GOST 21073.1-75
GOST 21073.1−75 ferrous Metals. Determination of grain size by comparison with the scale of microstructures (with Change No. 1)
GOST 21073.1−75
Group B09
INTERSTATE STANDARD
METALS NONFERROUS
Determination of grain size by comparison with the scale of microstructures
Non-ferrous metals. Determination of grain Size bu comparison with
microstructure scale
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 comparison with the scale of the microstructures to determine the grain size.
The method used for mass determination of grain size in terms of production.
The standard complies ST SEV 1959−79 method in comparison with the scale of microstructures.
(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 the surface of the cone browse multiple locations and choose three, and with non-uniform grain size not less than five cases.
2.2. To determine the amount of grain used three scales (see Annex 1). The use of a scale is determined by the highest similarity microstructure of the test piece and the scale.
Recommended to apply the scale shown in the table of Annex 2 if the application of those or other scales is not governed by the relevant standards steel.
2.3. In determining the value of the grain using 100-fold (linear) magnification microscope.
Allowed to use other magnification, if 100-fold increase in grain less than that of the microstructure 10 N or more than N of the microstructure 1. This used the increase when the grain size comparable with microstructure N 4−7. Defined in this case a number microstructure recount, leading to 100-fold increase.
For more accurate determination of grain size or when re-definitions on the same sample with different magnification is used. Grain size with all the increases in this case should be comparable to the microstructures of N 2−9.
2.4. The determination of the amount of grain produced by comparing the image in the eyepiece microscope on the frosted glass of the microscope or on photomicrographs with microstructure. At the same time determine the most similar the grain size of the microstructure.
2.5. If the structure of the sample of grains of two or more dimensions, forming clusters, determine the number of grains in these clusters and estimated proportion of area occupied by each grain size.
3. PROCESSING OF THE RESULTS
3.1. The result of the test taking room of the microstructure obtained at 100-fold (linear) increase.
When conditions specified in paragraph 2.5, the testing result accept two or more numbers showing the area percentage occupied by the grains each size. For example: the microstructure of N 3 (70%)+5 N (30%). Definition square grains of each size are produced visually.
Allowed to determine the limits of grain size.
For example:
microstructure N 3−5.
When using zoom other than 100-fold, the number of microstructures counted according to the formula
.
The coefficient allowed to determine the timetable (see Annex 3). The resulting recalculation number of microstructures are rounded to the nearest whole number.
For the most applicable magnification of microscope converted rooms of the microstructure is given in Appendix 1.
Measurement error should not be more than one number of the scale of the microstructure.
(Changed edition, Rev. N 1).
3.2. As reference values characterizing the grain size, by the numbers microstructures can be determined indicators: the number of grains, per 1 mm section, the average cross-sectional area of grains and the average diameter of the grains (see Annex 4).
ANNEX 1 (mandatory). CONTROL OF THE SCALE OF MICROSTRUCTURES
ANNEX 1
Mandatory
I |
||
II |
||
III |
The observed number of microstructure |
1 |
2 | ||||||||||
Linear increase |
25 |
50 |
75 |
100 |
200 |
400 |
25 |
50 |
75 |
100 |
200 |
400 |
Converted room of microstructure |
-3 |
-1 |
0 |
1 |
3 |
5 |
-2 |
0 |
1 |
2 |
4 |
6 |
The approximate diameter of grain, mm |
1,0 |
0,5 |
0,3 |
0,20 |
0,12 |
0,06 |
0,7 |
0,3 |
0,20 |
0,17 |
0,08 |
0,04 |
I |
||
II |
||
III |
The observed number of microstructure |
3 | 4 | ||||||||||
Linear increase |
25 |
50 |
75 |
100 |
200 |
400 |
25 |
50 |
75 |
100 |
200 |
400 |
Converted room of microstructure |
-1 |
1 |
2 | 3 | 5 | 7 | 0 | 2 | 3 | 4 | 6 | 8 |
The approximate diameter of grain, mm |
0,5 |
0,20 |
0,17 |
0,12 |
0,06 |
0,03 |
0,3 |
0,17 |
0,12 |
0,08 |
0,04 |
0,02 |
I |
||
II |
||
III |
The observed number of microstructure |
5 | 6 | ||||||||||
Linear led increase |
25 |
50 |
75 |
100 |
200 |
400 |
25 |
50 |
75 |
100 |
200 |
400 |
Converted room of microstructure |
1 |
3 |
4 |
5 |
7 |
8 |
2 |
4 |
5 |
6 |
8 |
10 |
The approximate diameter of grain, mm |
0,20 |
0,12 |
0,08 |
0,06 |
0,03 |
0,015 |
0,17 |
0,08 |
0,06 |
0,04 |
0,02 |
0,010 |
I |
||
II |
||
III |
The observed number of microstructure |
7 | 8 | ||||||||||
Linear increase |
25 |
50 |
75 |
100 |
200 |
400 |
25 |
50 |
75 |
100 |
200 |
400 |
Converted room of microstructure |
3 |
5 |
6 |
7 |
9 |
11 |
4 |
6 |
7 |
8 |
10 |
12 |
The approximate diameter of grain, mm |
0,12 |
0,06 |
0,04 |
0,03 |
0,015 |
0,007 |
0,08 |
0,04 |
0,03 |
0,02 |
0,010 |
0,005 |
I |
||
II |
||
III |
The observed number of microstructure |
9 | 10 | ||||||||||
Linear increase |
25 |
50 |
75 |
100 |
200 |
400 |
25 |
50 |
75 |
100 |
200 |
400 |
Converted room of microstructure |
5 |
7 |
8 |
9 |
11 |
13 |
6 | 8 | 9 | 10 | 12 | 14 |
The approximate diameter of grain, mm |
0,06 |
0,03 |
0,020 |
0,015 |
0,007 |
0,004 |
0,04 |
0,020 |
0,015 |
0,010 |
0,005 |
0,002 |
APPENDIX 2 (recommended). THE USE OF CONTROL SCALES FOR VARIOUS METALS
ANNEX 2
Recommended
Metal |
Control bar |
Aluminium and its alloys |
I |
Magnesium and its alloys |
I or III |
Copper and its alloys |
I, II or III |
Nickel and its alloys |
II or III |
Titanium and its alloys |
I or III |
Tin and its alloys |
I or III |
Lead and its alloys |
I or III |
Zinc and its alloys |
I or III |
APPENDIX 3 (recommended). Graph for determining the coefficient K, depending on the magnification of the microscope g
APPENDIX 3
Recommended
Graph for determining the coefficient according to
from zoom microscope
ANNEX 4 (reference). INDICATORS OF GRAIN SIZE
ANNEX 4
Reference
The average number of grains | |||||
Room micro |
Average diameter , mm |
Conditional average grain size , mm |
The average cross-sectional area of the grain , mm |
1 mmsquare section , mm |
1 mm |
-3 |
1,000 |
0,886 |
Of 1.00 |
1 |
1,0 |
-2 |
0,710 |
0,627 |
0,50 |
2 |
2,5 |
-1 |
0,500 |
0,443 |
0,25 |
4 |
8,0 |
0 |
0,353 |
0,313 |
0,125 |
8 |
22,6 |
1 |
0,250 |
0,222 |
0,0625 |
16 |
64,0 |
2 |
0,177 |
0.157 inch |
0,0313 |
32 |
181 |
3 |
0,125 |
0,111 |
0,0516 |
64 |
512 |
4 |
0,088 |
0,0783 |
0,00781 |
128 |
1,45·10 |
5 |
0,062 |
0,0554 |
0,00391 |
256 |
4,10·10 |
6 |
0,044 |
0,0392 |
0,00195 |
512 |
1,16·10 |
7 |
0,031 |
0,0277 |
0,00098 |
1024 |
3,28·10 |
8 |
0,022 |
0,0198 |
0,00049 |
2048 |
9,27·10 |
9 |
0,016 |
0,0138 |
0,000244 |
4096 |
2,62·10 |
10 |
0,011 |
0,0099 |
0,000122 |
8192 |
7,41·10 |
11 |
0,0078 |
0,0069 |
0,000061 |
16384 |
2,10·10 |
12 |
0,0055 |
0,0049 |
0,000031 |
32768 |
Of 5.97·10 |
13 |
0,0039 |
0,0035 |
0,000015 |
65536 |
Of 1.68·10 |
14 |
0,0028 |
0,0024 |
0,000008 |
131072 |
4,75·10 |
Note. The number of grains per 1 mmsquare section is calculated by the formula .
ANNEX 4. (Changed edition, Rev. N 1).