GOST 21073.3-75
GOST 21073.3−75 ferrous Metals. Determination of grain size by the method of counting intersections of grains (with Change No. 1)
GOST 21073.3−75
Group B09
INTERSTATE STANDARD
METALS NONFERROUS
Determination of grain size by the method of counting intersections bean
Non-ferrous metals. Determination of grain size bu calkulation
of grain intersections
AXTU 1709
Date of introduction 1976−07−01
Resolution The state Committee of standards of Ministerial Council of the USSR from 15 August 1975 N 2164 the introduction of set with 01.07.76
Restriction expiration removed by Protocol No. 2−92 of the Interstate Council for standardization, Metrology and certification (ICS 2−93)
EDITION with Change No. 1, approved in December 1983 (ICS 3−84).
Real the standard applies to non-ferrous metals and sets the method counting the crossings of the grains to determine the grain size.
Method used to quantify the magnitudes of the conditional dimensions neravnovesnykh or equiaxed grains, for example for research or experimental work, etc.
The standard complies ST SEV 1959−79 in the method of counting intersections of grains.
(Changed edition, Rev. N 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for test method — according to GOST 21073.0−75.
2. TESTING
2.1. For the determination of grain size by the method of counting intersections bean the section surface view and choose at least five typical places, and at definition of statistical characteristics 
(Changed edition, Rev. N 1).
2.2. The determination of the amount of grain produced at this magnification to field of view was entirely 80−200 beans.
2.3. For measurements used a secant line in the form of two non-parallel straight or circle. Video secant must intersect at least 10 grains, and secant to a circle not less than 20 grains.
2.4. Secant lines is applied to the image of the measured locations, observed on the frosted glass of the microscope, on photomicrographs, or directly at the eyepiece of the microscope (if the eyepiece is provided with images that can to be used as clipping).
2.5. Determination of neravnovesnykh bean carried out on thin sections, made along and across the main axis of symmetry of the product. In this the case of a secant line in the form of direct spend parallel to the axes of symmetry.
(Added, Rev. N 1).
3. PROCESSING OF THE RESULTS
3.1. The determination of the amount of grain produced with the counting of grain boundaries crossed by the clipping.
The difference during the counting of grain boundaries on the same socket, and if neravnovesnykh bean — each of the three axes of symmetry should not be more than 50%.
3.2. For the result of the determination to accept one or more values:
conditional average grain size , mm.
If the grain neravnovesnoi may be determined by the average grain size for each of the three main measurements;
conditional minimum and maximum grain size and
, respectively, mm;
the standard deviation of individual measurements of the relative size of grain , mm.
3.3. The calculation produced by the formula
