc electrogalvanized sheet with a metallic coating of 20 g m -2. Two different processes for inorganic (chromating) and organic (resin) coating were applied. One was a two coat/two bake type consisting of separate chromating and resin coating treatments which is now widely used. The other, newly developed for this study, was a one coat/one bake type with simultaneous treatments. The solution used for the one coat/one bake type was an water-based coating agent which was composed of both inorganic and organic components. The new organic composite coated sheet possesses superior corrosion resistance, and good paintability, formability and fingerprint resistance properties.

耐指紋処理鋼板の高温塗膜密着性におよぼす鋼板表面および試験環境の影響

Delamination and blistering behavior at the interface of the base plate and insulating layer were investigated during the hot press process for applying an insulating film to organic composite coated steel sheets with anti-fingerprint properties, which are used for printed curcuit boards. A chromate conversion film on an electrogalvanized coating was found to generate water by a dehydration reaction during the hot press process, which produced ZnO and H2 gas at the surface of the zinc layer and possibly induced delamination at the interface of the chromate film and zinc coating. Deterioration of secondary film adhesion after a humid cabinet test was attributed to rapid volumetric expansion due to the evaporation of water that had penetrated from the atmosphere through the insulating layer.

耐指紋処理鋼板の高温塗膜密着性におよぼす電気亜鉛めっき層中不純物の影響

Influence of the impurities in electrogalvanized coatings on film adhesion in organic composite coated steel sheets was investigated. A trace of Pb in the electrogalvanized coating layer caused a marked deterioration in film adhesion at high temperature, while the addition of Ni effectively improved it. A chromate conversion film on an electrogalvanized coating layer containing Pb was found to have larger amounts of the OH group than a film on a zinc coating containing Ni. It is suggested that the larger quantity of H2O generated from the electrogalvanized coating containing Pb by a dehydration reaction at elevated temperature progressively attacked the surface of the electrogalvanized coating layer, producing ZnO and H2 gas, which caused deterioration of film adhesion, leading to delamination and blisters during the hot pressprocess.

めっき鋼板のスポット溶接に関する研究（第１報） 薄膜有機複合めっき鋼板のスポット溶接における電極損耗について

Electrode life tests were conducted in resistance spot welding of organic composite coated steel sheets. The electrode lives obtained were almost equivalent to those of ordinal coated steels despite the fact that electrodes during the tests rapidly wore out. The long electrode lives can be attributed to a high contact resistance between the material coated with an organic film and an electrode. That is to say, although the high contact resistance leads to the rapid wear of electrodes caused by a frequent surface flash, this in turn effectively restricts a current path into a specific contact area between the material surface and the electrode and maintains a high current density sufficient to form a nugget even when the electrode wears out.

めっき鋼板のスポット溶接に関する研究（第２報） 薄膜有機複合めっき鋼板のスポット溶接性に及ぼす条件変動の影響

Investigation was conducted to evaluate potential factors in production lines which might influence resistance spot weldability of organic composite coated steel sheets. Those factors including electrode hardness, electrode downward speed (impact force), water flow rate, spot welding current and a relative location of an organic film to an electrode were selected and examined. The results showed that the sensitivity of this material to these factors is not very much different from that of conventional coated steels and thus this material can be used in established production lines without any special modifications.

水系樹脂による自動車用薄膜型有機複合めっき鋼板の開発

水系樹脂による自動車用薄膜型有機複合めっき鋼板の開発