Correlation between Continuous/Discontinuous Yielding and Hall-Petch Slope in High Purity Iron

摘要

High purity iron specimens containing 11 ppm carbon and 8ppm nitrogen with difl'ercnl 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 Hall-Petch slope, k_y, significantly changed depending on the different yielding behaviors.