標準號：IS 4748-1968
發布日期：1969/8/1 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：1.1 This standard covers methods for determining the average grain size of metals and alloys consisting entirely or principally of a single phase. It is also applicable to light to moderately worked metals and alloys and materials having structures similar to metallic structures and comparable to those given in Fig. 1 to 3 ( kept separately ).1.2 In multi-phase alloys, the grain size of the matrix alone shall be determined except that in cases when the other phases are of sufficient amount, size or significance, their grain sizes also shall be separately reported by using comparison method.1.3 Evaluating the grain size of heavily cold-worked or partially recrystallized materials as well as the determination of macro grain size is not covered in this standard.1.4 Four methods of determination of grain size have been stipulated, namely:a) Comparison method;b) Planimetric ( or Jeffries ) method;c) Intercept ( or Heyn ) method; andd) Intercept, open scale ( Snyder & Graff) method.1.5 The comparison method is very convenient and sufficiently accurate for most routine purposes. For higher degrees of accuracy, the planimetric or the intercept method may be used.1.6 In case of dispute, the planimetric method shall be the referee method for equiaxed grains and the intercept method shall be the referee method for material with non-equiaxed grains.1.7 To assist in conversions among various grain size units a few simple formulas have been included in Appendix A.