Corrosion test specimens, preparing

ASTM G 1 Recommended practice for preparing, cleaning and evaluating corrosion test specimens Preparation of test specimens for corrosion testing and evaluation of results... 

Recommended Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens," specification Gl, Annual Book ofASTM Standards, American Society for Testing and Materials, Philadelphia, Pa., 1992. 

Test method for sandwich corrosion test Recommended practice for preparing, cleaning, and evaluating corrosion test specimens Practice for aqueous corrosion testing of samples of zirconium and zirconium alloys Test method for corrosion testing of products of zirconium, hafnium and their alloys in water at 633 K or in steam at 673 K [metric] Recommended practice for conventions applicable to electrochemical measurements in corrosion testing... 

Recommended practice for examination and evaluation of pitting corrosion Test method for determining susceptibility to stress corrosion cracking of high-strength aluminium alloy products Test method for pitting and crevice corrosion resistance of stainless steels and related alloys by the use of ferric chloride solution Recommended practice for preparation and use of direct tension stress corrosion test specimens... 

G49, Standard Practice for Preparation and Use of Direct Tension Stress-Corrosion Test Specimens, ASTM, West Conshohoken, PA, 1995. 

Fig. 9.4 Bend beams specimen used in constant-deformation test [16]. Reprinted, with permission, from ASTM G 39-99 Standard Practice for Preparation and Use of Bent-Beam Stress-Corrosion Test Specimens copyright ASTM International, West Conshohocken, PA.

ASTM G1 Standard practice for preparing, cleaning evaluating corrosion test specimens (1990)... 

ASTM Gl 1990 Standard Practice for Preparing, Cleaning and Evaluating Corrosion Test Specimens... 

G 1 Preparing, Cleaning, and Evaluating Corrosion Test Specimens G 3 Conventions Applicable to Electrochemical Measurements in Corrosion Testing G 4 Conducting Corrosion Coupon Tests in Plant Equipment... 

G 58 Practice for the Preparation of Stress-Corrosion Test Specimens for Weldments... 

ASTM G 39, Practice for Preparation and Use of Bent-Beam Stress-Corrosion Test Specimens— This describes methods for design, preparation, and use of bent-beam stress-corrosion specimens. This standard covers apparatus for supporting specimens, basic design of a specimen, stress calculations, test conditions, exposure, and inspection techniques. 

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. 

ASTM G 58, Practice for Preparation of Stress Corrosion Test Specimens for Weldments— This covers the manufacture and application of welded test specimens in stress corrosion testing. This practice is used to evaluate a total weldment, weld metal, or presence of notches and stress risers in weldments with respect to SCC in an environment. In addition, ASTM G 58 contains a method for evaluating the critical stress levels that will produce SCC in a weldment. The specimens are evaluated after exposure to an environment by microscopic methods. This standard includes typical specimens (stressed and tension), welding considerations, test specimen preparation, and inspection after exposure. 

Where corrosion test specimens are used, care is required in the preparation, identification, cleaning, and evaluation to ensure reasonable reliability and accuracy of the data. These requirements are well detailed in ASTM G 4, Guide for Conducting Corrosion Tests in Field Applications. 

Corrosion test specimens are used to evaluate average corrosion rate over the exposure period and eire also useful for assessment of crevice corrosion, pitting, and end grain attack, and may be used for metallographic examination of the corrosion test specimen or analysis of any deposits. Special corrosion test specimens may be prepared with welds to assess corrosion problems particular to weld material or heat affected zones. SCC may be monitored with specially mounted and loaded corrosion test specimens. 

The simplest uniform corrosion tests are those based on coupon immersion and mass loss tests. The tests provide data on the uniform metallic corrosion rate most often expressed in English units as mils per year (mpy) or in metric units as millimeters per year (mm/y). While there are various standards for such tests, the predominant methods are those prescribed by ASTM G 1, "Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens. This standard contains a comprehensive reference list of other ASTM standards that also apply, depending on the type of tests of interest to the investigator. 

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