SR EN ISO 643:2020

Steels - Micrographic determination of the apparent grain size (ISO 643:2019)

This document specifies a micrographic method of determining apparent ferritic or austenitic grain size in steels. It describes the methods of revealing grain boundaries and of estimating the mean grain size of specimens with unimodal size distribution. Although grains are three-dimensional in shape, the metallographic sectioning plane can cut through a grain at any point from a grain corner, to the maximum diameter of the grain, thus producing a range of apparent grain sizes on the two-dimensional plane, even in a sample with a perfectly consistent grain size.


Status : Valid
Approval date : 4/30/2020
Number of pages : 30
ICS : 77.040.99 Other methods of testing of metals
Technical Committee : 42 - Steels and ferroalloy

Relations with other standards: