Astm E562-19e1 New! Jun 2026

Dual-phase (DP) and complex-phase steels require exact volume fractions of hard martensite islands embedded in a soft ferrite matrix to optimize crash energy absorption.

ASTM E562-19e1 provides a structured framework for conducting systematic reviews. The key elements of this standard practice include:

) 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.

) is the sum of the full points plus half the boundary points. 5. Statistical Calculations and Formulae

In the early days of metallurgy, engineers guessed. They looked at a grainy black-and-white photo through a microscope and said, "Looks like about 10% impurities." That guess cost lives. The industry needed a standard, a mathematical sword to cut through the subjectivity. astm e562-19e1

PP,i=PiPTcap P sub cap P comma i end-sub equals the fraction with numerator cap P sub i and denominator cap P sub cap T end-fraction Picap P sub i is the number of points hitting the phase in field PTcap P sub cap T is the total number of points on the grid. The mean point fraction ( P̄Pcap P bar sub cap P ) across all fields examined is:

The process involves a systematic manual count and can be summarized in the following steps:

Analysis: In this example, the 95% Confidence Interval is quite wide (13.44%), and the Relative Accuracy (

VV=AA=PP=PiPTcap V sub cap V equals cap A sub cap A equals cap P sub cap P equals the fraction with numerator cap P sub i and denominator cap P sub cap T end-fraction Picap P sub i ) is the sum of the full points

= (the 2D area of the phase divided by the total polished area). PPcap P sub cap P

Vega’s jaw tightened. “How do you know?”

: If two phases have similar colors, software may fail to distinguish them, whereas a trained human eye can. Calibration

The standard didn't just give him a number; it gave him the correlation. According to the appendix of E562, a volume fraction that high drastically reduces fatigue life. Aris looked at the charts. He traced the line. It pointed exactly to the number of cycles the turbine had survived before exploding. They looked at a grainy black-and-white photo through

Another standard, ASTM E45, is specifically for determining the of steel. While it uses manual point counting, its application is specialized for non-metallic inclusions.

The operator examines several randomly selected fields of view (FOV). A grid is overlaid on each image, and the operator determines whether each point falls entirely within the phase of interest, partially inside it, or completely outside. Points that lie exactly on the boundary of the phase are typically counted as half. 4. Statistical Analysis

The user places a digital or physical transparent grid over the viewing field. Square grids of (9 points), (16 points), or (25 points) are standard.

Before diving into the test method, it's essential to understand some key concepts and definitions: