A STUDY OF THE PREYIELDING MICROSTRAIN IN 3%Si-Fe ALLOY

The preyielding microstrain process in polycrystalline 3%Si-Fe has been investigated with the method of displaying slip bands through electrolytic etching. Three different microstrain stages were found after analysis of the relations between the stress and the percentage of yielding grain and the average number of slip band per yielding grain. Plotted the starting stress at each microstrain stage against the reciprocal square root of grain diameter, three straight lines with different slop were obtained. Consideration of the Hall-Peteh relation, the Brown's microstrain theory and the upper yield point theory, the experimental results were discussed.