ASTM E1268 PDF

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.

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The microindentation hardness test procedure should only be used to determine the difference in hardness in banded heat-treated metals, chiey steels.

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. The correlation coefficient is 0. However, this degree of uncertainty is not excessive and is less than can be achieved by micro-analytical analysis methods.

These conversions are for Knoop loads of gf or greater. Calculate the number of feature interceptions per unit length perpendicular to the deformation axis, N L’, in accordance with: Do not deliberately orient the grid lines over any particular microstructural feature or features.

Sampling and Test Specimens 7. A plot of such data on standard rectilinear graph paper reveals two linear portions with a change of slope at 58 HRC 0. This method is applicable only to steels with carbon contents from 0.

All of the measurements were made using 23 enlargements of the photomicrographs presented. Equivalent inch-pound values, when listed, are in parentheses and may be approximate. The test grid is placed over the image projected onto the digitizing tablet and a cursor is used for counting. A minimum of ve measurements in each direction, generally more, were made on each micrograph by one or more persons.

Linear regression for this portion of the conversion reveals the following relationship: Conversion of HK values to HRC or other asrm may involve considerable error particularly for test loads below gf. This requires a measurement of the volume fraction, VV, of the banded or oriented phase constituent by point counting see Practice E or other suitable methods.

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The experimental hardenability data lists an as-quenched hardness of 58 HRC for steels with carbon contents from 0. A superscript epsilon e indicates an editorial change since the last revision or reapproval.

If a test line ends within a particle, count N as 12 and P as 1. Because the degree of banding or asstm may vary through the product cross section, the test plane should sample the entire cross section. A If possible, etch the specimens so that like phase or constituent boundaries are not revealed, only unlike boundaries. Examination at higher magnication may be required to identify and classify the constituents present.

Thi Thiss pra practic cticee ashm covers ers pro proced cedure uress to des describ cribee the appear app earanc ancee of ban banded ded str structu uctures res, pro asym 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 eated ted sp spec ecim imen ens.

The grid used for these measurements consisted of eight parallel lines, spaced 20 mm 0. 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. ASTM D e1. The number and location of such test specimens should be dened by producer-purchaser agreement.

ASTM E 1268 2001(Reapproved 2016) Ferrite Banding Standard

Tangent hits are counted as one half an interception. Link to Active This link will always route to the current Active version of the standard. The microindentation hardness method may be used for such structures. Calculate the number of boundary intersections per unit test length parallel to the deformation axis, PLin accordance with: Conversion of HK values to HRC or other scales may involve considerable error particularly for test loads below gf.

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A If possible, etch the specimens so that like phase or constituent boundaries are not revealed, only unlike boundaries. As the degree of orientation or banding increases, the anisotropy index increases above one.

The length of full cross-section samples, in the deformation direction, should be at least 10 mm 0. The measured means and standard deviations can be easily calculated using most pocket calculators.

Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM E (Reapproved ) Ferrite Banding Standard – PDF Free Download

The degree of orientation ashm vary from zero completely random distribution to 1. The total length of the grid lines should be at least mm. This difference requires pattern recognition techniques which are beyond the scope of this method. Because the degree of banding or orientation may vary through the product cross section, the test plane should sample the entire cross section. The most common example of banding is the layered ferrite-pearlite structure of wrought low-carbon and low-carbon alloy steels.

Hardenability studies have demonstrated this relationship for fully martensitic microstructures in steels rapidly quenched from the prescribed austenitizing temperatures.

This specimen was in the as-quenched condition and testing revealed a Knoop microindentation hardness gf of Precision and Bias It is best if the etchant used does not reveal grain boundaries within a given phase.

Tangent hits aatm counted as one intersection. 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.

Randomly select the initial eld by arbitrarily moving the stage and accepting the new eld without further stage adjustment. The load is adjusted so that the indent can be kept completely within the bands.