ASTM B117-2018 pdf free download

ASTM B117-2018 pdf free download.Standard Practice for Operating Salt Spray (Fog) Apparatus
1. Scope
1.1 This practice covers the apparatus, procedure, and conditions required to create and maintain the salt spray (fog) test environment. Suitable apparatus which may be used is described in Appendix X1. 1.2 This practice does not prescribe the type of test speci- men or exposure periods to be used for a specific product, nor the interpretation to be given to the results. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.4 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 appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Significance and Use
3.1 This practice provides a controlled corrosive environ- ment which has been utilized to produce relative corrosion resistance information for specimens of metals and coated metals exposed in a given test chamber. 3.2 Prediction of performance in natural environments has seldom been correlated with salt spray results when used as stand alone data. 3.2.1 Correlation and extrapolation of corrosion perfor- mance based on exposure to the test environment provided by this practice are not always predictable. 3.2.2 Correlation and extrapolation should be considered only in cases where appropriate corroborating long-term atmo- spheric exposures have been conducted. 3.3 The reproducibility of results in the salt spray exposure is highly dependent on the type of specimens tested and the evaluation criteria selected, as well as the control of the operating variables. In any testing program, sufficient repli- cates should be included to establish the variability of the results. Variability has been observed when similar specimens are tested in different fog chambers even though the testing conditions are nominally similar and within the ranges speci- fied in this practice.
4. Apparatus
4.1 The apparatus required for salt spray (fog) exposure consists of a fog chamber, a salt solution reservoir, a supply of suitably conditioned compressed air, one or more atomizing nozzles, specimen supports, provision for heating the chamber, and necessary means of control. The size and detailed con- struction of the apparatus are optional, provided the conditions obtained meet the requirements of this practice.4.2 Drops of solution which accumulate on the ceiling or cover of the chamber shall not be permitted to fall on the specimens being exposed. 4.3 Drops of solution which fall from the specimens shall not be returned to the solution reservoir for respraying. 4.4 Material of construction shall be such that it will not affect the corrosiveness of the fog. 4.5 All water used for this practice shall conform to Type IV water in Specification D1193 (except that for this practice limits for chlorides and sodium may be ignored). This does not apply to running tap water. All other water will be referred to as reagent grade. N OTE 1—Water used with a conductivity ≤1.0 µS/cm (or resistivity ≥1.0 MΩ·cm) may cause damage to some equipment due to the reactive nature of the water. In addition, it may cause issues with stabilizing pH measurements.
6. Preparation of Test Specimens
6.1 Specimens shall be suitably cleaned. The cleaning method shall be optional depending on the nature ofthe surface and the contaminants. Care shall be taken that specimens are not recontaminated after cleaning by excessive or careless handling. 6.2 Specimens for the evaluation ofpaints and other organic coatings shall be prepared in accordance with applicable specification(s) for the material(s) being exposed, or as agreed upon between the purchaser and the supplier. Otherwise, the test specimens shall consist of steel meeting the requirements of Practice D609 and shall be cleaned and prepared for coating in accordance with the applicable procedure of Practice D609.