Civil

Designation: E 7 – 00

Standard Terminology Relating to

Metallography1

This standard is issued under the fixed designation E 7; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial changesince the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense.

1. Scope 1.1 This standard covers the definition of terms, acronyms, and symbols used in ASTM documents related to the field of metallography and metallographic testing. Terms that are only relevant to a particular standard or that are adequately defined in a general dictionaryare not defined in this terminology standard. 1.2 This standard includes terminology used in metallographic areas, such as, but not limited to: light microscopy, microindentation hardness testing, specimen preparation, x-ray and electron metallography, quantitative metallography, photomicrography, and determination of grain size and inclusion content. 1.3 This standard may be of use to individualsutilizing standards of Committee E-4 as well as by those in need of a general reference source for terminology in the field of metallography. 2. Referenced Documents 2.1 ASTM Standards: E 14 Practice for Thermal Analysis of Metals and Alloys2 E 45 Test Methods for Determining the Inclusion Content of Steel3 E 80 Practice for Dilatometric Analysis of Metallic Materials4 E 92 Test Method for VickersHardness of Metallic Materials3 E 112 Test Methods for Determining Average Grain Size3 E 1122 Practice for Obtaining JK Inclusion Ratings Using Automatic Image Analysis3 3. Significance and Use 3.1 Standards of Committee E-4 consist of test methods, practices, and guides developed to ensure proper and uniform testing in the field of metallography. In order for one to
1 This terminology is under thejurisdiction of ASTM Committee E04 on Metallography and are the direct responsibility of Subcommittee E04.02 on Metallographic Terminology and Nomenclature of Phase Diagrams. Current edition approved July 10, 2000. Published September 2000. Originally published as E 7 – 26 T. Last previous edition E 7 – 99b. 2 Annual Book of ASTM Standards, Vol 04.01. 3 Annual Book of ASTM Standards, Vol 03.01. 4Discontinued; see 1984 Annual Book of ASTM Standards, Vol 14.02. Replaced by E228.

properly use and interpret these standards, the terminology used in these standards must be understood. 3.2 The terms used in the field of metallography have precise definitions. The terminology and its proper usage must be completely understood in order to adequately communicate in this field. In this respect,this standard is also a general source of terminology relating to the field of metallography facilitating the transfer of information within the field. 4. Terminology absorption—the decrease in intensity which radiation undergoes during its passage through matter when the ratio of transmitted or reflected luminous flux to incident is less than 1. absorption coefficient—specific factor characteristic of asubstance on which its absorption radiation depends. The rate of decrease of the natural logarithm of the intensity of a parallel beam per unit distance traversed in a substance. For X-rays, the linear absorption coefficient is the natural logarithm of the ratio of the incident intensity of an X-ray beam incident on unit thickness of an absorbing material to the intensity of the beam transmitted.If Ieis the incident intensity of a beam of X-rays, Itthe transmitted intensity, and X the thickness of the absorbing material, then:
It 5 Ieexp~2µX! (1)

Here µ is the linear absorption coefficient. The mass absorption coefficient is given by µ/r where r is the density. absorption edge—an abrupt change in absorption coefficient at a particular wavelength. The absorption coefficient is always...