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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This page was last edited on 29 Octoberat The first climate cycle comprises a continuous indirect spray of neutral pH 6. Such tests are commonly referred to as modified salt spray tests.
In this connection it is well to point out that Practice B is not applicable to the study or testing of decorative chromium plate nickel-chromium on steel or on zinc-base die castings or of cadmium plate on steel.
Requirements are agreed between customer and manufacturer. For example, a typical electroplated zinc and yellow passivated steel part lasts 96 hours in salt spray test without white rust.
ASTM B – 07a Standard Practice for Operating Salt Spray (Fog) Apparatus
ASTM does not address this issue, but B117-007a does not recommend it and if it is to be done, advocates a thorough cleaning. Continuous operation implies that the chamber be closed and the spray operating continuously except for the short daily interruptions necessary to inspect, rearrange, or remove test specimens, to check and replenish the solution in the reservoir, and to make necessary recordings as described in Section How can I check whether my salt spray test chamber operates properly?
Table 2 shows the temperature, at different pressures, that are commonly used to offset the cooling effect of expansion to atmospheric pressure.
ISO standards by standard number.
ASTM-B STANDARD PRACTICE FOR OPERATING SALT SPRAY (FOG) APPARATUS_百度文库
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. It is b117-07s desirable to control the temperature of the surroundings of the salt spray chamber and to maintain it as stable as possible.
Test specimens are placed in an enclosed chamber, and exposed to a changing climate that comprises the following 3 part repeating cycle. There is a general historical consensus that larger chambers can provide a more homogeneous testing environment.
The salt spray test is one of the b1117-07a widespread and long established corrosion tests. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
This test can be used to test the relative resistance to corrosion paints on steelwhen exposed to a changing climate of dilute salt spray at ambient temperature, followed by air drying at and elevated temperature.
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. These standards describe the necessary information to carry out this test; testing parameters such as temperature, air pressure of the sprayed solution, preparation of the spraying solution, concentration, pHetc.
These acidified test solutions generally have a pH of 3. Cleaning of Tested Specimens Usually, the materials to be tested are metallic although stone, ceramics, and polymers may also be tested and finished with a surface coating which is intended to provide a degree of corrosion protection to the underlying metal.
Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. In the automotive industry requirements are specified under material specifications.
Slotted wooden strips are suitable for the support of? The most commonly used type is made of plastic. This is followed by 3. Sodium chloride containing anti-caking agents shall not be used because such agents may act as corrosion inhibitors.
Test specimens are placed in an enclosed chamber, and exposed to a changing climate that comprises the following 2 part repeating cycle. The fallout rate should be measured for 16 hours and it must range from 1. In either case, the exposure to salt spray may be salt water spray or synthetic sea water prepared in accordance with the requirements of the test standard.
NOTE 12—Recommended exposure periods are to be as agreed upon between the purchaser and the seller, but exposure periods of multiples of 24 h are suggested. The operating characteristics of a typical nozzle are given in Table X1. 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.
In any testing program, sufficient replicates should be included to establish the variability of the results. The principle application of the salt spray test is therefore enabling quick comparisons to be made between actual and expected corrosion resistance.
Salt Spray Test Chambers. Although there may be a weak correlation between the duration in salt spray test and the expected life of a coating in certain coatings such as hot dip galvanized steelthis test has gained worldwide popularity due to low cost and quick results. Although popular in certain industries, modified salt spray testing has in many cases been sstm by Cyclic corrosion testing CCT The type of environmental test chambers used for modified salt spray testing to ASTM G85 are generally similar to the chambers used for testing to ASTM Bbut will often have some additional features, such as an automatic climate cycling control system.
Variations to the salt spray test solutions depend upon the materials to be tested.