【国外标准】 Standard Test Method for Chloride Resistance Test for Chromium Electroplated Parts (Russian Mud Test)

3.1 This test replicates in the laboratory the corrosive actions of a film containing hygroscopic chlorides and solid material (mud) on electroplated chromium. The test’s reactive media, the test slurry, was developed to simulate the film found on electroplated chromium deposits during a winter in Russia, thus the common name for the test, Russian Mud Test.3.2 This test is used for specification acceptance, simulated service evaluation, manufacturing control, and research and development. It was developed specifically for use on components with electrodeposited chromium coatings exposed to hygroscopic chlorides. Test and production specimens may be used. Use of a standardized test could help in developing improved quality of chromium electrodeposited components and lead to the development of improved electroplated chromium systems.3.3 This test simulates the amount of electrodeposited decorative and functional chromium deposit lost when exposed to the combination of “mud/solid material” and hygroscopic chlorides, most commonly calcium chloride. The metric is the loss of only the chromium and adjacent nickel layer. Other tests used with nickel/chromium electroplated components, such as CASS (Test Method B368), simulate the resistance of the part to basis metal corrosion involving all of the component’s deposits and substrate.1.1 This standard details a laboratory method to accelerate the effects of exposure to hygroscopic corrosive chloride compounds on electroplated chromium components. It is applicable to any substrate and coating system that utilizes electroplated chromium as the final metallic coating.1.2 Field experience has shown that hygroscopic chlorides are significantly more aggressive than sodium chloride toward chromium electroplated deposits. The most common of which is calcium chloride.1.3 The standard does not specify exposure periods to be used for a specific product nor the interpretation to be given to the results. The suitability of this test and correlation of results with service experience should be determined before it is specified for coating systems.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.