Automated image analysis software for assessing banding or orientation of Microstructures in dual phase steel. For Annual Book of ASTM approved in Last previous edition approved in as E – 01(). Standards volume information, refer to the standard’s . ASTM E_ – Designation: E – 01 Standard Practice for Assessing the Degree of Bandin.
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Historical Version s – view previous versions of standard. Calculate the number ee1268 boundary intersections per unit test length parallel to the deformation axis, PLin accordance with: The degree of carbon segregation may be estimated by this method and reported for such specimens.
Precision and Bias A superscript epsilon e indicates an editorial change since the last revision or reapproval. Astj of Practice 4. The microindentation hardness test procedure should only be used to determine the difference in hardness in banded heat-treated metals, chiefly steels. Determine the nature of the banding present, for example, light versus dark etching martensite or bainite versus martensite.
Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.
This standard is subject to revision at any time by the e12688 technical committee and must be reviewed every ve years and if not revised, either reapproved or withdrawn. The grid was alternately qstm perpendicular and parallel asm the deformation axis at various locations over the prints, selected at random with as little bias as possible.
For certain materials, etching may not be necessary as the naturally occurring reectivity differences between the constituents may produce adequate contrast. Tangent hits are counted as one half an interception. 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.
Conversion of HK values to HRC or e12268 scales may involve considerable error particularly for test loads below gf. NOTE 2—Measurements made on the carbides. Equivalent inch-pound values, when listed, are in parentheses and may be approximate. Determine the nature of the banding present, for example, light versus dark etching martensite or bainite versus martensite.
Do not deliberately orient the grid lines over any particular microstructural feature or features.
Tangent hits are counted as one intersection. However, this degree of uncertainty is not excessive and is less than can be achieved by micro-analytical analysis methods. The Knoop indenter is particularly well suited for this work. The anisotropy index for a randomly oriented, non-banded microstructure is one. The relative accuracy of test measurements parallel to the hotworking axis is nearly always poorer than for measurements perpendicular to the deformation direction, as demonstrated by the test data in Annex A1.
Both the matrix and the segregates must be fully martensitic except for normal minor amounts of retained austenite and in the as-quenched condition. This method is applicable only to steels with carbon contents from 0. Signicance and Use 5. For small segregates, it may not be possible to obtain ve or more hardness tests values.
The measured means and standard deviations can be easily calculated using most pocket calculators. Because the degree of banding or orientation may vary through the product cross section, the test plane should sample the entire cross section.
Equivalent inch-pound values, when listed, are in parentheses and may be approximate. Table 1 provides rules for counting while Fig.
For plate or sheet products, a planar oriented that is, polished surface parallel to w1268 surface of the plate or sheet test specimen, at subsurface, mid-thickness, or center locations, may also be prepared and tested depending on the nature of the product application. A minimum of ve measurements in each direction, generally more, were made on each micrograph by one or more persons.
The grid used xstm these measurements consisted of eight parallel lines, spaced 20 mm 0. The grid should be placed without operator bias. The experimental hardenability data lists an as-quenched hardness of 58 HRC for steels with carbon contents from 0.
Calculate aatm number of interceptions per unit length parallel to the deformation axis, N Lin accordance with: The degree of orientation can vary from zero completely random distribution to 1.
If possible, a gf load should be used, particularly if the equivalent Rockwell C hardness HRC is to be estimated. For plate or sheet products, a planar oriented that is, polished surface parallel to the surface of the plate or sheet test specimen, at subsurface, mid-thickness, or center locations, may also be prepared and tested depending on the nature of the product application.
Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. The mean free path spacing, l’, is calculated in accordance with: Test Methods E list appropriate etchants for most metals and alloys. If the section size is too large to permit full cross sectioning, samples should be taken at standard locations, for example, subsurface, mid-radius or quarter-pointand center, or at specic locations based upon producer-purchaser agreements.
The magnication must be high enough to permit accurate counting of feature interceptions or phase boundary intersections. Remember me Forgot password? The equations given in Annex A2 may be helpful for such conversions.