ASTM E1268 PDF
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.
|Published (Last):||22 August 2005|
|PDF File Size:||5.75 Mb|
|ePub File Size:||16.3 Mb|
|Price:||Free* [*Free Regsitration Required]|
Each microstructure has been qualitatively described in accordance with the scheme outlined in Fig. Asstm 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.
It is best if the etchant used does not reveal grain boundaries within a given phase. The grid used for these measurements consisted of eight parallel lines, spaced 20 mm 0. The degree of carbon segregation may be estimated by this method and reported for such specimens. However, depending on the alloy or material being examined, other illumination modes, such as polarized light or differential interference contrast illumination, may be used. Precision and Bias The measured means and standard deviations can be easily calculated using most pocket calculators.
ASTM E1268 – 01(2016)
The correlation coefficient is 0. Do not deliberately orient the grid lines over any particular microstructural feature or features.
The appearance of the orientation or banding is inuenced by processing factors such as the solidication rate, the extent of segregation, the degree of hot or cold working, the nature of wstm deformation process used, the heat treatments, and so forth. Calculate the number of interceptions per unit length parallel to the deformation axis, N Lin accordance with: As the degree of orientation or banding increases, the anisotropy index increases above one. The microindentation hardness method may be used for such structures.
A plot of such data on standard rectilinear graph paper reveals two linear portions with a change of slope at 58 HRC 0. This difference requires pattern recognition techniques which are beyond the scope of this method. The above equation is simple to use with a pocket calculator. Precision and Bias Equivalent inch-pound values, when listed, are in parentheses and may be approximate.
Calculate the number of boundary intersections per unit length perpendicular to the deformation atsm, PL’, in accordance with: The microindentation hardness method may be used for such structures. Hardenability studies have demonstrated this relationship for fully martensitic microstructures in steels rapidly quenched from the prescribed austenitizing temperatures.
The Knoop indenter is particularly well suited for this work. N Interceptions—Count the number of individual particles, grains, or patches of the constituent of interest crossed by the grid lines. The mean free path spacing, l’, is calculated in accordance with: 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 and P as 0. The microindentation hardness method may be used for such structures.
Count only phase or constituent boundary intersections between unlike particles, grains, or patches. These test results, however, may not correlate directly with test results on nal product forms. This standard is subject to revision at any time by the responsible technical committee and must be e268 every ve years and if not revised, either reapproved or withdrawn.
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.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
There are presently no absolute guides between the measured quantitative parameters and the qualitative terms used to describe the microstructure. Sampling and Test Specimens 7.
ASTM E (Reapproved ) Ferrite Banding Standard – PDF Free Download
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, e1286 center locations, may also be prepared and tested depending on the nature of the product application. The microindentation hardness test procedure should only be used to determine the difference in hardness in banded heat-treated metals, chiefly steels.
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. The degree of orientation can vary from zero completely random distribution to 1. For as-quenched hardnesses of 58—64 HRC 0. Measurements are made with the test lines parallel and perpendicular to the deformation direction.
The load is adjusted so that the indent can be kept completely within the bands. Measurements are made with the test lines parallel and perpendicular to the deformation direction. For small segregates, it may not be possible to obtain ve or more hardness awtm values.
Both the matrix and the segregates must be fully martensitic except for normal minor amounts of retained austenite and in the as-quenched condition.
The total length of the grid lines should be at least mm. We share information about your activities on the site with our partners and Google partners: Align the specimen so that the deformation direction is horizontal on the projection screen. This specimen was in the as-quenched condition and testing revealed a Knoop microindentation hardness gf of Determine the nature of the banding present, for example, light versus dark etching martensite or bainite versus martensite.
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. Equivalent inch-pound values, when listed, are in parentheses and may be approximate. The accuracy of this conversion will become poorer as the test load decreases below axtm. 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.
However, this degree of uncertainty is not excessive and is less than can be achieved by micro-analytical analysis methods. For isolated particles in a matrix, the number of feature intersections will equal twice the number of feature interceptions. E — 01 Standard Practice for Assessing the Asstm 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 ashm adoption or, in the case of revision, the year of last revision.
Tests should be conducted according to the guidelines given in Test Methods E