Development of new electro-chemical methods for determination of tinplate quality

Five electrochemical test methods were evaluated for prediction of tinplate performance during this study. In addition, test packs were performed which provided some tinplate performance data. Three of the electrochemical methods gave inconclusive results in predicting tinplate performance. Two of these were anodic polarization in citric acid solutions involving different cell configurations. Another was anodic polarization of stress fractured samples in citric acid solution. One method, measuring the tin/steel alloy couple potential and current, gave results which appeared to predict tinplate performance, but the procedure was time consuming and the results were not easily reproducible. One method gave results which predicted tinplate performance and is recommended for use by the industry. This method measured tin dissolution rate and peak current as a function of time. The best performing tinplates gave lower peak currents and longer dissolution times. New electrochemical test cells were designed for four of the test electrochemical methods. One cell was designed to do five tinplate samples at once. A computerized test apparatus was developed for two of the test methods. This test apparatus greatly improved data handling and storage. A software program was configured to collect and evaluate data for the two computerized electrochemical methods