ASTM chemical environment test

ASTM Chemical Environment Test Standards. Since intergranular corrosion is one of the most serious problems in the satisfactory application of stainless steels, several procedures are available for the measurement of the susceptibility of these steels to this type of corrosion. The procedures have been formalized as standardized tests, designated as ASTM A 262 (Ref 102), and are widely accepted as a basis for certifying that a specific stainless steel meets specifications. A limitation of these tests is that they specify specific environments rather than the environment of the actual application. In many applications, however, reasonable correlations have been established between acceptable response to the tests and successful service performance. 

In applications where possible degrading elements exist, candidate adhesives must be tested under simulated service conditions. Standard lap shear tests, such as ASTM D1002, which use a single rate of loading and a standard laboratory environment, do not yield optimal information on the service life of the joint. Important information such as the maximum load that the adhesive joint will withstand for extended periods and the degrading effects of various chemical environments are addressed by several test methods. Table 15.2 lists common ASTM environmental tests that are often reported in the literature. 

Generalized cross section of an ocean sedimentary/chemical environment. (From Rau, G., and Chaney, R.C., Triaxial testing of marine sediments with high gas contents. In Advanced Triaxial Testing of Soil and Rock, ASTM STP 977, Donaghe, R.T., Chaney, R.C., and Silver, M.L., eds., American Society for Testing and Materials, Philadelphia, PA, 338-352,1988. Reprinted with permission from ASTM.)... 

ASTM D-1822 type tensile impact samples were employed to obtain the data in Tables 3-20 and 3-21. Five bars were tested for each chemical environment. A control sample of five bars was also tested and tensile strength calculated. At the end of one week (168 1 h) the test bars were... 

It is cautioned, however, that these generalized SCC ratings can invcdve an oversimfdification in r ard to the perfarmance in unusual chemical environments. In this rating system, a quantitative (numaical) ranking was avoided because current SCC test methods do not justify finite values. Table 4 contains a tabulation of alloys and tempers, product forms, and stressing directions, with the classification of each into one of four categories fixim ASTM G 64. 

With materials like the stainless steels, which may be either active or passive in a test environment, it is common practice to produce a particular initial level of passivity or activity by some special chemical treatment prior to exposure. With stainless steels this objective may be subsidiary to eliminating surface contamination, such as iron from processing tools, by treatment in a nitric acid solution which might also be expected to achieve substantial passivity incidental to the cleaning action (ASTM A380 1988). 

These test procedures and standards are subject to change, so it is essential to keep up to date if one has to comply with them. It may be possible to obtain the latest issue on a specific test (such as a simple tensile test or a molecular weight test) by contacting the organization that issued it. For example, the ASTM issues new annual standards that include all changes. Their Annual Books of ASTM Standards contain more than seven thousand standards published in sixty-six volumes that include different materials and products. There are four volumes specifically on plastics 08.01-Plastics 1 08.02-Plastics 11 08.03-Plastics III, and 08.04-Plastic Pipe and Building Products. Other volumes include information on plastics and RPs. The complete ASTM index are listed under different categories for the different products, types of tests (by environment, chemical resistance, etc.), statistical analyses of different test data, and so on (56,128,129). 

Branson DR. 1978. Predicting the fate of chemicals in the aquatic environment from laboratory data. ASTM Spec Tech Publ 657. American Society for Testing and Materials, Philadelphia, PA., 55-70. 

Water Solubility, Soil Sorption, Octanol-Water Partitioning, and Concentration of Chemicals In Biota," Aquatic Toxicology, ASTM STP 707, Eaton, J.G. Parrish, P.R. Henrlcks, A.C., Eds. American Society for Testing and Materials, 1980 pp. 78-115. (The Kqj, data and the Kqj, regression equation are also given In Kenaga, E.E. Ecotoxlcol. Environ. Saf. 1980, 26-38). 

Finding a Method Various organizations publish volumes of methods for chemical analysis. One of the most well known is the American Society for Testing and Materials, or ASTM. The ASTM is a not-for-profit organization that provides a forum for producers, users, and consumers, to write standards for materials, products, systems, and services. The ASTM (Figure 5.19) publishes standard test methods encompassing metals, paints, plastics, textiles, petroleum, construction, energy, the environment, consumer products, medical services and devices, computerized systems, electronics, and many other areas. More than 10,000 ASTM standards are published each year in the 72 volumes of the Annual Book of ASTM Standards. Individual standards are also available. 

The Materials Technology Institute of the Chemical Process Industry (MTI) has identified five corrosion tests for iron- and nickel-based alloys, out of which two concern the resistance to crevice corrosion. The method MTI-2, originating from ASTM G48, involves the use of 6% ferric chloride solution for determining the relative resistance of alloys to crevice corrosion in oxidizing chloride environment. The method MTI-4 uses an increase in neutral bulk Cl- concentration at eight levels, ranging from 0.1 to 3% NaCl, to establish the minimum critical Cl concentration that produces crevice corrosion at room temperature (20-24°C).43,44... 

Fire retardancy of wood involves a complex series of simultaneous chemical reactions, the products of which take part in subsequent reactions. Most FRs used for wood increase the dehydration reactions that occur during thermal degradation so that more char and fewer combustible volatiles are produced. The mechanism by which this happens depends on the particular FR and the thermal-physical environment. The effectiveness of a FR treatment depends upon the performance rating of the treated material when tested in accordance with ASTM E84 (no greater flame spread than 25). 

Branson, D.R. (1978) Predicting the fate of chemicals in the aquatic environment from laboratory data. pp. 55-70. In Estimating the Hazard of Chemical Substances to Aquatic Life. ASTM Special Technical Publication 657. Cairns, J., Jr., Dickson, K.L., Maki, A.W., Editors, American Society for Testing and Materials, Philadelphia, Pennsylvania. 

Although published tests such as ASTM C-279 may be used to determine an acid brick s chemical resistance, no standard test exists to predict silica brick behavior. It is necessary to rely on personal experience or to evaluate a brick s performance in a simulated test environment. 

Shih, T. T., and Wei, R. P., Influences of Chemical and Thermal Environments on Delay in a Ti-6A1-4V Alloy, in Fatigue Crack Growth Under Spectrum Loads, ASTM STP 595, American Soc. of Testing and Materials, Philadelphia, PA (1976), 113-124. 

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