Quantitative investigation into the influence of temperature on carbide and austenite evolution during partitioning of a quenched and partitioned steel

The influence of partitioning temperature on microstructural evolution during quenching and partitioning was investigated in a 0.38C-1.54Mn-1.485i wt.% steel using Mossbauer spectroscopy and transmission electron microscopy. eta-carbide formation occurs in the martensite during the quenching, holding, and partitioning steps. More effective carbon partitioning from martensite to austenite was observed at 450 than 400 degrees C, resulting in lower martensite carbon contents, less carbide formation, and greater retained austenite amounts for short partitioning times. Conversely, greater austenite decomposition occurs at 450 degrees C for longer partitioning times. Cementite forms during austenite decomposition and in the martensite for longer partitioning times at 450 degrees C (C) 2016 Elsevier B.V. All rights reserved.