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.
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If measurements were made on only a single plane, for example, the longitudinal plane, report astj this was done and the nature of the test method, plus the statistical evaluation of the data. The grain elongation ratio, e13882 anisotropy index, AI, is de? The presence of twin boundaries can be tolerated when semiautomatic digitizing tablets are utilized but measurement errors are more likely to occur. If directed test lines were used on one, two or three planes, determine the mean of the measurements and any desired anisotropy ratios.
L data and Eq A1.
Because of the aastm introduced by such procedures, they should be used with caution, or avoided, until their in?
Table 4 lists the values of t as a function of n or N.
The grain interiors are detected as described in Prior to automatic image analysis, the grain boundaries should be thinned and the etch pitting must be removed. This procedure is useful for showing the overall mean shape of the grains but does not give size information. L is the number of grain boundary intersections per unit length. The computed ASTM grain sizes are 9. Prices subject to change without notice.
ASTM E1382 – 97(2015)
To do this, sort the intercept lengths in ascending order, separate the data into the two individual distributions, and compute? Graphical data may be produced with either a printer or plotter, as desired. Depending on the method used, a mean value of the particular microstructural feature is determined which can be used to calculate, or estimate, the ASTM grain size number, G.
Measure areas of whole grains only. Methods based on the mean intercept length or the number of grain boundary intersections per unit length are directly related to the grain boundary surface area per unit volume, SV.
A substantial percentage of the grain boundaries are not visible and the annealing twins are revealed. If the grain size varies within the product, specimen and? L only will be presented. Automatic image analyzers are affected by these problems to a greater degree than are semiautomatic digitizing tablet measurements. Excessive relief, pitting or pullout must be avoided. The number of intersections of the grain boundaries by the scan lines is determined.
Measure the entire area of the largest observed grain section. Grains intersecting the test area border must be deleted see Table 1. Such a computation is easy to perform if the data can be read into a spreadsheet type computer program. Use of a programmable stage prevents bias in?
Scratches from grinding, or from polishing with abrasives larger than about 1-? It is assumed that when a number of?
Grains intersecting the test area border do not need to be deleted. Intercept and Intersection Counts. In this case, the grain size must be determined on longitudinal, transverse, and planar surfaces, or radial and transverse surfaces, depending on the product shape, and averaged, as described in Annex A1, to obtain the mean grain size.
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.
Current edition approved Nov. Fix each micrograph to the tablet surface, for example using masking tape, to prevent movement during analysis. Prior to analysis, center the light source as described in the operating instructions for the microscope and adjust the?
A third approach is to transfer the microstructural image, test grid image and cursor image to a television monitor. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.
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.