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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Do not count phase or constituent boundaries between like particles, grains, or patches. N Interceptions—Count the number of individual particles, grains, or patches of the constituent of interest crossed by the grid asm.
Stereological methods are not suitable for measuring individual features, instead use standard measurement procedures to dene the feature size. Generally, it is best to count the banded phase present in least amount. The correlation coefficient is 0. The experimental hardenability data lists an as-quenched hardness of 58 HRC for steels with carbon contents from 0. Banding or orientation is best observed using low magnications, for example, to For isolated particles in a matrix, the number of feature intersections will equal twice the number of feature interceptions.
Remember me Forgot password? Precision and Bias The preparation procedure must reveal the microstructure without excessive inuence from preparation-induced deformation or smearing.
The aetm of orientation can vary from zero completely random distribution to 1. For small segregates, it may not be possible to obtain ve or more hardness tests values. Thi Thiss pra practic cticee cov covers ers pro proced cedure uress to des describ cribee the appear app earanc ancee of ban banded ded str structu uctures res, pro proced cedure uress for cha charac racter terizin izing g the ext extent ent of ban bandin ding, g, and a microindentation hardness procedure for determining the difference in hardness between bands in heat trea tr e126 ted sp sstm ecim imen ens.
Stereological methods are not suitable for measuring individual features, instead use standard measurement procedures to define the feature size. When a test line is tangent to the particle, grain, or patch of interest, N is counted as 12and P as 1. Calculate the number of interceptions per unit length parallel to the deformation axis, N Lin accordance with: The microindentation hardness method may be used for such structures.
Summary of Practice 4. The grid used for these measurements consisted of eight parallel lines, spaced 20 mm 0. Do not deliberately orient the grid lines over any particular microstructural feature or features.
Decide which phase or constituent is banded. Alternatively, both phases may be aligned with neither appearing as a matrix phase.
Sco Scope pe 1. For P intersections, do not count phase or constituent boundaries between like particles, grains, etc.
Either NL or PL, or both see The degree of carbon segregation may be estimated by this method and reported for such specimens. Conversion of HK values to HRC or other scales may involve considerable error particularly for test loads below gf. This problem occurs most commonly in NL and E12688 measurements in highly banded structures.
The grid should be placed without operator bias. Randomly select the initial eld by arbitrarily moving the stage and accepting the new eld without further stage adjustment. A number in parentheses indicates the year of last reapproval.
Next, depending on the measurements performed, list the anisotropy index or indexesAI, calculated in Etching must produce strong contrast between the phases or constituents of interest. 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.
If the banded condition appears to vary substantially across the longitudinal section, measurements may be made at specic locations, for example, subsurface, midthickness and center locations, or at a series of locations across the thickness to assess the positional variability. For a two-phase structure, count all of the interceptions of the phase of interest, that is, those that are clearly part of the bands and those that are not.
The above equation is simple to use with a pocket calculator. P’ PL’ 5 L t 3 where: The appearance of the orientation or banding is influenced by processing factors such as the solidification rate, the extent of segregation, the degree of hot or cold working, the nature of the deformation process used, the aatm treatments, and so forth. Individual reprints single or multiple copies of this standard may be ast, by contacting ASTM at the above address or at phonefaxor service astm.