Probability density of stacking faults in austenite under continuous heating and cooling

High-speed x-ray photography permits a quantitative assessment of the probability density α of stacking faults in austenite. The determination of α using high-speed x-ray photography is peculiar in that the same sample serves as the test and reference material during heating and cooling. Changes in the relative position of the (111) and (311) line angles rather than their absolute values are measured. The method permits a quantitative assessment of the probability density α of stacking faults in austenite during phase transformations under continuous heating and cooling of pure iron and steels 30 and U8 in annealed, deformed, and tempered states. The formation and disintegration of austenite in iron and steel involves broadening and relative shift of the (311) and (111) lines.