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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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A reasonable estimate of the grain size may be obtained by measurements made on the longitudinal plane only, depending upon the manner in which the grain shape has been distorted. It should be recognized that slight differences in grain size ratings may be obtained using different methods because different aspects of the grain structure are being assessed. If the test line should intersect a junction between four grains, which occurs rarely, count this intersection twice, that is, as 2 intersections.

Annex A1 describes methods for measuring the grain size of non-equiaxed structures and for evaluating the degree of grain shape anisotropy. The grain boundary image can be thinned by erosion to delete any particles at the boundary and then this To minimize operator fatigue, and to ensure measurement accuracy, the smallest grain on the photomicrograph should be about 5 mm in diameter.

Image editing cannot be performed reliably. Alternatively, determine the degree of enlargement axtm comparing the size of e138 on the enlargement to their size on the contact print.

However, the presence of an equiaxed grain structure in a wrought specimen can only be determined by examination of a plane of polish parallel to the deformation axis. 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.


Count only whole grains within a known test area. Precision and Bias Grain contrast 1 and tint etchants 1,2 are very effective because they generally provide full delineation of the grain structure.

ASTM E()_图文_百度文库

Individual Chord Intercept Lengths. The grain structure is nearly completely revealed without the twin boundaries. No further reproductions authorized. If the grain structure is not equiaxed but elongated, then grain size measurements on specimens with different orientations will vary.

Divide each area, Ai, by the magni? Again, this technique works best with relatively coarse-grained steels. In general, coarse-grained specimens are more easily etched for prior-austenite grain size. Use of high magni? This procedure should be repeated on each of at least? Ais to be determined, it is not grain boundaries per unit area L necessary to delete the grains astn intersect the test area border, so long as the?

Next, divide Li by the true? E3182 directed test lines rather than random are used for intercept counts on non-equiaxed grains in plate or sheet type specimens, the required measurements can be made using only two principle test planes, rather than all three, due to the equivalence of test directions, as described in A1.

A sufficient number of? L value is converted to a lineal 9. NOTE 1—Equations 2 and 3 are for single phase grain structures. Automatic image analyzers are affected by these problems to a greater degree w1382 are semiautomatic digitizing tablet measurements. If a digitizing tablet is utilized for the measurements, illumination modes other than bright?

ASTM E1382 – 97(2015)

The test methods may be applied to specimens with equiaxed or elongated grain structures with either uniform or duplex grain size distributions. There may be other possible methods, or other equivalent procedures, that can be used to measure grain size. If each P to a mean lineal intercept length using Eq 5, and the mean?


Grains intersecting the test area border must be deleted see Table 1.

The faint annealing twins would interfere with automatic image analysis but not measurement with a digitizing tablet. Calculate the grain size number based on the mean of the measurements using Table 2 or the equations in Table 3.

Subjecting the specimen to a temper embrittlement cycle may enhance the etch response, but this treatment is not helpful if the amounts of P, Sn, As, and Sb are very low. Alternatively, the three mean lineal intercept lengths can be normalized divide each by the value of the smallest and the results expressed as ratios, as shown below. Detect the grain interiors in the manner described in Intercept and Intersection Counts.

A, is determined in accordance with Eq Anisotropy indexes for the two perpendicular test orientations on the transverse and planar surfaces revealed values of 0.

Avoid an excessively high number of grains per photograph as counting accuracy may be impaired. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. Sieving Including test sieves and porosimetry.

Methods based on the average grain area or the number of grains per unit area are directly related to the total length of grain edges per unit volume, LV. This value is equivalent to the mean lineal intercept length,?