ASTM E() – Standard Test Methods for Determining Average Grain Size Using Semiautomati. Purchase your copy of ASTM E – 97() as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards. The ASTM Designation: E–97 requires five hundred data points for a given sample and this analysis is time-consuming and tedious for the.
|Published (Last):||25 December 2014|
|PDF File Size:||3.65 Mb|
|ePub File Size:||9.3 Mb|
|Price:||Free* [*Free Regsitration Required]|
Minor image editing would be required before measurement.
Calculate the grain size number based on the mean of the measurements using Table 2 or the equations in Table 3. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
A variety of approaches can be employed. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Current edition zstm Nov. L is the number of grains intercepted per unit length. The grain structure was measured on each? The square root of the pooled variance is the pooled standard deviation.
Test Methods E and Ref 1 3 list many suitable etchants. If the test line should intersect a junction between four grains, which occurs rarely, count this intersection twice, that is, as 2 intersections. For example, for optically anisotropic materials that are difficult to etch, crossed polarized light may be required to observe the grain structure. If the histogram reveals a duplex condition, calculate s wstm the intercepts within each region of the distribution curve.
Certain electrolytic etching techniques, 3,4 as summarized in Ref 1 will delineate the grain boundaries but not the twin boundaries thus permitting use of automatic image analysis.
Delete all grains intersecting the test area border from the image so that partial chord lengths within these grains are not measured. For counting grain boundary intersections or grains intercepted, a circular test grid, such as described in Test Methods E, may be used. There may be other methods or alternate e182 that can produce acceptable results but they must be ee1382 evaluated before use see These methods are based on certain rules to decide which grains that intersect the test area border are fully sized or not sized at all.
Note that of the three principle planes, that is, A? Take the micrographs at random, that is, without bias in the?
For accurate measurement of intercept lengths or grain areas, the smallest grains should be at least 5 mm in diameter on the television monitor 9 for a typical — mm 12—13 in. Determine the average enlargement factor of the measured features and multiply this value by the magni? If this cannot be done, count every other triple point intersection twice. This is easily performed, without producing bias, if enlargements are used.
If the degree of grain elongation is of interest, measure the average chord length parallel and perpendicular to the deformation direction in the same manner as described in Grains intersecting the test area border must be deleted see Table 1.
L for a single phase grain structure. All grains intersecting the test area border should be deleted from the image.
However, no corrections are made to the size of the original test area and its relationship to the area of the grains included astmm the measurement is unknown. If directed test lines were used on one, two or three planes, determine the mean of the measurements and any desired anisotropy ratios.
ASTM E1382 – 97(2015)
If measurements were made using only the longitudinal plane, determine the mean value of the measurements. A values for the? Fix each micrograph to the tablet surface, for example using masking tape, to prevent movement during analysis.
Round off the value of G to the? For such specimens, semiautomatic digitizing tablet measurements are preferred. Counting accuracy will be impaired if the number of grains visible is excessively high smaller apparent size in the? If the cursor can be programmed to record each triple point intersection as 11? Specimens must be carefully cleaned and dried after polishing. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
It is assumed ashm when a number of? The choice of the proper etchant depends on the composition and heat treatment condition of the specimen. To minimize operator fatigue, and to ensure measurement accuracy, the smallest grain on the photomicrograph should be about 5 mm in diameter.
Measure the area of this grain, Amax, by selecting it with a light pen, mouse, or track ball. There are a number of missing grain boundaries that must be added before measurement.
Moderate image editing is required. For automatic image analysis, a?
Most digitizing tables have software programs established for such computations. Each micrograph should contain at least?
For such structures, use the lowest possible magni? For measuring intercept lengths, a test grid with a number of equally spaced straight, parallel lines is used.
Use of a programmable stage prevents bias in? Prices subject to change without notice. Again, if each directed P intercept value and the mean value,? These equations measured parameters: