ASTM G97

This test is a guide for evaluating magnesium anodes. The degree of correlation between this test and service performance has not been fully determined.

1. Scope

1.1 This test method covers a laboratory procedure that measures the two fundamental performance properties of magnesium sacrificial anode test specimens operating in a saturated calcium sulfate, saturated magnesium hydroxide environment. The two fundamental properties are electrode (oxidation potential) and ampere hours (Ah) obtained per unit mass of specimen consumed. Magnesium anodes installed underground are usually surrounded by a backfill material that typically consists of 75 % gypsum (CaSO₄·2H₂O), 20 % bentonite clay, and 5 % sodium sulfate (Na₂SO₄). The calcium sulfate, magnesium hydroxide test electrolyte simulates the long term environment around an anode installed in the gypsum-bentonite-sodium sulfate backfill.

1.2 This test method is intended to be used for quality assurance by anode manufacturers or anode users. However, long term field performance properties may not be identical to property measurements obtained using this laboratory test.

Note 1—Refer to Terminology G 15 for terms used in this test method.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautions, See Section 7 and Paragraph 8.1.1.

2. Referenced Documents

ASTM Standards
D1193 Specification for Reagent Water
G15 Terminology Relating to Corrosion and Corrosion Testing
G16 Guide for Applying Statistics to Analysis of Corrosion Data
G3 Practice for Conventions Applicable to Electrochemical Measurements in Corrosion Testing
American National Standard
ANSI/NFPA480 Storage, Handling, and Processing of Magnesium, 1987 Edition

Index Terms

coulometer; electroplater's tape; sacrificial anode; Ampere hours; Anodes; Backfill--testing; Corrosion; Current measurement; Electrodes; Laboratory analysis/evaluation; Magnesium; Magnesium anodes; Oxidation testing; Performance--metals/alloys materials/applications; Saturated calcium sulfate/magnesium hydroxide environments; Underground environments; ICS Number Code 77.150.20 (Magnesium products)

Citing ASTM Standards

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