Corrosion Analyses
In the area of environmental simulation, a test process exists with which industrial materials are tested for corrosion resistance in atmospheres containing salt – the salt mist test, also called salt spray test.
The usual standards according to which the salt mist test is implemented are DIN 50021 SS (standard), DIN 53167, DIN EN 60068-2-52 (cylindrical salt mist), DIN EN ISO 9227, and DIN EN 60068-2-11.
The test object is stored in a special test chamber over a pre-specified test duration and is exposed to a misty atmosphere containing salt. This simulates in condensed form the exposure of the test object to salt solutions (road traffic) during its service life. Standard run times for salt spray tests are approximately 96 to 240 hours. Test parameters are well-defined.
A sodium chloride solution is normally used with a concentration of approximately 5% and a pH value of 6.5-7.2, and a temperature of 35°C. In order to ascertain how susceptible the material or corrosion protection layer of the material is to the salt solution, the test is interrupted at periods of approximately 24 hours to analyze the test object for areas of corrosion.
The standard on which the test is based in the end determines whether the material is able to fulfill the requisite criteria. Salt mist tests are especially useful for products used on high seas or in the immediate vicinity to an ocean, as salt loads are largest in such surroundings. Salt mist tests are also used in the automotive sector, and are now part of standard testing procedures. Further test methods exist in addition to salt mist tests where materials are sprayed with other media or are subjected to condensation.
Salt mist and condensation water chamber
Salt mist | Condensation water | Humidifier | |
|---|---|---|---|
| Max. temperature | +55°C | +45°C | +75°C |
| Min. temperature | 5K > TU | 5K > TU | 5K > TU |
| TU=+23°C |
SO2 test
Corrosive gas tests are used for the corrosion testing of metals and for determining the speed of aging with plastics and glass. Another important test area is the testing of coatings and casings for tightness.
SO2 (industrial atmosphere) in accordance with DIN EN ISO 6988 / 50018
We have a modular corrosive gas climate simulation system able to implement many standard-compliant test procedures.
Salt mist in accordance with DIN 50 021
Process | |
|---|---|
| 1. Phase (8 h) | Moistening of lamps, (40°C, 100 % rel. humidity) Addition of SO2 gas (sulfuric acid produced on test objects) |
| 2. Phase (16 h) | Adaptation to room temperature (18-28°C, max. 75 % rel. humidity) |
Duration | |
|---|---|
| 1 cycle | 24 h |
| 5 cycles à 24h | 120 h |
Salt mist in accordance with DIN 50 021
Parameters | |
|---|---|
| Temperature in chamber | 35°C |
| NaCl concentration | 50 g/l = 5 % solution |
| Duration max. | 240 h |
Salt mist and condensation water chamber
Corrosive gas tests
in accordance with DIN EN 60068-2-43 Kd | |
|---|---|
| Width | circa 630 mm |
| Depth | circa 630 mm |
| Height | circa 670 mm |
| Capacity | circa 270 l |
| Field for climate tests with corrosive test equipment | +15 °C to +60 °C |
| Moisture range | 10 % r. F. to 93 % r. F. |
| Water dewpoint | +10 °C to +38 °C |
| Special climate point | +25 °C/95 % r. F. |