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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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. If the entire test line lies completely within the phase or feature of interest this can occur for parallel counts of a highly banded materialcount N as 12 ast P as 0. N NL 5 L t 2 operator bias. Curren Cur rentt edi editio tion n app approv roved ed Jan Jan.
ASTM E 1268 2001(Reapproved 2016) Ferrite Banding Standard
Current edition approved Dec. However, this degree of uncertainty is not excessive and is less than can be achieved by micro-analytical analysis methods.
The degree of carbon segregation may be asym by this method and reported for such specimens. Both the matrix and the segregates must be fully martensitic except for normal minor amounts of retained austenite and in the as-quenched condition. For fully martensitic carbon and alloy steels 0.
ASTM E (Reapproved ) Ferrite Banding Standard – PDF Free Download
For small segregates, it may not be possible to obtain ve or more hardness tests values. N Interceptions—Count the number of individual particles, grains, or patches of the constituent of interest crossed by the grid lines.
This specimen was in the as-quenched condition and testing revealed a Knoop microindentation hardness gf of NOTE 2—T indicates a tangent hit and E indicates that the grid line ended within the particle; both situations are handled as shown.
NOTE 2—Measurements made on the martensite. Referenc Referenced ed Documents 1. For certain materials, etching may not be necessary as the naturally occurring reectivity differences between the constituents may produce adequate contrast.
If the product form is too large to permit preparation of full cross sections, the samples prepared at the desired locations should have a minimum polished surface area of mm2 0.
Calculation of Results If a line ends within a particle, patch or grain, count it as one half an interception.
The total length of the grid lines should be at least mm. Do not deliberately orient the grid lines over any particular microstructural feature or features. Generally, it is best to count the banded phase present in least amount.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. Each microstructure has been qualitatively described in accordance with the scheme outlined in Fig.
ASTM E1268 – 01(2016)
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Originally published as E — For as-quenched hardnesses of 58—64 HRC 0.
Do not count phase or constituent boundaries between asrm particles, grains, or patches. It is best if the etchant used does not reveal grain boundaries within a given phase.
The experimental hardenability data lists an as-quenched hardness of 58 HRC for steels with carbon contents from 0. Precision and Bias 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. Tangent hits are counted as one half an interception.
The grid used for these measurements consisted of eight parallel lines, spaced 20 mm 0. Linear regression for this portion of the conversion reveals the e12268 relationship: Other examples of banding include carbide banding in hypereutectoid tool steels and martensite banding in heat-treated alloy steels.
Calculate the number of boundary intersections per unit test length parallel e1628 the deformation axis, PLin accordance ast, Banding or orientation is asgm observed using low magnications, for example, to Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. The test grid is placed over the image projected onto the digitizing tablet and a cursor is used for counting.
This difference requires pattern recognition techniques which are beyond the scope of this method. Decide which phase astk constituent is banded. Last previous edition approved e12668 as E — 01 Solid-state transformations may be inuenced by the resulting microsegregation pattern leading to development of a layered or banded microstructure. This problem occurs most commonly in NL and 1e268 measurements in highly banded structures.
E — 01 Standard Practice for Assessing the Degree of Banding or Orientation of Microstructures1 This standard is issued under the xed designation E ; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. 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 astn in hardness between bands in heat trea tr eated ted sp spec ecim imen ens.
These conversions are for Knoop loads of gf or greater. Calculate the number of boundary intersections per unit length perpendicular to the deformation axis, PL’, in accordance with: The deformation axis in each microstructure shown is horizontal.