Effect of deformation of austenite and cooling rates on transformation microstructures in a Mn–Cr gear steel

Phase transformations in a simulated hot stamping process of the boron bearing steel

“…The same result was indicated by Wang et al [31] in another study on Mn-Cr gear steel. The disagreement might refer to variation of alloying element between these steels and 22MnB5 steel.…”

“…By deformation, the critical cooling rate to martensite transformation, (the cooling rate that leads to a fully martensitic microstructure) was increased from 30°C/s to 60°C/s as reported by Nikravesh et al [24]. Wang et al [31] have also shown an increase in the critical cooling rate due to deformation of austenite in Mn-Cr gear steel. But the amount of increase depends on the amount of deformation and other process parameters.…”

Effect of Finish Rolling Temperature on the Microstructure and Tensile Properties of Nb–Ti Microalloyed X90 Pipeline Steel

“…It is confirmed that the transformed microstructures all consist of quasi-polygonal ferrite (QF) and granular bainitic ferrite (GF) with dispersed islands of secondary phases (mainly M/A constituent) in the ferrite matrix. Based on the researches by Xiao et al [16][17][18], this complicated intermediate transformation microstructure is defined as acicular ferrite (AF). The corresponding microstructure phases have been marked in the SEM micrographs of this study ( Figure 6).…”

“…However, a kind of ferrite that could nucleate in the dislocation substructure of TMCP-processed steel during accelerated continuous cooling, according to [14,15], and grow into the irregular plates, is also defined as acicular ferrite (AF). Furthermore, considering the diverse morphologies of this AF, some investigators [16][17][18] have proposed that the microstructure of AF is consisting of quasi-polygonal ferrite (QF), granular bainitic ferrite (GF) and even a little bainite ferrite (BF) with dispersed islands of martensite/austenite (M/A) in the matrix. The works by Kang et al [19] and Sung et al [20] indicated that with the decreasing finish rolling temperature, both strength and toughness were significantly improved on account of the grain refinement.…”

Bainite transformation affected by predeformation and stress in G55SiMoV steel

“…[1][2][3] The accumulated strain and stress in the deformed austenite should have a great effect on the subsequent bainite transformation, i.e., the state of austenite was one of the main factors on the transformation. Therefore, the related researches have been studied.…”