Corrosion testing ASTM Standards

Laboratory Corrosion Test. The laboratory test procedure for the determination of corrosion rates of coal slurry used in this study was adapted from the method developed by Bomberger (26). The corrosion rates were determined by using ASTM Standard Corrosion Test, also known as the Total Immersion Method (27). The Bomberger technique consists of keeping coal slurry in suspension in a two-liter reaction vessel at a constant temperature. The corrosion rates are determined either by actual weight loss of steel coupons... 

Standard corrosion tests such as those developed by ASTM, NACE, and ISO often will address the technical requirements established in the goals and objectives though, in some cases, they may need to be modified. The quality of data produced by standard tests has been well established by critical evaluation and review, and results can readily be compared to others obtained using the same test. Even the highly specialized techniques used in fundamental corrosion research, while not especially amendable to standardization, eventually achieve codification through continued publication and use [9,17-20. ... 

ASTM G 49, Recommended Practice for Preparation and Use of Direct Tension Stress-Corrosion Test Specimens— This presents the design, preparation, and use of ASTM standard tension test specimens for investigating susceptibiUty to SCC. Specimens are generally tested in a selected environment imder axial load conditions until fracture occurs. This standard describes the apparatus for providing the load to the stressed specimens along with exposure considerations and inspection methods. 

Haynes, G. S., Review of Laboratoiy Corrosion Tests and Standards, Corrosion Testing and Evaluation Silver Anniversary Volume, ASTM STP 1000, R. Baboian and S. W. Dean, Eds., ASTM International, West Conshohocken, PA, 1990. 

Annual Book of ASTM Standards, Metal Test Methods and Analytical Procedures, Vol. OS. 02, Wear and Erosion, Metal Corrosion, 1990. 

Factors may throw off these rates—these are outlined in ASTM G3I, Standard Practice for Laboratory Immersion Corrosion Testing of Metals. Coupon-type tests cannot be correlated with changing plant conditions that may dramaticahy affect process equipment lifetimes. Other methods must be used if more frequent measurements are desired or correlation with plant conditions are necessary. 

Annual Book of ASTM Standards Metals-Physical, Mechanical and Corrosion Testing... 

A detailed and well-referenced account of electrochemical methods of testing has been written by Dean, France and Ketcham in a section of the book by Ailor. ASTM G5 1987 outlines standard methods for making potentiostatic and potentiodynamic anodic polarisation measurements and ASTM G3 1974 (R1981) gives conventions applicable to electrochemical measurements in corrosion testing. 

Because sodium, which is liquid between about 100°C and 881°C, has excellent properties as a heat-transfer medium, with a viscosity comparable with that of water and superior heat conductivity , much attention has been paid to liquid sodium corrosion testing of metal and alloys. Indeed, ASTM have issued a Standard Practice which can be used for determination... 

A convenient size for a circular coupon is 3 8 cm dia., a thickness of 0 - 32 cm and a central hole of 1 1 cm. Although inherent in the philosophy of corrosion testing, the use of coupons with surfaces that simulate those in service has been found to be unsatisfactory owing to irreproducibility, and the standard procedure normally adopted is to abrade down to 120-grit. ASTM Method G4 1984 gives details of preparation of specimens, evaluation of replicate exposures and the application of statistical methods. 

A number of standards exist for the determination of some of these parameters. BS 1377 Part 3 1990 refers to methods of tests for soils for civil engineering purposes, and Part 9 refers to these and corrosivity tests in situ. It is significant that the standard draws attention to the fact that the results of the tests that are described should be interpreted by a specialist. ASTM tests for pH and resistivity of soil used for corrosion testing are covered by G51 1977(R1984) and G57 1978 (R1984), respectively. 

Corrosion standards, including test methods, in use in Europe, including national, ISO, ASTM, NACE and CEN documents up to the year 1990 are described in the conference proceedings Corrosion Standards European and International Developments , P. McIntyre and A. D. Mercer, eds. The Institute of Metals, London (1991). 

ASTM G4 (latest revision) gives guidance for conducting plant corrosion tests, and in particular, for various methods for mounting specimens (coupons) in process plant. This standard evolved from ASTM and NACE Technical Committees. 

A plot of mass loss versus time can provide information about changes in the conditions under which the test has been run. One example of such a plot comes from the ASTM Standard G96, Standard Guide. As mentioned previously, weight loss measurements are appropriate for measurement of localized pitting corrosion, including that caused by MIC. 

A common chemical laboratory test for corrosion resistance is a simple exposure test using metal coupons. The ASTM standard G48 —Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride Solution—describes a simple exposure test. The material coupons (e.g., 60 x 60 mm) are placed on a glass cradle and immersed in the solution in such a way that the coupons are evenly exposed. 

With small modifications, ASTM standard G48 can be used to determine a CPT. The test is used as a ranking parameter for the resistance to pitting of high-alloyed austenitic stainless steels. In this method, material coupons are typically exposed for 24 or 72 h to a 6% FeCl3 (=1.11 mole/liter) solution at fixed temperatures (typically with 2.5°C intervals). The CPT is defined as the lowest temperature at which the specimen is attacked by pitting corrosion. 

R. G. Kelly, in Corrosion Tests and Standards Application and Interpretation, Ed by R. Baboian, ASTM Manual Series, MNL 20 (1995) 166. 

Corrosive sulfnr componnds can be detected by their effect on copper and the form in which the general copper strip corrosion test (ASTM D1838) for petrolenm prodncts is applied to liqnefied petrolenm gas. Hydrogen sulfide can be detected by its action on moist lead acetate paper, and a procedure is also used as a measure of sulfur compounds. The method follows the principle of the standard Doctor test. 

Panels of high strength aluminum alloy (7075-T6) were used in this study. The panels were approximately 10 x 3 x 0.032 inch (25 x 7.5 x 0.08 cm) in size. The test environments for coating evaluation were (1) a 5% NaCl spray (fog) chamber according to ASTM Standard Method of Salt Spray (Fog) Testing (B117-73), and (2) a modified 5% NaCl/S02 spray (fog) chamber with SO gas introduced periodically - ASTM Standard Practice for Modified Salt Spray (Fog) Testing (G85-84(A4)). In the latter case, a constant spray of 5% NaCl was maintained in the chamber and SO2 was introduced for one hour four tines a day (every 6 hours)( ). Coated test panels were examined for corrosion after one- and two- eek exposure periods. 

Ketcham, S. J. and Jankowsky, E. J., "ASTM Symposium on Laboratory Corrosion Tests and Standards", Bal Harbor, FL, 14-17 Nov. 1983. Glass, A. L., "A Radiochemical Investigation of the Leaching of Cr from Chemically Chromated A1 Alloy Surfaces, Part III, The "Uptake" of the Chloride Ion Into Such Surfaces," Naval Air Development Center, Warminster, PA Report No. NADC-MA-6702, August 1967. 

Several ASTM Standard Specifications have been promulgated for hafnium materials B737-90 for Hot-Rolled or Cold-Finished Hafnium Rod and Wire B776-91 for Hafnium and Hafnium Alloy Strip, Sheet, and Plate G2-88 and G2M-88 (metric) for Corrosion Testing of Products of Zirconium, Hafnium,... 

Feb 1948) 225 (March 1948) 219 (April 1948) (The Corrosion Forum) 17) ASTM Standards 1949. Part 1, p 865, Test A224-46 (Recommended Practice for Conducting Plant Corrosion Tests)... 

ASTM G 3-89, Standard Practice for Conventions Applicable to Electrochemical Measurements in Corrosion Testing, American Society for Testing and Materials, Philadelphia, PA, USA, 1989, pp 56-64. 

Test methods for corrosivity of water in the absence of heat transfer (electrical methods), D Annual Book of ASTM Standards 03.02, ASTM, pp. 2776-2779. 

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