Corrodkote test

The CASS Test. In the copper-accelerated acetic acid salt spray (CASS) test (42), the positioning of the test surface is restricted to 15 2°, and the salt fog corrosivity is increased by increasing temperature and acidity, pH about 3.2, along with the addition of cupric chloride dihydrate. The CASS test is used extensively by the U.S. automobile industry for decorative nickel—chromium deposits, but is not common for other deposits or industries. Exposure cycle requirements are usually 22 hours, rarely more than 44 hours. Another corrosion test, now decreasing in use, for decorative nickel—chromium finishes is the Corrodkote test (43). This test utilizes a specific corrosive paste combined with a warm humidity cabinet test. Test cycles are usually 20 hours. 

It has been shown that chromium is virtually unattacked by the CASS test solution Nickel, on the other hand, is corroded at a substantial rate (about 0-072mm/y), the presence of the copper ions tending to maintain the nickel in an active state . Thus, in the CASS test (and in the Corrodkote test as well) accelerated galvanic corrosion of the nickel occurs at any discontinuities in the chromium layer. Good correlation between the results of the CASS test and the performance of plated parts in service has been reported . 

One cycle of the Corrodkote test will reliably reveal coatings that will not endure one winter s normal use in a typical city which uses salt to de-ice its streets. In contrast, several cycles of the Corrodkote test are generally required to fail coatings which will withstand one or more such winter s use. 

In this connection, there is some indication that while the Corrodkote test can be depended upon to reveal coatings of unsatisfactory durability, there has been some question as to its ability to distinguish between, or to predict the relative protective value or length of useful life of, different coating systems in the very good or excellent durability range. 

The Copper-Accelerated Salt Spray Test, ASTM B 368, commonly known as the CASS test, is typically used for testing copper-nickel chrome products. It was developed by the American Electroplaters Society as AES Research Project 15 [12], along with the Corrodkote Test (ASTM B 380) and incorporated into ASTM in 1965. 

The Corrodkote test, ASTM B 380 [74], was developed by the American Electroplaters Society to improve the performance of decorative plating used on automobiles. The original test protocol used actual Detroit city road slush consisting of dirt, road salt, and water [72]. The Corrodkote test uses a slurry consisting of kaolin, cupric nitrate (Cu(NOj)2 SH O), ferric chloride (FeCl, 6Hj), and ammonium chloride (NH,C1) in deionized water [74], The slurry is applied to the samples being tested. They are then placed in the humidity chamber maintained at 38 + 2°C and a relative humidity between 80 and 90 %, with no condensation on the parts. Twenty hours is considered one cycle [20]. Upon completion of the test, the specimens shall be cleaned with a mild abrasive and fresh running water. Additional... 

Although originally intended for evaluation of nickel-containing decorative electroplated coatings, the Corrod-kote test, ASTM B 380, has been used to qualify the performance of galvanized products for automotive applications. Apparently, the chloride ions introduced in this process provide a useful indication of automotive underbody performance for products such as tubing for containment of automotive fluids and other small components. The Corrodkote test applies a corrosive slurry to the... 

An accelerated corrosion test for some electrodeposits for anodic coatings on aluminum. Corrodkote test... 

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