ASTM E1382 : 97(2023)

Standard Test Methods for Determining Average Grain Size Using Semiautomatic and Automatic Image Analysis

Standard Details

1.1 These test methods are used to determine grain size from measurements of grain intercept lengths, intercept counts, intersection counts, grain boundary length, and grain areas.

1.2 These measurements are made with a semiautomatic digitizing tablet or by automatic image analysis using an image of the grain structure produced by a microscope.

1.3 These test methods are applicable to any type of grain structure or grain size distribution as long as the grain boundaries can be clearly delineated by etching and subsequent image processing, if necessary.

1.4 These test methods are applicable to measurement of other grain-like microstructures, such as cell structures.

1.5 This standard deals only with the recommended test methods and nothing in it should be construed as defining or establishing limits of acceptability or fitness for purpose of the materials tested.

1.6 The sections appear in the following order:

Section	Section
Scope	1
Referenced Documents	2
Terminology	3
Definitions	3.1
Definitions of Terms Specific to This Standard	3.2
Symbols	3.3
Summary of Test Method	4
Significance and Use	5
Interferences	6
Apparatus	7
Sampling	8
Test Specimens	9
Specimen Preparation	10
Calibration	11
Procedure:
Semiautomatic Digitizing Tablet	12
Intercept Lengths	12.3
Intercept and Intersection Counts	12.4
Grain Counts	12.5
Grain Areas	12.6
ALA Grain Size	12.6.1
Two-Phase Grain Structures	12.7
Procedure:
Automatic Image Analysis	13
Grain Boundary Length	13.5
Intersection Counts	13.6
Mean Chord (Intercept) Length/Field	13.7.2
Individual Chord (Intercept) Lengths	13.7.4
Grain Counts	13.8
Mean Grain Area/Field	13.9
Individual Grain Areas	13.9.4
ALA Grain Size	13.9.8
Two-Phase Grain Structures	13.10
Calculation of Results	14
Test Report	15
Precision and Bias	16
Grain Size of Non-Equiaxed Grain Structure Specimens	Annex A1
Examples of Proper and Improper Grain Boundary Delineation	Annex A2

1.7 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.

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