Ferrite Grain Refinement by Large Reduction per Pass in Non-recrystallization Temperature Region of Austenite.

Effect of Thermomechanical Controlled Processing on the Microstructure and Mechanical Properties of Fe-C-Mn-Si Multiphase Steels

“…8) Ferrite nucleation occurs not only on austenite grain boundaries but also within grains in the deformed austenite, because the deformation bands and twin boundaries formed during deformation of austenite act as effective ferrite nucleation sites. 9,10) The deformation bands produced by the final reduction in nonrecrystallization temperature region of austenite refine the ferrite grains. Therefore, finer ferrite grains size were obtained in almost all the specimens (Fig.…”

Influence of Accumulated Stress in Austenite on Transformed Ferrite Grain Size by Hot Rolling for a V-microalloyed Steel

“…The inhibition of recrystallisation indicated by T nr appears as a rise in the slope of the MFS curve and in the studied steel is mainly caused by the strain-induced precipitation of vanadium carbonitrides. [3][4][5][6][7][8] This method also offers the possibility of obtaining the A r3 phase transformation temperatures when austenite is being deformed in conditions similar to rolling and the stress accumulated (Ds) in the austenite between T nr and A r3 . 9,10) The accumulated stress in austenite is a direct and precise measurement of the state of austenite as a function of the temperature and can be directly measured without the need to measure the size and lengthening of the austenite grain.…”

Drawing of CCCT diagrams by static deformation and consideration deformation effect on martensite and bainite transformation in NiCrMoV steel

“…Other authors have demonstrated that the type of deformation (tensile, compression, hydrostatic or torsion) (Easterling and Porter, 1992;Bhadeshia, 1992), the amount of strain (Fang et al, 2003;Murr et al, 1982), strain rate (Murr et al, 1982;Luo et al, 2003) in thermomechanical process and prior austenite grain size (Luo et al, 2003) have distinct effects on martensite transformation (MT) and bainite transformation (BT). Also it has been proved that by strain, the nucleation sites of martensite and bainite increase (Murr et al, 1982;Pope, 1972;Nichol et al, 1977;Olson and Cohen, 1975;Koyima et al, 1996;Breedis, 1965). In references, various preferred sites for martensite nucleation (MN) and bainite nucleation (BN) have been introduced (Easterling and Porter, 1992;Forter and Rosenthal, 1959;Suezawa and Cook, 1980).…”