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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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 mean free path spacing, l’, is calculated in accordance with: Etching must produce strong contrast between the phases or constituents of interest. 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.
The grid used for these measurements consisted of eight parallel lines, spaced 20 mm 0.
ASTM E (Reapproved ) Ferrite Banding Standard – PDF Free Download
Equivalent inch-pound values, when listed, are in parentheses and may be approximate. Randomly select the initial eld by arbitrarily moving the stage and accepting the new eld without further stage adjustment. The degree of orientation can vary from zero completely random distribution to 1. The grid was alternately aligned perpendicular and parallel to the deformation axis at various locations over the prints, selected at random with as little bias as possible.
There are presently no absolute guides between the measured quantitative parameters and the qualitative terms used to describe the microstructure. Do not count phase or constituent boundaries between like particles, grains, or patches. We share information about your activities on the site with our partners and Google partners: Referenc Referenced ed Documents 1. The accuracy of this conversion will become poorer as the test load decreases below gf. The Knoop microindentation hardnesses gf for matrix and segregate are converted to HRC values Eq 1 and Eq 3 of Annex A2 and the carbon contents are estimated using Eq 2 or Eq 4 Annex A2depending on the hardness level.
Each microstructure has been qualitatively described in accordance with the scheme outlined in Fig. Equ Equiva ivalen lentt inc inch-p h-poun ound d val values ues, whe when n listed, are in parentheses and may be approximate. The Knoop indenter is particularly well suited for this work. Tangent hits are counted as one intersection. The microindentation hardness method may be used for such structures. Pub Publis lished hed Apr April il However, this degree of uncertainty is not excessive and is less than can be achieved by micro-analytical analysis methods.
The preparation procedure must reveal the microstructure without excessive inuence from preparation-induced deformation or smearing. P’ PL’ 5 L t 3 where: However, an experienced operator can distinguish between the two forms of alignment, perhaps aided by the examples in Annex A1.
ASTM E1268 – 01(2016)
For small segregates, it may not be possible to obtain ve or more hardness tests values. This method is applicable only to steels with carbon contents from 0. The experimental hardenability data lists an as-quenched hardness of 58 HRC for steels with carbon contents from 0. The number and location ee1268 such test specimens should be dened by producer-purchaser agreement.
Other examples of banding include carbide banding in hypereutectoid tool steels and martensite banding in heat-treated alloy steels. The grid should be placed without operator bias. Ne12688 the test lines in the same way as described in This problem occurs most commonly in NL and PL measurements in highly banded structures. If both phases or constituents are banded, with no obvious matrix phase, choose one of the phases e11268 for counting.
Table 1 provides rules for counting while Fig. Examination at e11268 magnication may be required to identify and classify the constituents present.
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. The magnication must be high enough to permit accurate counting of feature interceptions or phase boundary intersections. Tangent hits are counted as one half an interception. Current edition approved Dec.
If a test line ends within a particle, count N as 1e268 and P as 1.
ASTM E 1268 2001(Reapproved 2016) Ferrite Banding Standard
Sco Scope pe 1. Tangent hits are counted as one half an aetm. 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 equations given in Annex A2 may be helpful for such conversions. Linear regression for this portion of the conversion reveals the following relationship: Th Thee st ster ereo eolo logi gica call me meth thod odss ma may y als also o be us used ed to ch char aract acter erize ize no nonn-ba band nded ed microst micr ostruc ructur tures es with seco second nd pha phase se con constit stituen uents ts ori oriente ented d elo elonga ngated ted in var varyin ying g deg degree reess in the deformation direction.
Etching must produce strong contrast between the phases or constituents of interest. These conversions are for Knoop loads of gf or greater.
Solid-state transformations may be inuenced by the resulting microsegregation pattern leading to development of a layered or banded microstructure. The microindentation hardness test procedure should only be used to determine the difference in hardness in banded heat-treated metals, chiefly steels.
Thus, there is a narrow range of uncertainty in predicting the carbon content, particularly for carbon contents of 0.