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Wear 269 (2010) 647–654

Contents lists available at ScienceDirect

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olling contact fatigue of Hadfield steel X120Mn12

. Harzallaha,b,∗, A. Mouftiezb, E. Feldera, S. Haririb, J.-P. Maujeanc

Cemef, UMR CNRS/Mines ParisTech 7635, BP 207, 06904 Sophia Antipolis Cedex, FranceTPCIM, Ecole des Mines de Douai, 941 rue Charles Bourseul, BP 10838, 59508 Douai Cedex, FranceOutreau Technologies, R&D, BP 119, 62230 Outreau, France

r t i c l e i n f o

rticle history:eceived 27 January 2010eceived in revised form 2 July 2010ccepted 5 July 2010vailable online 14 July 2010

a b s t r a c t

Hadfield steel is well known for its high work hardening capacity and wear resistance. The alloyX120Mn12 is specifically used in railroad castings such as frogs and crossings in west European countriessuch as France. The influence of various contact parameters on the mechanical behaviour of this alloywas investigated by rolling contact tests. The results are described and discussed using micro-hardnessmeasurements, optical and scanning electronic microscopy and EBSD analyses.

eywords:adfield steelolling contactardnessork hardening

© 2010 Elsevier B.V. All rights reserved.

icrostructureolling fatigue

. Introduction

Austenitic manganese steels have been known for more thanne century. A. Pourcel improved and perfected the manufactur-ng process, but they are named after R.A. Hadfield who undertook

very detailed study on these alloys since 1878 [1]. These steelsre known for their exceptional work hardening capacity underuch loadings as repetitive impact or friction. Their behaviour is nothat simple. In fact, they are initially neither soft nor hard [2], theyre very susceptible to segregation phenomena and they have anustenitic � (Face Centred Cubic) structure only after water quench-ng like low carbon austenitic stainless steels such as X10CrNi18-8AISI 301). Tofaute and Linden [1] demonstrated that the Hadfieldteel can achieve an austenitic structure at room temperature whents chemical composition is such that

neq = (%Mn) + 13(%C) ≥ 17 (1)

The good castability of alloy X120Mn12 makes it a good can-

idate for the production of very large foundry parts. This alloy

s specifically employed for the casting of railway crossings. Plasticeformation of austenitic steels is generally provided by dislocationisplacement. Other deformation mechanisms have been observed

∗ Corresponding author at: CEMEF, UMR CNRS/Mines ParisTech 7635, BP 207,6904 Sophia Antipolis Cedex, France. Tel.: +33 03 27 71 23 13;ax: +33 03 27 71 29 18.

E-mail address: ridha.harzallah@mines-paristech.fr (R. Harzallah).

043-1648/$ – see front matter © 2010 Elsevier B.V. All rights reserved.oi:10.1016/j.wear.2010.07.001

to occur in austenitic Fe–Mn–C steel [3–10], as it is the case in someaustenitic stainless steel. These mechanisms are in competitionwith dislocation displacement and induce excellent mechanicalproperty. They are twinning and martensitic transformation.

The structure of Hadfield steel can become fully austenitic aftersolutioning followed by water quenching. In this condition, theHadfield steel is scarcely ever used in friction since it is known thataustenite has a low wear resistance. It has however been reportedthat some working conditions may favour hardening of austeniteunder friction loading. Hadfield steel can then acquire an excellentwear resistance after some time, but this can only be obtained aftera certain amount of wear, which restricts the application of thismaterial [11–13].

Depending on working circumstances, it can be observed eithera rapid deterioration of parts if wear is faster than work harden-ing or a progressive decrease of wear when work hardening occursfaster than wear. Many attempts to improve mechanical proper-ties and wear resistance of austenitic Fe–Mn steel have been madeby varying Mn/C ratio and/or introducing new alloying elements[14–19], which leads to some interesting results, but is often moreexpensive.

1.1. Service loading and damaging of railroad crossings

In service, crossings are submitted to rolling stresses, whichcan be considered perpendicular to contact surface, at least onstraight tracks. However, rail crossings are also submitted to shearstresses in many possible directions. These tangential forces are

648 R. Harzallah et al. / Wear 269 (2010) 647–654

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Table 1Chemical composition of Hadfield steel for rail crossing alloy X120Mn12.

grain (300 �m in size) with distinct grain boundaries of regularthickness. No evidence of carbide was observed. The Vickers hard-ness (HV 0.2) is between 220 and 240 HV depending on testedgrains.

ig. 1. (a) Transversal crossing cross section with longitudinal crack in surfacebserved by optical microscopy and (b) evolution of in-depth micro-hardness at 2 Nnder the rolling surface in comparison to hardness resulting form manufacturing.

ll the larger as the crossing is located in a curve. The peculiar-ty of crossings is the impact loading resulting form the changen rolling planes (inclination and section) from the wing rail to theose. These repeated contact stresses harden the top surface layers.ccording to Wiest et al. [20] the contact forces between the wheelnd the crossing nose can reach 2–4 times the value of the staticheel load. In field measurements of the vertical force exerted on

he wheel by different rail tracks confirm this magnitude and showhat transient loads from 1.3 to almost 6 times the static load canccur [21] as a function of the quality of the track. The processeaches the fatigue limit of the material when wear cannot hold inhis rise in hardness. Several kinds of damage can be seen amonghich cracks (Fig. 1a) are the most common, and need frequentaintenance operations which occur at the cost of traffic.In the case of rail crossings in Hadfield steel, the in-depth hard-

ess curve resulting from service loading (see Fig. 1b) is differentrom that obtained by sliding, shot peening and abrasive testseported in [1]. In fact, these tests produce a higher hardening (max-mum value between 600 and 800 HV 0.01) which does not affectlarge depth. A maximum affected depth of about 0.5 mm can bebtained by shot peening.

Rolling tests under lubricated conditions reported in literature1] show that the maximum hardness of the work hardened layer

ncreases, according to a linear relation, when the applied contacttresses increase. However, the in-depth hardness profile shows aaximum value beneath the surface. Fatigue cracks are initiated

t the depth where the maximum shearing stress is located, andegin to propagate in circular arcs towards the inside, then change

C Si Mn P S Cr

1.138 0.46 12.89 0.033 0.008 0.18

direction and propagate parallel to the surface but at a greater depththan the maximum shearing stress. In field cracking on the contrarystarts from the surface (see Fig. 1a) and then propagates parallel tothe surface.

The worn surface of Hadfield steel looks rough with pitting,whether it has been work hardened before service or not. Thesefeatures are commonly observed when rail crossing are examinedin service, especially at the nose which has an orange peel looking.

Rolling contact fatigue has been studied by many authors, inorder to optimize the choice of railway material [22–25]. In thesestudies, the rolling contact fatigue resistance of many railway mate-rials was tested on disc/disc test rigs. Other works [26–28] haveinvestigated the influence of some parameters such as surfaceintegrity and geometry of rail/wheel on contact fatigue resistance.Recent studies [29–32] approach the rolling fatigue contact prob-lem in general cases, introducing other parameters like damage andresidual stresses.

2. Material and experimental procedure

The steel used for rail crossing is Hadfield steel with 1–1.4% C and10–14% Mn contents and additions of other alloying elements suchas chromium and silicon. Results of analyses are shown in Table 1.Chromium is to improve the yield stress and in consequence wearresistance and plastic deformation in service. Silicon has the sameeffect as Chromium on mechanical properties, and enhances deox-idation of the steel. Phosphorus is detrimental to high temperatureductility when its content exceeds 0.06% [1]. For this steel: Mneq

∼27.7 and Mn/C ∼11.3.The as-cast structure of Hadfield steel shows an austenitic

matrix with intergranular carbides. High temperature solutioningprior to water quenching is necessary to avoid carbides in grainboundaries which embrittle the structure.

The microstructure study was performed on bars of 10 mmdiameter, machined from billets elaborated in the same conditionsas industrial parts. Fig. 2 shows the microstructure of Hadfield steelafter water quenching. It is an austenitic structure with a coarse

Fig. 2. Microstructure of X120Mn12 alloy after water quenching (opticalmicroscopy).

R. Harzallah et al. / Wear 269 (2010) 647–654 649

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Fig. 4. Rolling test – (a) specimen holder and (b) specimen geometry.

Table 2Mechanical properties of Hadfield and 100Cr6 steel.

Steel grade Yield strength Ultimate tensile Hardness

bearings that support them inside the sample holder.

Fig. 3. Rolling test. CEMEF tribotester.

The rolling micro-sliding test was carried out on the Cemef tri-otester (Fig. 3). It consists of the application of load 3 F normal toaxisymmetric specimens rolling on their own axis. These speci-ens are inserted between two plane discs, the upper disc being

xed in the test rig, while the lower disc rotates. This test aimst investigating the influence of loading frequency and number ofycles on the plastic deformation and hardening of test material.

The axial load has been set at 700 N which produces an approxi-ate initial Hertzian stress of 2200 MPa (obtained by measurement

hrough pressure paper). Two rotation speeds have been used:1 = 275 r/min (∼9 Hz) and V2 = 1375 r/min (∼46 Hz). Some testsave been performed at 350 N axial load.

The Cemef tribotester (Fig. 3) is made of two discs. The lowerne can be rotated by an electric motor and the upper one is ableo translate along the normal axis thanks to a pneumatic cylin-er, which puts both discs in contact with an axial load 3 F thatetermines the contact pressure.

The axial load, the running torque and the displacement of upperisc are measured by sensors. The test rig in Fig. 4 shows both discsnd the specimen holder.

The upper disc holds a track made of steel 100Cr6 (Table 2) prop-erly heat treated and machined.The lower disc holds another track made of the same 100Cr6.

Fig. 5. Schematic view of specime

(MPa) strength (MPa)

Hadfield 400 1000 220 HV100Cr6 1700 2300 61 HRC

• The sample holder in which 3 axisymmetric specimens areinserted.

Three specimens are tested at a time, so as to equilibrate the testrig and to assess reproducibility of the test.

The geometrical shape of specimen shown in Fig. 4b was chosenso to have a punctual contact with a plastic flow of material.

Under the rolling of lower disc and the load applied by the upperdisc, the specimens are free to roll on their own axis thanks to ball

When the lower disc runs at 10 r/min, the specimen is at275 r/min and the linear velocity is 115 mm/s. The cycle numbercan be calculated from the R/r ratio (R: the disc radius and r: thespecimen radius), the rolling velocity and the duration of the test.

n contact with rolling discs.

650 R. Harzallah et al. / Wear 269 (2010) 647–654

and (b) micro-hardness in longitudinal section.

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hardness keeps rising with cycle number and reaches 1000 HVafter 150 thousand cycles. It is worthy to note that the values mea-sured in the cross section at a depth of 0.1 mm from the surfaceare lower.

Fig. 6. Measurements: (a) contact width

Fig. 5 shows a schematic view of specimen contact with rollingiscs. The parallelism of discs was verified using pressure papermanufactured by Fuji), which enables to show the contact regionf the 3 specimens.

Fig. 6a shows the surface of the contact region of specimenfter test. It can be seen that the grooves resulting from cutting orachining have been erased over a small area which therefore cor-

esponds to the actual contact area of specimen with rolling disks.he width of this region can be measured. Here it is equal to 2 mm,nd cannot exceed the gage length of specimen which is equal to.2 mm.

Tests have been performed up to 150 thousand cycles, whichave been decomposed into 9 steps of about same duration. Obser-ations and micro-hardness measurements have been performedoth at the surface and in a longitudinal cross section of the speci-en.

At the surface, the contact width (Fig. 6a) and the Vickers hard-ness (under a load of 2 N) in the most loaded region have beenmeasured on the same specimen by the end of every step. Thensurface hardening and contact width can be obtained as a functionof cycle number.In the longitudinal section, the evolution of Vickers micro-hardness under a load of 2 N and a load of 0.25 N, has been checkedin subsurface depth at 50, 100 and 150 thousand cycles (3 dif-ferent specimens), which enables to study the influence of cyclenumber on hardening and microstructure.

. Results and discussions

.1. Influence of cycle number

The main parameter in the investigation of rolling contactatigue is the number of cycles. In fact, for the same applied load of00 N and the same rolling speed of 275 r/min, X120Mn12 showshe highest surface hardness at 150 thousand cycles. Hardeningccurs along with an evolution of contact width which increasesith cycle number.

Fig. 7 shows that the rise in superficial hardness and contactidth is very fast in the first 15 thousand cycles, and then the

ncrease is slower until 150 thousand cycles. The surface hardnessfter 150 thousand cycles is equal to 1000 HV, which is 4 timesigher than the initial hardness. The contact width is limited to thepecimen gage length.

Figs. 8 and 9 show the in-depth evolution of micro-hardness

rom the surface for the specimen in initial state (hardness resultingrom cutting and machining), and after 50, 100 and 150 thousandycles.

In the initial condition, the subsurface of sample is affected byutting with a superficial hardness of 400 HV and depth of 200 �m.

Fig. 7. Evolution of micro-hardness at surface and contact width as a function ofcycle number (V = 275 r/min; F = 700 N).

In comparison to the values observed in samples from rail crossing(Fig. 1b) after manufacturing, the superficial hardness is almost thesame, but the affected depth is much lower.

• After 50 thousand cycles, the surface hardness is 800 HV (twicethe initial hardness). The hardness resulting from initial elabora-tion of X120Mn12 can be found at 1 mm from surface. The surface

Fig. 8. Evolution of in-depth micro-hardness at 2 N in longitudinal section of rollingsample under F = 700 N and V = 275 r/min (point 0 is obtained by indentation normalto the surface).

R. Harzallah et al. / Wear 269 (2010) 647–654 651

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ig. 9. Evolution of in-depth micro-hardness at 0.25 N in longitudinal section ofolling specimen under F = 700 N and V = 275 r/min (point 0 is obtained by indenta-ion in the section near surface).

From the surface down to 0.5 mm in-depth, the values of micro-hardness measured with 0.25 N are higher than those observedwith 2 N. This size effect, which can be classically observed forthis kind of alloy, is all the more highlighted in this area as thereis a strong hardening of the superficial region.The vertical displacement sensor does not detect any signifi-cant plastic deformation of the samples, which suggest that thevery high hardening is provided by piling up superficial shear-ing, without metal loss by abrasive wear, sliding being very low(micro-sliding).The thickness of affected subsurface remains similar. Detailedexaminations show that the hardness of the affected subsur-face layer decreases at middle thickness which suggests a slightcollapse of the hardened layer. The deformation seems to con-centrate at the subsurface and could be followed by spalling.

.2. Influence of rolling speed

The rolling speed has some influence on the rolling behaviourf the material. In fact, for the same cycle number (150,000) andpplied load (700 N), the steel shows a micro-hardness (Fig. 10)00 HV higher at the surface and 100 HV at 300 �m in subsurfaceor the speed V2 than for V1 (V2 is 5 times V1). After 300 �m in-depthhe micro-hardness for the speed V2 becomes lower than that mea-ured for the speed V1. It follows that for V2 the hardness is higher

ut more concentrated at the surface. The increase in rolling speedhifts the micro-hardness in-depth measurement with a close toonstant value for the first 300 �m in subsurface.

ig. 10. In-depth micro-hardness in longitudinal section of rolling specimen after50 thousand cycles under V1 = 275 r/min and V2 = 1375 r/min (F = 700 N) – zoom atubsurface with 0.25 N (point 0 is obtained by indentation near surface).

Fig. 11. In-depth micro-hardness in longitudinal section of rolling specimen after150 thousand cycles under F1 = 350 N and F2 = 700 N for V = 1375 r/min.

The influence of rolling speed is in agreement with the mechan-ical behaviour observed in high strain rate compression testsperformed for comparison, as well as in high rate tensile testsreported in [9]. The stress increases with strain, but decreases whenstrain rate increases. In the rolling test, since the stress is set bythe axial loading, the increase in rolling speed which increases thestrain rate, should lead to an increase in strain. It can be observedthat hardening and therefore deformation increase in the superfi-cial area while they decrease in subsurface. It is difficult to assessthis deformation for many reasons. The strain in compression testsis limited to 0.6 (true strain), which results in a lower hardness(550 HV 0.2) than that observed at the surface of the specimen. Incompression the stress has not a linear evolution with strain; theloading is also different from monotonic in compression to cyclicin rolling test.

In comparison to the test specimens, it has been measured thatfor rail crossings the surface hardness resulting from manufactur-ing is almost the same with a higher affected depth, while it is lowerafter service (about 600 HV with an affected depth of 8 mm). Thislower value may result from in-service spalling or metal loss bywear in surface.

3.3. Influence of applied load

Specimens have been tested up to 150 thousand cycles, using arolling speed of 1375 tr/min and two different applied loads (350and 700 N), in order to study the influence of applied load. The dis-tributions of micro-hardness by the end of the test are shown inFig. 11. The affected depth is the same for both loads, but the hard-ness is 200 HV higher for the highest applied load. The values ofin-depth micro-hardness are increased by 200 HV in the affectedarea, when the applied load changes from 350 N to 700 N.

In this load range it seems that the variation of axial load shouldonly affect hardness, by a simple shift in the values. The limitednumber of tests and applied load range make it nonetheless difficultto draw conclusions.

3.4. Surface analysis

Observations of contact surface were performed before and afterrolling tests by optical microscopy (Fig. 12). Before the test, thespecimen shows a rough surface, which disappears as the cyclenumber increases because of the contact with the tracks supported

by the rolling discs. It results an increase in contact surface withcycle number.

Scanning electron microscopy observation of contact surfaceafter 150 thousand cycles (Fig. 13), shows a “sponge-like” aspect,with micro-spalling. These could result from micro-scaling which

652 R. Harzallah et al. / Wear 269 (2010) 647–654

Fig. 12. Contact surface observation (a) initial state and (b

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microstructure, which can be seen just below this area.

ig. 13. Contact surface observation after 150 thousand cycles (F = 700 N;= 275 r/min).

ould occur as a consequence of rolling contact fatigue. In fact,he size of micro -voids observed at specimen surface corresponds

o that of tiny particles observed at rolling discs surface after 150housand rolling cycles. The small amount of micro-spalling con-rms the outstanding ability of Hadfield steel to accommodate largetrains.

Fig. 14. Microstructure evolution with rolling

) after 150 thousand cycles (F = 700 N; V = 275 r/min).

3.5. Microstructure

Microscopic examination of the Nital etched microstructure(Fig. 14) in longitudinal section of specimen shows large changesunder the contact surface as a function of cycle number. In fact, inthe initial state, some deformation bands can be seen, which resultfrom cutting. Their number increases with the cycle number untilproducing a thick disturbed area where features become hard todistinguish. Meanwhile there is a continuous increase in hardnessat the surface (Fig. 7).

Two areas can be distinguished under the contact surface in thelongitudinal section of rolling specimen after 150 thousand cycles(Fig. 15 a and c):

• The first one, close to the surface, has a thickness of about 200 �m.It is highly disturbed meaning the material has been heavilywrought. Micro-cracks can be seen in the contact zone.

• The second area has a thickness of about 400 �m. Very deformedgrains with high twin density can be seen just below the disturbedfirst layer. As the distance from surface increases grain shape andtwin density gradually retrieve the characteristics of the initial

The second area has the same microstructure and level of hard-ness as observed near the surface of worn rail crossings.

cycles number (F = 700 N; V = 275 r/min).

R. Harzallah et al. / Wear 269 (2010) 647–654 653

Fig. 15. Microstructure of rolling specimen after 150 thousand cycles (F = 700 N; V = 275 r/min): (a and c) longitudinal section and (b) cross section.

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Fig. 16. Effect of rolling speed on final micr

The transverse section (Fig. 15b), shows micro-cracks starting aturface and propagating inside the specimen. These micro-cracksre characteristic of rolling contact fatigue.

The influence of rolling speed on microstructure is shown in

ig. 16. It can be seen that the subsurface material is more heav-ly wrought with the highest rolling speed. The affected width isarger. However, the affected depth is similar. This observations confirmed by hardness measurements in longitudinal sectionFig. 10).

Fig. 17. Effect of applied load on final microstructu

cture after 150 thousand cycles (P = 700 N).

Fig. 17 shows a comparison of microstructure after rolling testsat 150 thousand cycles and 1375 r/min for 350 N and 700 N appliedload. For the applied load of 350 N, the microstructure showsequiaxed austenitic grains with some deformation bands, while in

the specimen tested at 700 N the subsurface is so disturbed thatno feature can be distinguished. This accounts for the difference inhardness in this area which is about 200 HV (Fig. 11).

Electron backscatter diffraction (EBSD) has been used to inves-tigate the deformation bands (Fig. 18). At 0.3 strain level in tensile

re after 150 thousand cycles (V = 1375 r/min).

654 R. Harzallah et al. / Wear 2

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Fig. 18. Microstructure at 0.3 strain level in tensile specimen.

pecimen, EBSD patterns show high mechanical twinning (largeoloured deformation bands) and also slip bands (deformationands in grey have a very small disorientation with their sur-oundings). The patterns for rolling specimen at 10,000 cycles showlip bands and very few twinning below the contact surface. After0,000 cycles, the surface just below contact is too disturbed forBSD patterns to be distinguished. However underneath slip bandsnd twins can be seen. With increasing number of cycles, the deptht which EBSD patterns could be resolved increased and no infor-ation could be obtained at the contact surface of the specimens.

he high level of strain in the microstructure of the specimensay account for difficulties in determining the nature of flow

ines by EBSD. The same problem occurred with EBSD patterns ofompressive specimens with 0.6 strain level. Besides, no evidencef martensitic transformation was observed in the specimens.train should then be essentially accommodated by slipping andwinning.

These observations show that rolling under an applied loadas a large influence on microstructure and superficial hard-ess of parts in steel X120Mn12. Its value increases withpplied load and speed and in particular with cycle number.he thickness of the very disturbed subsurface area has theame evolution. The rolling–micro-sliding tests can reproduce thehape of in-depth profile observed in service, which were notbtained in pure rolling lubricated tests reported in [1]. How-ver, the hardness level and microstructure of the contact areare different from those resulting from service loading, whichxhibit lower strain. It might be explained by removal of theost strained material by wear. Investigations on service load-

ng taking strain rate into account are needed to clear thisssue.

. Conclusions

The effect of rolling contact on mechanical behaviour of Had-eld steel has been studied by tests on rotary tribotester equippedith a specific test rig. The effect of such parameters as applied

oad, rolling speed and cycle number has been studied. This studyonfirms the very high work hardening capacity of this alloy. Theickers hardness at the surface reaches 1000 after 150 thousand

olling cycles. This hardness decreases with decreasing appliedoad, and increases with increasing rolling speed. The contacturface enlarges with increasing cycle number and shows micro-racks and micro-voids by the end of the test, which meansicro-spalling initiation

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69 (2010) 647–654

References

[1] F. Maratray, High Carbon Manganese Austenitic Steels, The International Man-ganese Institute, 1995.

[2] G. Collette, C. Crussard, A. Kohn, J. Plateau, G. Pomey, M. Weisz, Contribution àlétude des transformations des austénites à 12% Mn, Revue de Métallurgie LIV6 (1957) 433–481.

[3] L. Remy, Temperature variation of the intrinsic stacking faults energy of a highmanganese austenitic steel, Acta Metallurgica 25 (1977) 173–179.

[4] Y. Tsakiris, D.V. Edmonds, Martensite and deformation twinning in austeniticsteels, Materials Science and Engineering A 273–275 (1999) 430–436.

[5] F.D. Fischer, T. Schaden, F. Appel, H. Clemensc, Mechanical twins, their develop-ment and growth, European Journal of Mechanics A/Solids 22 (2003) 709–726.

[6] S. Allain, J.-P. Chateau, O. Bouaziz, A physical model of the twinning-inducedplasticity effect in a high manganese austenitic steel, Materials Science andEngineering A 387–389 (2004) 143–147.

[7] S. Allain, J.-P. Chateau, O. Bouaziz, S. Migot, N. Guelton, Correlation betweenthe calculated stacking fault energy and the plasticity mechanisms in Fe–Mn–Calloys, Materials Science and Engineering A 387–389 (2004) 158–162.

[8] S. Allain, J.-P. Chateau, D. Dahmoun, O. Bouaziz, Modeling of mechanical twin-ning in a high manganese content austenitic steel, Materials Science andEngineering A 387–389 (2004) 272–276.

[9] E. Bayraktar, F.A. Khalid, C. Levaillant, Deformation and fracture behaviour ofhigh manganese austenitic steel, Journal of Materials Processing Technology147 (2004) 145–154.

10] A. Dumay, J.-P. Chateau, S. Allain, S. Migot, O. Bouaziz, Influence of additionelement on the stacking fault energy and mechanical properties of an austeniticFe–Mn–C steel, Materials Science and Engineering A 483–484 (2008) 184–187.

11] S. Bahattacharyya, A friction and wear study of Hadfield manganese steel, Wear9 (1966) 451–461.

12] N. Jost, I. Schmidt, Friction induced martensitic transformation in austenitemanganese steels, Wear 111 (1986) 377–389.

13] W. Yang, L. fang, K. Suna, Y. Xub, Effect of work hardening on wear behavior ofHadfield steel, Materials Science and Engineering A 460–461 (2007) 542–546.

14] T.H. Middeham, Some alloy addition to manganese steel, Alloy Metals Review(1964).

15] L. Moulin, M. Lacoude, R. Tricot, A. Gueussier, Contribution à létude desausténites au manganèse à écrouissabilité améliorée, Revue de métallurgie(1970) 465–472.

16] D.C. Richardson, W.B.F. Mackay, R.W. Smith, An improved Hadfield steel foruse in railway castings, Solidification Technology, 409–413, The Metals Society,Warwick, England, 1981.

17] R.W. Smith, A. De Monte, W.B.F. Mackay, Development of high-manganesesteels for heavy duty cast-to-shape applications, Journal of Materials ProcessingTechnology 153–154 (2004) 589–595.

18] D. Canadinc, H. Sehitoglu, H.J. Maier, Y.I. Chumlyakov, Strain hardening behav-ior of aluminum alloyed Hadfield steel single crystals, Acta Materialia 53 (2005)1831–1842.

19] L. Chebgsin, W. Guixin, W. Yabdong, L. Qingsuo, Z. Jiunjun, Effect of V andC on strain recovery characteristics in Fe–Mn–Si alloy, Material Science andEngineering A 438–440 (2006) 808–811.

20] M. Wiest, W. Daves, E.D. Fischer, H. Ossberger, Deformation and damage of acrossing nose due to wheel passages, Wear 265 (2008) 1431–1438.

21] P. Gullers, L. Andersson, R. Lundén, High-frequency vertical wheel-rail con-tact forces—field measurements and influence of track irregularities, Wear 265(2008) 1472–1478.

22] W.R. Tyfour, J.H. Beynon, A. Kapoor, The steady state wear behaviour of pearliticrail steel under dry rolling–sliding contact conditions, Wear 180 (1995) 79–89.

23] M. Hiensch, P.-O. Larsson, O. Nilsson, D. Levy, A. Kapoor, F. Franklin, J. Nielsen,J.W. Ringsber, B. Lennart Josefson, Two-material rail development: field testresults regarding rolling contact fatigue and squeal noise behaviour, Wear 258(2005) 964–972.

24] F.J. Franklin, G.-J. Weed, A. Kapoor, E.J.M. Hiensch, Rolling contact fatigue andwear behaviour of the infrastar two-material rail, Wear 258 (2005) 1048–1054.

25] R.I. Carroll, J.H. Beynon, Decarburisation and rolling contact fatigue of a railsteel, Wear 260 (2006) 523–537.

26] D.T. Eadie, D. Elvidge, K. Oldknow, R. Stock, P. Pointner, J. Kalousek, P. Klauser,The effects of top of rail friction modifier on wear and rolling contact fatigue:Full-scale rail–wheel testirig evaluation, analysis and modelling, Wear 265(2008) 1222–1230.

27] Y. Satoh, K. Iwafuchi, Effect of rail grinding on rolling contact fatigue in railwayrail used in conventional line in Japan, Wear 265 (2008) 1342–1348.

28] J.E. Garnham, C.L. Davis, The role of deformed rail microstructure on rollingcontact fatigue initiation, Wear 265 (2008) 1363–1372.

29] N. Govindarajan, R. Gnanamoorthy, Study of damage mechanisms and failureanalysis of sintered and hardened steels under rolling–sliding contact condi-tions, Materials Science and Engineering A 445–446 (2007) 259–268.

30] D. Canadinc, H. Sehitoglu, K. Verzal, Analysis of surface crack growth underrolling contact fatigue, International Journal of Fatigue 30 (2008) 1678–1689.

31] C. Richard, L.Y. Choi, Rolling contact fatigue life model incorporating resid-ual stress scatter, International Journal of Mechanical Sciences 50 (2008)1572–1577.

32] Y.B. Guo, A.W. Warren, The impact of surface integrity by hard turning vs.grinding on fatigue damage mechanisms in rolling contact, Surface & CoatingsTechnology 203 (2008) 291–299.