1. (a) Employing the intercept technique, determine the average grain size for the steel specimen whose microstructure is shown in Figure 9.25(a); use at least seven straight-line segments.
(b) Estimate the ASTM grain size number for this material.
2. For an ASTM grain size of 6, approximately how many grains would there be per square inch at
(a) a magnification of 100, and
(b) without any magnification?
3. Determine the ASTM grain size number if 30 grains per square inch are measured at a magnification of 250.
4. Determine the ASTM grain size number if 25 grains per square inch are measured at a magnification of 75.