A new electronic grain-size analyser for technical steel

A new nondestructive method for grain-size analysis of ferromagnetic materials is described. The method is based on the measurement of the statistical behaviour of transitions in the ferromagnetic domains. A correlation is shown to exist between these transitions and the optically perceptible grain-size distribution of the material. The measuring apparatus is discussed in detail, accompanied by the results of experimental measurements. The instrument seems to be capable of estimating the relative grain-size distribution of technical steel with a differential accuracy greater than 0.5 degrees ASTM. The method can be used in industrial environments for the on-line measurement of steel quality, thus eliminating some of the common problems of optical grain-size analysis.