Abstract Changes in legislation have led to Cr (VI) being removed from manufacturing processes and this has an impact on the production of chromium coated packaging steel products. Novel substrates produced using Cr(III) in the electroplating process are being developed, but have yet to reach the mature functionality of the Cr(VI) substrates. As part of the development of a Cr(III) plated steel substrate the presence of citric acid during the retort process was found to be beneficial to adhesion at the lacquer / substrate interface. At the correct concentration it could negate the presence of the usually corrosion inducing sodium chloride. The use of citric acid as a pre-treatment was subsequently investigated and through optimization it was possible to increase the adhesion performance of the substrate. The operating window of treatment was a function of solution temperature and time with best performance being achieved in 5 mins at 95°C. Over exposure to citric acid had a detrimental effect on substrate / lacquer adhesion. The primary mechanisms of citric acid treatment were identified as iron dissolution and chrome oxidation which enhanced the number of substrate surface bonding sites.

中文翻译：

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通过柠檬酸处理对 Cr(III) 封装基材进行表面改性以增强附着力

摘要 立法的变化导致 Cr (VI) 从制造过程中被去除，这对镀铬包装钢产品的生产产生了影响。在电镀过程中使用 Cr(III) 生产的新型基材正在开发中，但尚未达到 Cr(VI) 基材的成熟功能。作为镀 Cr(III) 钢基材开发的一部分，在蒸馏过程中柠檬酸的存在被发现有利于漆/基材界面的附着力。在正确的浓度下，它可以消除通常会引起腐蚀的氯化钠的存在。随后研究了使用柠檬酸作为预处理，并通过优化可以提高基材的粘附性能。处理的操作窗口是溶液温度和时间的函数，在 95°C 下 5 分钟内达到最佳性能。过度暴露于柠檬酸会对基材/漆的附着力产生不利影响。柠檬酸处理的主要机制被确定为铁溶解和铬氧化，这增加了基材表面结合位点的数量。