Astm E562-19e1 【480p】
To avoid human bias, fields of view must be chosen systematically, not selectively. This is usually achieved by moving the microscope stage by a fixed distance (e.g., every 2 mm) in an X-Y matrix across the specimen surface. 4. Counting Rules
If the grid intersection falls directly on the boundary line between the phase of interest and the matrix.
The analyst uses a point-counting grid, which is available in several forms. It can be a grid pattern printed on a transparent sheet that can be placed over a printed micrograph or projected onto a live microscope image using a camera lucida. Alternatively, analysts can use a graticule or reticule (a small, calibrated glass disc) placed inside the microscope's eyepiece. The standard does not mandate a specific grid design; any grid with an array of points is acceptable as long as it is used systematically.
RA=(95% CIP̄)×100cap R cap A equals open paren the fraction with numerator 95 % CI and denominator cap P bar end-fraction close paren cross 100 The standard typically targets an RAcap R cap A of 10% to 20% depending on the application requirements. Industrial Applications of ASTM E562-19e1
: Used to measure precise volume fractions of martensite, ferrite, and bainite within complex Heat-Affected Zones (HAZ) of automotive resistance spot welds. astm e562-19e1
) that fall directly on the target phase. Points falling on boundaries are counted as 12one-half Step 6: Calculation
Once data from all fields are collected, calculate the average volume fraction and the statistical confidence intervals. 1. Mean Volume Fraction ( V̄Vcap V bar sub cap V
: Used to view the polished and etched specimen.
ASTM E562-19e1 is not just about counting; it requires a statistical evaluation of the precision of the result. To avoid human bias, fields of view must
ASTM E562 remains the primary referee method used to calibrate automated software systems or resolve disputes regarding material specifications. Key Applications in Metallurgy
$$Vf = \fracP_cP_t$$
The test grid consists of a series of intersecting straight lines. The points of intersection form the test locations. Common grid configurations include symmetric square matrix arrays such as: ( 25-point grids ( 49-point grids ( 100-point grids ( The Boundary Counting Rules
Extremely Fast; processes dozens of fields of view within seconds. Counting Rules If the grid intersection falls directly
: The year of the last major technical approval or revision (2019).
While automatic image analysis is common, ASTM E562 remains critical in several scenarios.
Chemical or electrolytic etchants must be applied to reveal distinct boundary lines between the constituent phases. For instance, Nital is preferred for dual-phase steels, while Beraha's or Murakami's reagents are used to differentiate phases in duplex stainless steels.
) of an overlay grid intersecting a secondary phase is an unbiased estimator of the area fraction ( AAcap A sub cap A ) and, consequently, the overall volume fraction ( VVcap V sub cap V ) of that phase within the bulk material.
ASTM E562-19e1 is a powerful, detailed, and flexible standard for characterizing materials. By providing a systematic and statistically sound method for manual point counting, it empowers metallurgists, materials scientists, and quality control engineers to obtain reliable volume fraction data across a wide range of materials and applications. Whether used as a primary tool or a complementary technique to automated analysis, it remains a cornerstone of modern quantitative metallography.