Analysis of the austenite grain size distribution in plain carbon steels

Abstract

The aim of this paper is to report methods for measuring the austenite grain size in plain carbon steels, including the estimation of the three dimensional grain size distribution. Prior austenite boundaries are revealed using a number of quenching and etching techniques. The grain size is measured by standard manual procedures and by the use of image analysis equipment. Results from these measurement methods are compared and systematic errors are identified. A correction is proposed to account for the systematic error in the measurement of the two dimensional grain size distribution by the use of image analysis. Methods for the estimation of the three dimensional grain size distribution are compared. It is concluded that the method proposed by Matsuura and Itoh is the most versatile.