金属和合金的腐蚀 人工大气中的腐蚀 在湿度循环和间歇性喷洒盐溶液的受控条件下进行加速腐蚀试验

This document specifies an atmospheric accelerated test procedure in two closely related variants that contain intermittent salt exposure combined with dynamic humidity patterns: variant A at constant dew point and variant B at constant temperature. These variants are used in assessing the corrosion resistance of metals in environments where there is a significant influence of chloride ions, mainly as sodium chloride from, for example, winter road de-icing salt. The results obtained do not permit far-reaching conclusions on the corrosion resistance of the tested metallic material under the whole range of environmental conditions in which it can be used. Nevertheless, the method provides information on the relative corrosion resistance of a material exposed to a salt-contaminated environment with varying humidity conditions. The two accelerated laboratory corrosion test variants are applicable to: — metals and their alloys (ferrous and non-ferrous); — metallic coatings; — chemical conversion coatings; — organic coating on metals; — a combination of materials and coatings that include galvanic interactions and/or crevice conditions. NOTE 1 If testing low-alloy stainless steels according to this document, especially austenitic grades, there is a risk of exaggerated pitting, which is not representative of most service environments. NOTE 2 This document is not suitable for testing of wax and oil-based rust protection agents, due to the constantly elevated temperature condition of the test. This document also specifies requirements on the test equipment and contains detailed procedures for quality control, including recommended instrumentation. This document does not specify the dimensions of the tests specimens, the exposure period to be used for a particular product, or the interpretation of the results. Such details are provided in the appropriate product specifications.