Examination of Some Grain Size Measurement Problems


The measurment of grain size is performed nearly always on a metallographically prepared cross section, suitably etched to reveal the grain structure, using methods that pertain only to the grain cross sections. These measurements are termed planar and some may be converted mathematically into spatial estimates of the size of the three-dimensional grains. However, the vast majority of such work is planar where no assumptions about grain shape are required and grain size is described in one- or two-dimensional terms (intercept length, diameter, or area) based on sections through the grains. The most frequently used measurement methods are described in this paper and compared using the same images. These methods are the Jeffries planimetric method, the triple-point count method, and the Hetn intercept method. These methods base grain size on two-dimensional, zero-dimensional, and one-dimensional features
of the microstructure, resnectively (that is areas, points and lines),


The articles and presentations that can be down-loaded from this web site are based upon work done by GFV while employed at Bethlehem Steel (1967-1983), Carpenter Technology (1983-1996), Buehler Ltd. (1996-2009) and Struers (2009-Present) and from the authors consulting work for companies such as, Latrobe Steel, Scot Forge, etc., and from his litigation work. GFV's bylined articles appearing in various issues of the ASM Handbook series have been listed here courtesy of ASM International, Materials Park, Ohio.