Professor Takeo Yokobori, in an amazingly productive career, elucidated essentially all aspects of the fracturing properties of steel and related material behaviors. His research reports, with colleagues and students, have spanned the full range of micro- to macro-structural scales involving test measurements of material stress-strain, cleavage fracturing, fracture mechanics, creep and fatigue behaviors, and analyses of the properties. In the present honoring report, particular attention is given to the influence of polycrystal grain size in determining many of the fracturing properties.
AntolovichS.D. and ArmstrongR.W., Plastic strain localizations in metals: origins and consequences, Prog. Mater. Sci.59 (2013), 1–160.
2.
ArmstrongR.W., The (cleavage) strength of pre-cracked polycrystals, in: Liebowitz H. (ed.), A Special Issue in Honor of Professor Takeo Yokobori on the Occasion of his 70th Birthday Eng. Fract. Mech. 28(5/6): 529–538, 1987.
3.
ArmstrongR.W., Material grain size and crack size influences on cleavage fracturing, in: Armstrong R.W., Antolovich S.D., Griffiths J.R., Knott J.F. (eds), Fracturing Across the Multi-Scales of Diverse Materials Phil. Trans. R. Soc. A 373(2038): 20140124, 2015.
4.
ArmstrongR.W., Dislocation viscoplasticity aspects of material fracturing, Eng. Fract. Mech.77 (2010), 1348–1359.
5.
ArmstrongR.W.BechtoldJ.H. and BegleyR.T., Mechanisms of alloy strengthening in refractory metals, in: TMS-AIME, Metallurgical Society ConferencesSemchyshenM. and PerlmutterI. (eds), vol. 17, Interscience Publishers, NY, 1963, pp. 159–190.
6.
ArmstrongR.W. and RobersonL., Link and G. R. Speich, Analysis of brittle-ductile transition temperature for controlled-rolled, microalloyed, C-Mn based steels, in: Processing Microstructure and Properties of HSLA SteelsDeArdoA.J. (ed.), The Metallurgical Society, AIME, Pittsburgh, PA, 1988, pp. 305–315.
7.
BitzekE. and GumbschP., Mechanisms of dislocation multiplication at crack tips, Acta Mater61 (2013), 1394–1403.
8.
CahnJ. W., Reprise: partial chemical strain dislocations and their role in pinning dislocations to their atmospheres, Phil. Mag.94 (2014), 3170–3176.
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ChakrabartiD.StrangwoodM. and DavisC., Effect of bimodal grain size distribution on scatter in toughness, Metall. Mater. Trans. A40A (2009), 780–795.
10.
CottrellA.H., The yield point in single crystal and polycrystalline steel, in: A symposium on the plastic deformation of crystalline solids, ONR and Carnegie Institute of Technology, Pittsburgh, PA, 1950, pp. 60–74, including discussion.
11.
GudasJ.P.IrwinG.R.ArmstrongR.W. and ZhangX.J., A model for transition fracture of structural steels from observations of isolated cleavage regions, in: Defect Assessment in Components: Fundamentals and ApplicationBlauelJ.G. and SchwalbeK.-H. (eds), Mech. Eng. Publ. Ltd., London, UK, 1991, pp. 549–568.
12.
HirthJ.P., On definitions and assumptions in the dislocation theory for solid solutions, Phil. Mag.94 (2014), 3162–3169.
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IrwinG.R.ZhangX.J. and ArmstrongR.W., Isolated cleavage regions in the ductile fracturing transition of nuclear pressure vessel steels and their weld metals, J. Mater. Sci. Letts.8 (1989), 844–848.
14.
LeslieW.C.SoberR.J.BabcockS.G. and GreenS.J., Plastic flow in binary substitutional alloys of bcc iron: effects of strain rate, temperature and alloy content, Trans. Am. Soc. Met.62 (1969), 690–710.
15.
McMahonC.J. and CohenM., Initiation of cleavage in polycrystalline iron, Acta Metall13 (1965), 591–604.
16.
OgawaK.ZhangX.J.KobayashiT.ArmstrongR.W. and IrwinG.R., Microstructural aspects of the fracture toughness cleavage-fibrous transition for nuclear grade steel, Am. Soc. Test. Mater. STP833 (1984), 393–411.
17.
PetchN.J., The ductile-brittle transition in the fracture of 𝛼-iron, Phil. Mag3 (1958), 1089–1127.
18.
PetchN.J., Theory of the yield point and of strain ageing in steel, in: Advances in Physical Metallurgy, Sir Alan Cottrell’s 70th Birthday MeetingCharlesJ.A. and SmithG.C. (eds), Institute of Metals, London, UK, 1990.
19.
PhillipsW.L. and ArmstrongR.W., The influence of specimen size, polycrystal grain size and yield point behavior on the fatigue strength of low-carbon steel, J. Mech. Phys. Sol.17 (1969), 265–270.
20.
SandströmR. and BergströmY., Relationship between Charpy V transition temperature in mild steel and various material parameters, Met. Sci.18 (1984), 177–186.
21.
SrinivasM.MalakondaiahG.ArmstrongR.W. and Rama RaoP., Ductile fracture toughness of polycrystalline Armco iron of varying grain size, Acta Metall. Mater.39 (1991), 807–816.
22.
SrinivasM.MalakondaiahG. and Rama RaoP., Influence of polycrystal grain size on fracture toughness and fatigue threshold in Armco iron, Eng. Fract. Mech.28 (1987), 561–576.
23.
SuhN.P. and LeeR.S., A dislocation model for the delayed yielding phenomenon, Mater. Sci. Eng.10 (1972), 269–278.
24.
SvobodaJ.ZicklerG.A.KozeschnikE. and FischerF.D., Kinetics of interstitial segregation in Cottrell atmospheres and grain boundaries, Phil. Mag. Lett.95 (2015), 458–465.
25.
WatanabeJ.IwadateT.TanakaY.YokoboriT. and AndoK., Fracture toughness in the transition region, Eng. Fract. Mech.28 (1987), 589–600.
26.
YokoboriT., The Cottrell-Bilby theory of yielding of iron, Phys. Rev.88 (1952), 1423.
27.
YokoboriT., Creep fracture of copper as nucleation process, J. Phys. Soc. Japan7 (1952), 44–47.
28.
YokoboriT., Ductility transition and cold brittleness, J. Phys. Soc. Japan8 (1953), 107–109.
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YokoboriT., Delayed yield and strain rate and temperature dependence of yield point in iron, J. Appl. Phys.25 (1954), 593–594.
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YokoboriT., The theory of fatigue fracture of metals, J. Phys. Soc. Japan10 (1955), 368–374.
31.
YokoboriT., ICF contribution to fracture research in the second half of the 20th century, Int. J. Fract.138 (2006), 37–45.
32.
YokoboriT.IshiiH. and KoyamaS., The effect of ferrite grain size on the cyclic stress-strain response of low carbon steel, Scr. Metall.13 (1979), 515–517.
33.
YokoboriA.T.Jr.IsogaiT. and YokoboriT., A model emitting dislocation group from crack tip with stress singularity and its application to brittle-ductile transition, Acta Metall. Mater.41 (1993), 1405–1411.
34.
YokoboriT. and KameiA., The size of plastic zone at the tip of a crack in plane strain state by the finite element method, Int. J. Fract.9 (1973), 98–100.
35.
YokoboriT.KameiA. and KonosuS., A concept of combined micro and macro fracture mechanics to brittle fracture, Int. J. Fract.10 (1974), 375–377.
36.
YokoboriT.KameiA. and KonosuS., A criterion for low-stress brittle fracture of notched specimens based on combined micro- and macro fracture mechanics-I, Eng. Fract. Mech.8 (1976), 397–409.
37.
YokoboriT. and KonosuS., Effects of ferrite grain size, notch acuity and notch length on brittle fracture stress of notched specimens of low carbon steel, Eng. Fract. Mech.9 (1977), 839–847.
38.
YokoboriT.MaekawaI. and KorekawaS., Effect of ferrite grain size on the fatigue fracture of low carbon steel under combined alternating bending and torsional stresses, Tech. Rep. Tohoku Univ.28 (1963), 65–79.
39.
YokoboriT. and OnishiY., Micro behavior at the notch tip during load increasing in brittle fracture beyond general yield, Int. J. Fract.13 (1977), 751–761.
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YokoboriT.SawakiY. and NakanishiS., Criterion for brittle fracture of notched or cracked specimens based on combined micro- and macro crack mechanics-II, Eng. Fract. Mech.12 (1979), 125–141.
41.
YokoboriA.T.Jr.YokoboriT. and TabuchiM., The master curve and the constitutive equation for creep deformation and fracture for Cr-Mo-V steel throughout smooth, notched and precracked specimens, J. Mater. Sci.31 (1996), 4767–4773.
42.
ZhangX.J.ArmstrongR.W. and IrwinG.R., Stereo (scanning electron microscopy) section fractography of isolated cleavage regions in nuclear vessel steels, Metall. Trans. A20 (1989), 2862–2866.
