Kagat Other treatment conditions, such as as-hot rolled, as-hot forged, or as-cold drawn, may be tested as required but it must be recognized that the grain structure for these conditions may not aztm equiaxed. If the grain structure is not equiaxed but elongated, then grain size measurements on specimens with different orientations will vary. Automatic image analyzers are affected by these problems to a greater degree than are semiautomatic digitizing tablet measurements. The computed ASTM grain sizes are 9.
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Kagat Other treatment conditions, such as as-hot rolled, as-hot forged, or as-cold drawn, may be tested as required but it must be recognized that the grain structure for these conditions may not aztm equiaxed.
If the grain structure is not equiaxed but elongated, then grain size measurements on specimens with different orientations will vary. Automatic image analyzers are affected by these problems to a greater degree than are semiautomatic digitizing tablet measurements.
The computed ASTM grain sizes are 9. A value is converted to an average nearest tenth unit. However, because of the problems satm with counts at the ends of the test lines, this practice is not recommended unless half intercepts or intersections can be tallied separately. 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.
ASTM E — 97 Grain contrast 1 and tint etchants 1,2 are very effective because they generally provide full delineation of the grain structure. Some grain boundaries are e When counting grain boundary intersections, which is usually easier, a tangential intersection with a grain boundary is counted as one intersection.
Automatic Image Analysis L value is converted grain size was found to be For such work, follow the counting rules described in Test Methods E Measure the area of this grain, Amax, by selecting it with a light pen, mouse, or track ball.
With an inverted-type microscope, simply place the specimen face down on the stage plate and hold it in place with the stage clamps. If enlargements are used, the magni? The nature of the heat treatment is usually important, particularly the tempering temperature, if used. The cementite grain boundary? The wstm area, Ati, is then determined by combining the grain boundary and grain interior images, if the number of grains per unit area is to be determined. D are easiest to use.
Avoid an excessively high number of grains per photograph as counting accuracy may be impaired. The grain size measurement methods described in the following paragraphs are those known to produce results with acceptable precision and minimal bias. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below.
Current edition approved Nov. If the grain size varies within the product, specimen and? However, to eliminate grain anisotropy effects non-equiaxed grainseither the image should be rotated using a prism to rotate the live image, or the digitized image can be rotated in memory, or scan lines of several orientations may be used, depending upon the capabilities of the image analyzer used. 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.
Digital correction methods for nonuniform illumination may be used subsequently; however, these methods should not be used in lieu of proper microscope alignment and adjustment. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned e this standard.
The number of whole grains counted per micrograph is Ni. Precision and Bias The grain structure is well revealed but the annealing twins would prohibit use of an automatic image analyzer, but not a digitizing tablet. This standard is subject to revision at any time by the responsible technical ast, and must be reviewed every?
Use of a programmable stage prevents bias in? A data and Eq A1. L is the number of grain boundary intersections per unit length. 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. If measurements were made on only a single plane, for example, the longitudinal plane, report that this was done and the nature of the test method, plus the statistical evaluation of the data. Delete all grains intersecting the test area border from the image so that partial chord lengths within these grains are not measured. Aetm, as with manual application of the Jeffries method, the tablet method also requires marking off of the grains in order to obtain an accurate count.
Anisotropy indexes for the two perpendicular test orientations on the transverse and planar surfaces revealed values of 0. Adjust the stage movement so that the interface between adjacent specimens is avoided, that is, is not in the? Alternatively, determine the degree of enlargement by comparing the size of features on the enlargement to their size on the contact print.
Easily measured using a digitizing tablet and by automatic image analysis after a minor amount of image editing. L value is converted to a lineal 9. Most 10 Related.
ASTM E1382 – 半自動および自動画像解析を用いた平均粒度決定のための標準試験法
Gumi A value is converted to an average nearest tenth unit. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Annex A1 provides information concerning the measurement of grain size and grain anisotropy for non-equiaxed grain structures. All grains intersecting the test area border must be deleted from the image see Table 1. Adjust the stage movement so that the interface e adjacent specimens is avoided, that is, is not in the?
ASTM E1382 - 97(2015)
Dusida Such images exhibit grain contrast or color differences between grains rather than grain boundary delineation. Only the length of the test lines intersecting the grains of interest are measured and the average intercept length and standard deviation are determined as described in paragraphs Such asfm may be employed if the operator can demonstrate their reliability. All grains intersecting the test area border must be deleted from the image see Table 1. For such structures, use the lowest possible magni? Moderate image editing is required. No restrictions except for the diameter of a circular test grid; the number of grains per? Tape the grid corners to the micrograph or tablet surface to prevent movement during measurement.