A New Methodology for Accelerated Corrosion Testing
| Main Authors: | , |
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| Format: | Article |
| Language: | English Slovak |
| ISSN: | ISSN 0039-3630 |
| Online Access: | http://www.viks.sk/chk/studcon_4_03_263_268.doc |
| Abstract: | SUMARRIES. Accelerated corrosion tests have been used for almost 30 years to exclude corrosive materials from museum display and storage. The method reported by Green and Thickett in 1995 has been developed to allow the evaluation of three metals (silver, copper and lead) simultaneously in a single test. Comparison of a wide range of materials has shown that the differences in results introduced by this modification are less than the differences encountered with replicate tests using the same material employing the previous method. Problems encountered with corrosion in lead control tests have been investigated and the method has been modified to remove this effect. The cleaning method for the test vessels has been modified to exclude the hazardous chemical, chromic acid. CONCLUSION. During this research three independent aspects were examined and improved: tube cleaning, changes in lead control coupons, and developing a way to place the three coupons in one tube. In the cleaning process, a new procedure has been put in place. Chromic acid is now replaced by either a solution of dilute nitric acid or Decon 90 'Acid Rinse' detergent, both of which are significantly less dangerous to health and non-hazardous towards the environment. The unusual red corrosion on lead control coupons was explained by the contact of the coupon with the condensed water on the edges of the tube, condensation which was formed during the opening of the oven. To solve the corrosion problem on the control, the position of the tube in the standard test was changed from a leaning to a vertical position by using an aluminium tray. The utility of the accelerated corrosion test method has been significantly improved. The placing of all three metal coupons in a single tube not only saves time in preparing the tests but also improves the reproducibility of the positioning of the coupons, a factor not previously suspected in the amount of corrosion produced. The new test method gives a very high agreement with results from the previously published method. |
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| ISSN: | ISSN 0039-3630 |
