ASTM G31-21 - 1.1.2021
 
Significance and Use

4.1?Corrosion testing by its very nature precludes complete standardization. This standard, rather than a standardized procedure, is presented as a guide so that some of the pitfalls of such testing may be avoided.

4.2?Experience has shown that all metals and alloys do not respond alike to the many factors that affect corrosion and that accelerated corrosion tests give indicative results only, or may even be entirely misleading. It is impractical to propose an inflexible standard laboratory corrosion testing procedure for general use, except for material qualification tests where standardization is required. One purpose for this guide is to promote better correlation of results in the future and the reduction of conflicting reports through a more detailed recording of meaningful factors and conditions.

4.3?In designing any corrosion test, consideration should be given to the various factors discussed in this guide, because these factors have been found to affect the results obtained.

 
1. Scope

1.1?This guide covers and describes the factors that influence laboratory immersion corrosion tests, particularly mass loss tests. These factors include apparatus, sampling, test specimen, test conditions (test solution composition, temperature, gas sparging, fluid motion, solution volume, method of supporting test specimens, duration of test), methods of cleaning test specimens, interpretation of results, and calculation of corrosion rates. This guide also emphasizes the importance of recording all pertinent data and provides a checklist for reporting test data.

1.2?The specific evaluation of localized attack, environmentally assisted cracking, and effects of solution flow are not within the scope of this guide.

1.3?This guide is intended to be used by those designing laboratory immersion tests who may not be familiar with all of the variables to consider and the pitfalls that could be encountered when designing and conducting this kind of testing. It should be used as a reference to ensure that the test will allow generation of data relevant to the application with the minimum of interferences.

1.4?The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.5?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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

 
2. Referenced Documents

G66-23

Standard Test Method for Visual Assessment of Exfoliation Corrosion Susceptibility of 5XXX Series Aluminum Alloys (ASSET Test)

ISO 3651-2

Determination of resistance to intergranular corrosion of stainless steels - Part 2: Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels - corrosion test in media containing sulfuric acid

A262-15(2021)

Standard Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels

E8-04

Standard Test Methods for Tension Testing of Metallic Materials

G34-23

Standard Test Method for Exfoliation Corrosion Susceptibility in 2XXX and 7XXX Series Aluminum Alloys (EXCO Test)

G46-21

Standard Guide for Examination and Evaluation of Pitting Corrosion

G48-11(2020)e1

Standard Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride Solution (Includes all amendments and changes 12/17/2020).

ISO 8993

Anodized aluminum and aluminum alloys - Rating system for the evaluation of pitting corrosion - Chart method

ISO 3651-1

Austenitic Stainless Steels - Determination of resistance to intergranular corrosion of stainless steels - Part I: Austenitic and ferritic-austenitic (duplex) stainless steels - Corrosion test in nitric acid medium by measurement of loss in mass (Huey test)

G71-81(2019)

Standard Guide for Conducting and Evaluating Galvanic Corrosion Tests in Electrolytes

G107-95(2020)e1

Standard Guide for Formats for Collection and Compilation of Corrosion Data for Metals for Computerized Database Input (Includes all amendments and changes 12/17/2020).

G108-23

Standard Test Methods for Electrochemical Reactivation (EPR) for Detecting Sensitization of AISI Type 304 and 304L Stainless Steels

G112-22

Standard Guide for Conducting Exfoliation Corrosion Tests in Aluminum Alloys

G67-24

Standard Test Method for Determining the Susceptibility to Intergranular Corrosion of 5XXX Series Aluminum Alloys by Mass Loss After Exposure to Nitric Acid (NAMLT Test)

G116-99(2020)e1

Standard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosion (Includes all amendments and changes 12/17/2020).

G135-95(2001)

Standard Guide for Computerized Exchange of Corrosion Data for Metals

G170-06(2020)e1

Standard Guide for Evaluating and Qualifying Oilfield and Refinery Corrosion Inhibitors in the Laboratory (Includes all amendments and changes 12/10/2020).

G184-06(2020)e1

Standard Practice for Evaluating and Qualifying Oil Field and Refinery Corrosion Inhibitors Using Rotating Cage (Includes all amendments and changes 12/17/2020).

G185-06(2020)e1

Standard Practice for Evaluating and Qualifying Oil Field and Refinery Corrosion Inhibitors Using the Rotating Cylinder Electrode (Includes all amendments and changes 12/17/2020).

ISO 8994

Anodized aluminum and aluminum alloys - Rating system for the evaluation of pitting corrosion - Grid method

ISO 9400

Nickel-based alloys - Determination of resistance to intergranular corrosion

ISO 11463

Corrosion of metals and alloys - Evaluation of pitting corrosion

ISO 11845

Corrosion of metals and alloys - General principles for corrosion testing

ISO 11846

Corrosion of metals and alloys - Determination of resistance to intergranular corrosion of solution heat-treatable aluminum alloys

ISO 11881

Corrosion of metals and alloys - Exfoliation corrosion testing of aluminum alloys

SP0690

Standard Format for Collection and Compilation of Data for Computerized Material Corrosion Resistance Database Input

ISO 8407

Corrosion of metals and alloys - Removal of corrosion products from corrosion test specimens

G110-92(2022)e2

Standard Practice for Evaluating Intergranular Corrosion Resistance of Heat Treatable Aluminum Alloys by Immersion in Sodium Chloride + Hydrogen Peroxide Solution (Includes all amendments and changes 1/31/2023).

G78-20

Standard Guide for Crevice Corrosion Testing of Iron-Base and Nickel-Base Stainless Alloys in Seawater and Other Chloride-Containing Aqueous Environments

G82-98(2021)e1

Standard Guide for Development and Use of a Galvanic Series for Predicting Galvanic Corrosion Performance (Includes all amendments and changes 1/21/2021).

D1193-06(2018)

Standard Specification for Reagent Water

E300-03(2022)

Standard Practice for Sampling Industrial Chemicals

G1-03(2017)e1

Standard Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens (Includes all amendments and changes 12/8/2017).

G28-22

Standard Test Methods for Detecting Susceptibility to Intergranular Corrosion in Wrought, Nickel-Rich, Chromium-Bearing Alloys

ISO 6509

Corrosion of metals and alloys - Determination of dezincification resistance of brass