The salt spray (or salt fog) test is a standardized and popular corrosion test method, used to ASTM B was the first internationally recognized salt spray standard, originally published in Other important relevant standards are. Designation: B – 07a Standard Practice for Operating Salt Spray (Fog) Apparatus1 This standard is issued under the?xed designation B. ASTM B Testing, also known as a Standard Practice for Operating Salt ASTM B Testing requires controls over many operational parameters such as: .
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The salt spray test has little application qstm predicting how materials or surface coatings will resist corrosion in the real-world, because it does not create, replicate or accelerate real-world corrosive conditions.
This test can be used to test the relative resistance to corrosion of aluminium alloys when exposed to a changing climate of acetic acid salt spray, followed by air drying, followed by high humidity, all at an elevated temperature.
Salt spray test – Wikipedia
Results are represented generally as testing hours in NSS without appearance of corrosion products e. Suspension b117-7a glass hooks or waxed string may be used as long as the speci? This test can be used to test the relative resistance to corrosion of coated or uncoated aluminium alloys and other metals, when exposed to a changing climate of acidified synthetic seawater spray, followed by a high humidity, both at an elevated temperature.
ASTM G85 is an example of a test standard which contains several modified salt spray tests which are variations to the basic salt spray test. Please log in, in order to get access to prices, ordering and inquiry functions. b1117-07a
The most appropriate test cycle and spray solutions are to be agreed between parties. Careful attention should be given to the chemical content of the salt.
NOTE 1—Should it be desirable to cut test specimens from parts or from preplated, painted, or otherwise coated steel sheet, the cut edges shall be protected by coating them with paint, wax, tape, or other b1117-07a media so that the development of a galvanic effect between such edges and the adjacent plated or otherwise coated metal surfaces, is prevented.
For this reason the salt spray test is most often deployed in a quality audit role, where, for example, it can be used to check the effectiveness of a production process, such as the surface coating of a metallic part. Usually, the materials to be tested are metallic although stone, ceramics, and polymers may also be tested and finished with a surface coating b117-07x is intended to provide a degree of corrosion protection to the underlying metal.
Test specimens are placed in an enclosed chamber, and exposed to 1 of 2 possible changing climate cycles.
All other water will be referred to as reagent grade. NOTE 10—A solution having a speci? A solution that requires between 3. The controls allow for the normalization of test conditions during repeated running of the test and will also allow comparisons of test results from different repeats of the same test. The size and detailed construction of the apparatus are optional, provided the conditions obtained meet the requirements of this practice. However, these testing standards neither provide information of testing periods for the coatings to be evaluated, nor the appearance of corrosion products in form of salts.
Hot-dip galvanizing produces zinc carbonates when exposed to a natural environment, thus protecting the coating metal and reducing the corrosion rate. Cleaning of Tested Specimens It is preferred that control panels be provided that bracket the expected test specimen performance.
Most Salt Spray Chambers today are being used NOT to predict the corrosion resistance of a coating, but to maintain coating processes such as pre-treatment and painting, electroplating, galvanizing, and the like, on a comparative basis.
Although the majority of salt spray tests are continuous, i. A number in parentheses indicates the year of last reapproval. The chamber has the following features: The b17-07a of making the scratch shall be as de?
This produces a corrosive environment of dense salt water fog also referred to as a mist or spray in the chamber, so that test samples exposed to this environment are subjected to severely corrosive conditions. Conditions in the Salt Spray Chamber Current edition approved Dec. This test is also referred to as an ASS test.
Once a year the corrosivity of the salt spray test chamber has to be checked. Accessories for Corrosion Testing. In any testing program, sufficient replicates should be included to b11707a the variability of the results.
Vent piping should be of sufficient size so that a astn of back pressure exists and should be installed so that no solution is trapped.
The distribution of the salt fog inside the test chamber has to be regularly checked. Other test solutions have other astmm added including acetic acid often abbreviated to ASS and acetic acid with copper chloride often abbreviated to CASS each one chosen for the evaluation of decorative coatings, such as electroplated copper-nickel-chromium, electroplated copper-nickel or anodized aluminum.