Immersion testing test duration

The salt water immersion test (SWI) and the standard salt spray (fog) test (SS) were conducted for both ISPCs and control baking enamels applied on bare CRS, iron phosphated B-1000, and BD+P60 panels. The painted coupons of about 1.0 mil dry film thickness cured at 163 C for 15 minutes were X-cut through the film to the substrate and then either immersed in a 3% NaCI solution (SWI test) or subjected to a continuous salt-solution spray in a test chamber (SS test). After a specified duration of testing, the specimens were removed from the salt solution, and the coated surface was immediately dried. A DUCK brand tape (Manco, Inc., Westlake, OH) was applied over the X-cut and then removed, and the protective performance was... 

Section HI covers Types of Tests (H. Hack, Section Editor) includirrg laboratory-accelerated tests, field tests, and service tests. The chapters in this section provide basic principles, describe test techniques and specific considerations such as specimen preparation, test duration and acceleration factors, and cite pertinent standards. Chapters included under laboratory tests are electrochemical, cabinet, immersion, high temperature, and high pressure. Field Tests chapters include atmospheric exposure, seawater, fresh water, and soil. Under service tests are industrial applications and high temperature environments. 

The type of laboratory immersion test to be used will be determined mostly by the environmental conditions that are to be simulated. For example, if the equipment is immersed in service, then the test specimens should be immersed in the laboratory test if the exposure is alternating immersion and atmospheric exposure, then a cyclic exposure test to wet/dry conditions should be used. Another determining factor is the duration of exposure for arriving at the desired results, which is associated with the degree of acceleration that will be required of the test method. 

The test is carried out by completely immersing the test enclosure in water so that the head of water above the lowest portion of the enclosure is a minimum 1 m, while the highest portion is a minimum 150 mm. Duration of the test will be 30 minutes. 

Exposure tests of 5-years duration in the atmosphere and during immersion in fresh water or sea-water by Welding Institute and by Stanners and Watkins have indicated the best paint systems for aluminium-coated steel. For immersed conditions two systems giving good performance are ... 

The stability of the solid-state Ca(II)-ISE was evaluated by immersing the electrode continuously in pulp filtrate for 9 days. The electrode was removed from the pulp filtrate only to make a three-point calibration once per day. The slope was found to be stable (27 +1 mV/decade) for the whole duration of the test (9 days), and the drift of the standard potential was ca. 1 mV/day. 

The international method for resistance to liquids is ISO 1817 [7], which has been revised [1], The method gives general clauses covering conditioning, choice of test liquid, temperatures and duration of test, and then details separate routines for determining the change in physical properties. ISO 1817 specifies two procedures for determination of tensile properties and hardness, one immediately after immersion and the other after immersion and subsequent drying. 

Schroder and co-workers [87] instead developed a method of assessing oxidative stability duration based on autoclave immersion at 60 and 80 °C and 1.2 and 5 MP oxygen concentration. Results of such accelerated tests were evaluated by means of a modified Arrhenius equation. With autoclaving, results can usually be obtained in a period of time not exceeding 12 months as opposed to the many years of testing needed by conventional testing at 0.1 MPa. The basis for the calculation of polymer lifetime is based on exposure duration for 50% loss of residual maximum tensile load. 

Maconachie (1934) noted that Cox s results applied only to a 15-day test and did not define the influence of duration of exposure within this time. Maconachie immersed 99.99% zinc specimens in distilled water aerated by movement of the test assembly for 7 days at temperatures of SO-SO C. Weight losses were determined on specimens removed at daily intervals. At 20°C the distilled water had a pH of 5.2, largely as a result of dissolved carbon dioxide. At the higher test temperatures, however, the pH was probably higher as the carbon dioxide was expelled from the solution. The total corrosion as a function of temperature is shown at daily intervals in Fig. 3.4. The general shapes of the curves resemble those reported by Cox (1931) for 15 days and... 

---