Correlation between continuous/discontinuous yielding and hallpetch slope in high purity iron

Abstract

High purity iron specimens containing 11 ppm carbon and 8 ppm nitrogen with different grain sizes were fabricated by cold rolling and subsequent annealing. It was found that the specimens exhibited entirely different yielding behavior in tensile tests depending on different cooling processes after annealing. The water-cooled specimens exhibited continuous yielding while the air-cooled ones exhibited discontinuous yielding. It was found that the HallPetch slope, ky, significantly changed depending on the different yielding behaviors. © 2013 The Japan Institute of Metals and Materials.