Investigating the long term effects of creep with chromate free primers

蠕变在生活的许多方面都有负面的含义。在涂覆金属线圈领域也是如此。蠕变描述了当腐蚀性物质在油漆金属界面的两半之间不知不觉地强行进入时发生的情况。这个过程从一块涂漆金属的切割边缘开始向内推进，其速度取决于附着力的强度，防腐武器的排列，当然还有推动化学物质前进的条件的强度。无铬底漆易发生边缘腐蚀。有些人认为，这种情况会在一段时间后减慢，而Galfan和HDG等基材上的涂层会在一段时间（5年）后“赶上”从切割边缘开始的蠕变程度，但在Beckers，我们没有看到这种情况。我们想了解镀锌层和其他两种基材边缘腐蚀的区别。为此，我们想应用电化学方法；扫描振动电极技术（SVET）对一小部分底漆和面漆应用于上述基材。项目目标：该项目的目的是描述使用电化学技术在Galvalume， Galfan和热浸镀锌钢上发生的切削边缘腐蚀。面板将涂上含铬酸盐底漆和不含铬酸盐底漆以及面漆。最多可尝试2种不同的防腐颜料。我们将研究任何差异，并解决影响切割边缘腐蚀速度的参数，以减缓边缘腐蚀的速度。将尝试电化学测试、盐雾和外部暴露之间的相关性。

Creep has negative conations in many walks of life. It is no different in the field of Coil Coated metal. Creep describes what happens when corrosive materials insidiously force their way between the two halves of the paint metal interface. The process starts from the cut edge of a piece of painted metal advancing inwards at a rate determined by the strength of adhesion, the anticorrosive weaponry lined up against it and of course the strength of the conditions pushing the chemicals forward.Chromate Free Primers for Galvalume suffer badly from edge corrosion. Some people believe that this slows down after a period of time and coatings on substrates such as Galfan and HDG 'catch up' on the extent of creep from the cut edge after a period of time (5 years) but at Beckers we have not seen this. We would like to understand the differences between edge corrosion on galvalume and the other 2 substrates. To this end we would like to apply the electrochemical methodology; Scanning Vibrating Electrode Technique (SVET) to a small selection of primers plus topcoats applied to the above mentioned substrates. Project aims:The aim of the project is to characterise the cut edge corrosion that takes place on Galvalume, Galfan and Hot Dip Galvanised Steel using electro-chemical techniques. The panels will be coated with chromate containing and chromate free primers plus topcoats. A maximum of 2 different anti-corrosive pigments will be tried. Any differences will be investigated and the parameters that impact on the speed of cut edge corrosion will be addressed in an effort to slow down the rate of edge corrosion. Correlations between electrochemical testing, Salt Spray and Exterior exposures will be attempted.