The bainite transformation in a low-carbon Si-containing steel has been studied in situ by synchrotron X-rays. While the austenite is homogeneous prior to transformation, the carbon distribution becomes nonuniform as bainite plates form. This is because of the different degrees of physical isolation of films and blocks of residual austenite. The method for converting dilatational strain into bainite volume fraction, using lattice strain as a reference, during isothermal transformation was found to overestimate it. The bainitic and martensitic ferrite did not exhibit a tetragonal unit cell due to the low-carbon content of the steel and the high transformation temperature.
BhadeshiaHKDH.Novel steels for rails. In: Buschow K, Cahn RW, Flemings MC, Iischner B, Kramer EJ, Mahajan S, editors. Encyclopedia of Materials Science: Science and Technology. Oxford: Pergamon Press, Elsevier Science; 2002, p. 1–7.
2.
ChangLC.The rolling/sliding wear performance of high silicon carbide-free bainitic steels. Wear. 2005;258:730–743. doi: 10.1016/j.wear.2004.09.064
3.
ZhangFC, ZhangCL, LvB, et al. Effects of hydrogen on the properties of bainitic steel crossing. Eng Failure Anal. 2009;16:1461–1467. doi: 10.1016/j.engfailanal.2008.09.019
4.
LiY, ZhangF, ChenC, et al. Effects of deformation on the microstructures and mechanical properties of carbide–free bainitic steel for railway crossing and its hydrogen embrittlement characteristics. Mater Sci Eng A. 2016;651:945–950. doi: 10.1016/j.msea.2015.09.117
5.
BhadeshiaHKDH.Bainite in steels: theory and practice. 3rd ed. Leeds: Maney Publishing; 2015.
6.
CaballeroFG, BhadeshiaHKDH, MawellaKJA, et al. Very strong low temperature bainite. Mater Sci Technol. 2002;18:279–284. doi: 10.1179/026708301225000725
7.
Garcia-MateoC, CaballeroFG, BhadeshiaHKDH.Development of hard bainite. Iron Steel Instit Japan Int. 2003;43(8):1238–1243. doi: 10.2355/isijinternational.43.1238
8.
CaballeroFG, MillerMK, BabuSS, et al. Atomic scale observations of bainite transformation in a high carbon high silicon steel. Acta Mater. 2007;55:381–390. doi: 10.1016/j.actamat.2006.08.033
9.
Hulme-SmithCN, LonardelliI, DippelAC, et al. Experimental evidence for non-cubic bainitic ferrite. Scr Mater. 2013;69:409–412. doi: 10.1016/j.scriptamat.2013.05.035
10.
JangJH, BhadeshiaHKDH, SuhDW.Solubility of carbon in tetragonal ferrite in equilibrium with austenite. Scr Mater. 2013;68:195–198. doi: 10.1016/j.scriptamat.2012.10.017
11.
BhadeshiaHKDH.Carbon in cubic and tetragonal ferrite. Philos Mag. 2013;93:3714–3725. doi: 10.1080/14786435.2013.775518
12.
Hulme-SmithCN, PeetMJ, LonardelliI, et al. Further evidence of tetragonality in bainitic ferrite. Mater Sci Technol. 2015;31:254–256. doi: 10.1179/1743284714Y.0000000691
13.
HammersleyAP.FIT2D: an introduction and overview. European Synchrotron Radiation Facility Internal Report ESRF97HA02T, 68, 1997.
14.
RietveldHM.A profile refinement method for nuclear and magnetic structures. J Appl Crystallogr. 1969;2:65–71. doi: 10.1107/S0021889869006558
15.
LutterottiL, MatthiesS, WenkHR.MAUD: a friendly java program for material analysis using diffraction. IUCr: Newsletter of the CPD, 21, 1999.
16.
TobyBH.R factors in rietveld analysis: how good is good enough? Powder Diffr. 2006;21:67–70. doi: 10.1154/1.2179804
17.
DysonDJ, HolmesB.Effect of alloying additions on the lattice parameter of austenite. J Iron Steel Res, Int. 1970;208:469–474.
18.
BhadeshiaHKDH, DavidSA, VitekJM, et al. Stress induced transformation to bainite in Fe-Cr-Mo-C pressure vessel steel. Mater Sci Technol. 1991;7:686–698. doi: 10.1179/mst.1991.7.8.686
19.
BabuSS, SpechtED, DavidSA, et al. In-situ observations of lattice parameter fluctuations in austenite and transformation to bainite. Metallur Mater Trans A. 2005;36:3281–3289. doi: 10.1007/s11661-005-0002-x
20.
HondaE, NishiyamaZ.On the nature of the tetragonal and cubic martensites. Sci Rep Tohoku Imperial Univ. 1932;21:299–331.
21.
ChristianJW.Tetragonal martensites in ferrous alloys – a critique. Mater Trans, JIM. 1992;33:208–214. doi: 10.2320/matertrans1989.33.208
22.
BhadeshiaHKDH.Bainite: overall transformation kinetics. Le J de Phys Colloques. 1982;43:C4–443.
StoneHJ, PeetMJ, BhadeshiaHKDH, et al. Synchrotron X-ray studies of austenite and bainitic ferrite. Proc R Soc London A: Math, Phys Eng Sci. 2008;464:1009–1027. doi: 10.1098/rspa.2007.0201
25.
XiongXC, ChenB, HuangMX, et al. The effect of morphology on the stability of retained austenite in a quenched and partitioned steel. Scr Mater. 2013;68:321–324. doi: 10.1016/j.scriptamat.2012.11.003
26.
YangHS, BhadeshiaHKDH.Austenite grain size and the martensite-start temperature. Scr Mater. 2009;60:493–495. doi: 10.1016/j.scriptamat.2008.11.043
27.
BlondéR, Jimenez-MeleroE, ZhaoL, et al. High-energy X-ray diffraction study on the temperature-dependent mechanical stability of retained austenite in low-alloyed TRIP steels. Acta Mater. 2012;60:565–577. doi: 10.1016/j.actamat.2011.10.019
28.
CaballeroFG, MillerMK, MateoCG, et al. Redistribution of alloying elements during tempering of a nanocrystalline steel. Acta Mater. 2008;56:188–199. doi: 10.1016/j.actamat.2007.09.018
29.
CaballeroFG, MillerMK, ClarkeAJ, et al. Examination of carbon partitioning into austenite during tempering of bainite. Scr Mater. 2010;63:442–445. doi: 10.1016/j.scriptamat.2010.04.049
30.
PodderAS, LonardelliI, MolinariA, et al. Thermal stability of retained austenite in bainitic steel: an in situ study. Proc R Soc A. 2011;467:3141–3156. doi: 10.1098/rspa.2011.0212
31.
GongW, TomotaY, HarjoS, et al. Effect of prior martensite on bainite transformation in nanobainite steel. Acta Mater. 2015;85:243–249. doi: 10.1016/j.actamat.2014.11.029
32.
BhadeshiaHKDH, EdmondsDV.The bainite transformation in a silicon steel. Metallur Trans A. 1979;10:895–907. doi: 10.1007/BF02658309
33.
KozeschnikE, BuchmayrB.MATCALC – a simulation tool for multicomponent thermodynamics, diffusion and phase transformations. Fifth International Seminar on the Numerical Analysis of Weldability; 1999. p. 349–361.
34.
ZenerC.Kinetics of the decomposition of austenite. Trans Metallur Soc AIME. 1946;167:550–595.
