| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a bainitic phase structure prediction method with which a bainite fraction is accurately predicted, a block size is predicted and the bainite fraction and the block size can be calculated. <P>SOLUTION: In a bainite transformation calculation step for calculating a bainite fraction and a block size in a steel material of hypo-eutectoid composition cooled from an austenite single-phase temperature or the like with a predetermined cooling pattern, a nucleation of bainitic lath from an austenite grain boundary and a nucleation of bainitic lath from the periphery of nucleated bainitic lath are calculated in a distinguishable manner and the calculation is performed on the assumption that, in the austenite grain boundary or the like that is a nucleation site of bainitic lath, a nucleation enabled area is decreased with the progress of bainite transformation and that a nucleation speed of bainitic lath is varied with increase of distortion energy introduced during bainite transformation caused by increase of carbon content in austenite grains, thereby determining the bainite fraction and the block size. <P>COPYRIGHT: (C)2012,JPO&INPIT |
