Microstructural characterization of TRIP-aided steels

Cold rolled steel sheets containing 0.4C, 0.5Si, 1.5Mn, 1.0Al, 0.02Nb and 0.1Mo (mass%) were subjected to three heat treatment schedules to produce TRIP-aided steels with annealed martensite (AM), bainitic ferrite (BF) and polygonal ferrite (PF) matrix microstructures. The distribution of different phases in these three varieties of steels was estimated using some existing quantitative relationships. In most of the cases, distribution of different constituents of the microstructure and the partitioning of carbon among the different phases could be estimated.