Nanostructured bainite is extremely resistant to severe tempering making it difficult to reduce its hardness sufficiently to allow certain processing before heat treatment into its final state. An attempt is therefore made to introduce the divorced pearlite reaction that relies on the presence of pro-eutectoid cementite in the austenite in order to produce a microstructure containing spheroidal cementite particles simply by continuous cooling from the two phase austenite and cementite field. It is demonstrated that dramatically reduced hardness values can be achieved using this method.
LyonsJV and HudsonMJ: ‘Machining properties of high-carbon chromium bearing steels’, Technical Report Speical Report 94, Iron and Steel Institute, London, UK, 1967.
2.
BhadeshiaHKDH: ‘Steels for bearings’, Prog. Mater. Sci., 2012, 57, 268–435.
LiSX: ‘Effects of inclusions on very high cycle fatigue properties of high strength steels’, Int. Mater. Rev., 2012, 57, 92–114.
6.
HashimotoK, HiraokaK, KidaK and Costa SantosE: ‘Effect of sulphide inclusions on rolling contact fatigue life of bearing steels’, Mater. Sci. Technol., 2012, 28, 39–43.
7.
WalkerP: ‘Improving the reliability of highly loaded rolling bearings: the effect of up-stream processing on inclusions’, Mater. Sci. Technol., 2014, 30, 385–410.
Garcia-MateoC, PeetM, CaballeroFG and BhadeshiaHKDH: ‘Tempering of a hard mixture of bainitic ferrite and austenite’, Mater. Sci. Technol., 2004, 20, 814–818.
11.
HasanHS, PeetMJ and BhadeshiaHKDH: ‘Severe tempering of bainite generated at low transformation temperatures’, Int. J. Mater. Res., 2012, 103, 1319–1324.
12.
HuF, WuKM, HouTP and ShirzadiAA: ‘Tempering stability of retained austenite in nanostructured dual phase steels’, Mater. Sci. Technol., 2013, 29, 947–953.
BhadeshiaHKDH: ‘Large chunks of very strong steel’, Mater. Sci. Technol., 2005, 21, 1293–1302.
15.
ContractorGP, SchemppEG and MorganWA: ‘Carbide composition and microstructure during the quenching and tempering of a 5CrMoV steel’, Trans. ASM, 1969, 54, 208–219.
16.
KoYG, LeeBW, LeeJS, ChoiDY and ShinDH: ‘Spheroidisation behaviour of 1·0 wt- carbon steel processed by equal channel angular extrusion and annealing’, Mater. Sci. Technol., 2012, 28, 116–119.
17.
KimKH and LeeJS: ‘On the microstructure and properties of Si-modified 100Cr6 bearing steels’, Mater. Sci. Technol., 2012, 28, 50–54.
18.
HondaK and SaitoS: ‘On the formation of spheroidal cementite’, J. Iron Steel Inst., 1920, 102, 261–267.
19.
WhiteleyJH: ‘The formation of globular pearlite’, J. Iron Steel Inst., 1922, 105, 339–357.
20.
UzlovIG, ParusovVV and DolzhenkovII: ‘Mechanism and kinetics of the transformation of austenite to divorced pearlite’, Met. Sci. Heat Treat., 1980, 22, 366–367.
21.
OyamaT, SherbyOD, WadsworthJ and WalserB: ‘Application of the divorced eutectoid transformation to the development of fine-grained, spheroidized structures in ultrahigh carbon steels’, Scr. Metall., 1984, 18, 799–804.
22.
VerhoevenJD and GibsonED: ‘The divorced eutectoid transformation in steel’, Metall. Mater. Trans. A, 1998, 29A, 1181–1189.
23.
VerhoevenJD: ‘The role of the divorced eutectoid transformation in the spheroidization of 52100 steel’, Metall. Mater. Trans. A, 2000, 31A, 2431–2438.
24.
BasabeVV, JonasJJ and GhoshC: ‘Formation of deformation-induced divorced eutectoid pearlite above the Ae1’, Adv. Mater. Res., 2011, 409, 829–834.
25.
PanditAS and BhadeshiaHKDH: ‘Divorced pearlite in steels’, Proc. R. Soc. A, 2012, 468A, 2767–2778.
26.
YinZX and BhadeshiaHKDH: ‘Divorced eutectoid transformation in high Mn bearing steel’, Adv. Mater. Res., 2013, 634–638, 1798–1802.
27.
Al HamdanyA, Al FattalD, JabbarTA and BhadeshiaHKDH: ‘Estimation of the fracture toughness of tempered nanostructured bainite’, Mater. Sci. Technol., 2012, 28, 685–689.
28.
NPL:MTDATA, Software, National Physical Laboratory, Teddington, UK, 2006.
29.
YangH.-S and BhadeshiaHKDH: ‘Uncertainties in the dilatometric determination of the martensite–start temperature’, Mater. Sci. Technol., 2007, 23, 556–560.
30.
HeronLE: ‘Spheroidise annealing of steel tube for bearings’, Metallurgia, 1969, 80, 53–58.
31.
HewittW: ‘The spheroidise annealing of high carbon steel and its effect on subsequent heat treatment’, Heat Treat. Met., 1982, 3, 56–62.
32.
Garcia-MateoC, CaballeroFG, SourmailT, KuntzM, CornideJ, SmanioV and ElviraE: ‘Tensile behaviour of a nanocrystalline bainitic steel containing 3 wt silicon’, Mater. Sci. Eng. A, 2012, A549, 185–192.
33.
HuF, WuKM and ZhengH: ‘Influence of Co and Al on bainitic transformation in super bainitic steels’, Steel Res. Int., 2013, 84, (10), 1060–1065.
