Wear 269 (2010) 664671

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Yucel BirMaterials Instit

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Article history:Received 11 MReceived in reAccepted 7 JulAvailable onlin

Keywords:Sliding wearSteelHigh temperatWear testing

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1. Introdu

High temmetallic sutemperaturof mechaniicant role of the latter in high temperature sliding wear wasrst identied by Fink [5]. It is well known that oxidation leadsto material degradation and consequently, reduces the materialresistance to wear. However, a surface oxide may reduce theoxidation rate and help to decrease the wear loss if it is denseand strongwas discusture wear [reviewed bpretation o[19].

High temmechanismvery attractfor drive untool materia[22]. The codeterioratesion of hardcobalt-baseing resistan

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[3337]. It is thus of great technological interest to explore theirwear resistance at high temperatures. While the ambient temper-ature wear performance has been investigated in detail, publishedinformation on the wear performance of these alloys at high tem-peratures is scarce. Thepresentworkwasundertaken to investigate

0043-1648/$ doi:10.1016/j.[6,7]. The role of oxide scale in the wear of metalssed extensively both for ambient and high tempera-816] while the mechanisms of oxidation wear werey Quinn [17,18]. Some new approaches on the inter-f oxidation wear mechanisms have also been proposed

perature wear is identied to be a potential failurefor thixoforging tools [20,21]. While thixoforging is aive processing route for the manufacture of steel partsits and chassis components, it is very demanding onls with high process temperatures involved (>1300 C)nventional hot work tool steels were shown to rapidlyunder such severe conditions [2327]. With a disper-carbide particles in a cobalt-rich solid solution matrix,alloys are exceptionally good for applications requir-ce to oxidation and wear [2831]. Ni-base alloys are

62 6773084; fax: +90 262 6412309.ress: yucel.birol@mam.gov.tr.

the high temperature sliding wear resistance of Stellite 6 andInconel 617 alloys and rate their performance against that of theconventional hot work tool steel employed in hot forging of steelcomponents.

2. Experimental

A CETR Universal Material Tester-2 model ball-on-disc type tri-bometer (Fig. 1) was used to investigate the high temperature wearproperties of Inconel 617 and Stellite 6 alloys and X32CrMoV33 hotwork tool steel (Table 1).Wear testswere carried out at 750 Cwitha sliding speed of 0.025m/s, under 5N load for 60min. The testtemperature was selected with a consideration of the maximumtemperature achieved at the surface of the die cavity during steelthixoforming experiments [33]. Since the tool is abraded by verysmall-Feparticles thatmakeup the solid fractionof the semi-solidfeedstock, the ball diameter and the applied load were selected soas toproducea scratching case. A0.001mdiameter aluminaball ranover disk samples over a circular path having a diameter of 0.03m.The disc surfaces were ground with a 1000 mesh grit sandpaper

see front matter 2010 Elsevier B.V. All rights reserved.wear.2010.07.005mperature sliding wear behaviour of In

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The high temperature wear performapared with that of the X32CrMoV33 hjudged to be very poor due basically towith wear at 750 C leads to substantisufciently ductile to sustain the weInconel 617 and Stellite 6 alloys at 75Inconel 617 andStellite 6 alloys sustaifor the superior wear resistance of th

ction

perature wear is one of the life-limiting factors whenrfaces are in repeated contact [13]. High forminges impact the wear behaviour of tools through losscal strength and enhanced oxidation [4]. The signif-

also atoxidattempe

Co-for thement [m/locate /wear

nel 617 and Stellite 6 alloys

f Inconel 617 and Stellite 6 alloys was investigated and com-ork tool steel. The wear performance of the latter at 750 C isferior oxidation resistance. Extensive oxidation co-occurringterial loss basically due to the lack of an adhesive oxide scale,tion without extensive spalling. The wear resistance of thes relatively superior. The adhesive oxides growing slowly onwear actionwithout spalling andare claimed tobe responsibleloys at 750 C.

2010 Elsevier B.V. All rights reserved.

ive high temperature materials owing to an excellentesistance, creep strength and phase stability at highes [32].Ni-based high temperature alloys were tested recentlytential to withstand the steel thixoforming environ-6]. Their thermal fatigue performance is encouraging

Y. Birol / Wear 269 (2010) 664671 665

Table 1Chemical composition of the X32CrMoV33 hot work tool steel and Ni- and Co-based high temperature alloys used in the present work.

Alloy C Si Mn Cr Mo Ni Al Co Cu Nb Ti V W Fe

X32CrMoV33 0.281 0.190 0.200 3.005 2.788 0.221 0.025

666 Y. Birol / Wear 269 (2010) 664671

Fig. 4. Friction coefcient curves of the X32CrMoV33, Inconel 617 and Stellite 6 disc samples submitted to ball-on-disc sliding wear test at 750 C.

3. Results and discussion

Two- and three-dimensional prolometer images and two-dimensional surface proles of the tested surfaces are illustratedin Fig. 2. The widest and the deepest wear track, and thus the high-

Fig. 5. Opticaldisc samples s

est volume loss occurred in the hot work tool steel. It is clear fromFig. 2 that the surface of the hot work tool steel disc sample hasdeteriorated not only inside but also outside the wear track, due tothe extensive oxidation suffered by this material at the test tem-perature. The width and the depth of the wear tracks are relativelysmaller in the Inconel 617 alloy and the smallest in the Stellite 6alloy. These are consistent with the wear volume loss measure-ments which clearly identify the hot work tool steel to be the leastand the Stellite 6 alloy the most resistant to sliding wear at 750 C(Fig. 3).

The friction coefcients measured during the sliding wear testsare shown in Fig. 4. The friction coefcient of the X32CrMoV33 hotmicrographs of (a) X32CrMoV33, (b) Inconel 617 and (c) Stellite 6ubmitted to ball-on-disc sliding wear test at 750 C.

Fig. 6. OpticaX32CrMoV33,l micrographs showing transverse section of the wear track of (a)(b) Inconel 617 and (c) Stellite 6 disc samples.

Y. Birol / Wear 269 (2010) 664671 667

work tool steel is as low as 0.2 at the start of the test and increaseswith time to approximately 0.4. The thick oxide layer formed onthe surface of the tool steel at 750 C is believed to have served asa lubricant leading to a low friction coefcient initially. Low fric-tion coefcients are linked with poor adherence and thick oxidelayers [38,39] which help to enlarge the contact surface therebydecreasing the strain and thus the friction coefcient [40]. Smallinitial friction coefcient values may also be accounted for by thesudden loss of strength upon thermal exposure. The decohesion of

Fig. 7. ScanniStellite 6 disc

oxide scales, generation and accumulation of debris in the contactzone are responsible for the relatively larger uctuations and foran ever-increasing friction coefcient. It is inferred from these fea-tures of the friction coefcient curve that the oxide layer on the toolsteel disc sample is not stable.

The friction coefcient curves of the Inconel 617 and Stellite 6alloys are markedly different. That of the former is stabilized at

cannidiscng electron micrographs of (a) X32CrMoV33, (b) Inconel 617 and (c)samples submitted to ball-on-disc sliding wear test at 750 C.

Fig. 8. SStellite 6ng electron micrographs of (a) X32CrMoV33, (b) Inconel 617 and (c)samples submitted to ball-on-disc sliding wear test at 750 C.

668 Y. Birol / Wear 269 (2010) 664671

Fig. 9. Scanning electron micrograph of the glazed layer in Inconel 617 disc samplesubmitted to ball-on-disc sliding wear test at 750 C.

approximately 0.24 and remains more or less constant with slidingtime after an initial running-in period of about 500 s. The frictioncoefcient of Stellite 6 alloy shows a similar trend but runs at ahigher value, at approximately 0.48. It is fair to conclude that thefriction and wear conditions are quite stable in the Inconel 617 andStellite 6 alloys owing to a stable oxide layer.

The optical micrographs of the wear tracks are shown in Fig. 5.Interestingly, the microstructural features are readily identiedon Inconel 617 and Stellite 6 disc samples without the benet ofchemical etching. This is typical of a well known practice in met-allography [41] and evidences a thin oxide lm which helps todelineate the microstructure under cross polarizer. This effect isnot offered by the hot work tool steel disc sample simply due toa much thicker oxide all over. Further evidence for the extent ofoxidation in the three alloys is available in the transverse sectionsof the wear tracks in the respective disc samples (Fig. 6). A verythick oxide scale is evident in the hot work tool steel sample whileoxide lms on the Inconel 617 and Stellite 6 alloys are apparently

Fig. 10. Elemesamples submnt distribution proles (a, b, c) and oxygen distribution proles (d, e, f) across the wear titted to ball-on-disc sliding wear test at 750 C.racks of (a, d) X32CrMoV33, (b, e) Inconel 617 and (c, f) Stellite 6 disc

Y. Birol / Wear 269 (2010) 664671 669

too thin to be resolved with an optical microscope. The former hasapparently failed to sustain the wear loading and has fractured toproduce oxide debris in the wear track.

Abrasivewearwith grooving in the slidingdirection, a very thickoxide layer and an appreciable quantity of debris accumulated atthe edges of the track were the basic wear features for the hot worktool steel (Figs. 7 and 8). The oxides along the edges of the weartrack were inferred from their colour to be hematite, in contrast tothe dark-coloured magnetite covering the disc surface. The oxidedebris was apparently carried to the edge of the track by the alu-minaballwhere it has oxidised again.Magnetite reactswithoxygento produce hematite. Oxidation, fresh surface generation via frac-

ture and removal of the surface oxides inside the wear track andreoxidation of the fresh surface are claimed to be responsible forthe substantial wear loss suffered by the hot work tool steel. Theremoved oxide itself might have acted as an abrasive agent whilststill within thewear interface producing an abrasive element in thewear of X32CrMoV33. Fig. 7a suggests that this is a likely mecha-nism when the oxide debris does not readily sinter to form a glazeand act as a third body abrasive [11].

The features of the worn surfaces of the Inconel 617 and Stellite6 alloys are markedly different (Figs. 7 and 8). The oxides on theInconel 617 and Stellite 6 samples are very thin. The oxide debris,although much less in quantity, was somehow retained inside the

Fig. 11. 6 discXRD spectra obtained from the tested surfaces of (a) X32CrMoV33 and (b) Stellite samples submitted to ball-on-disc sliding wear test at 750 C.

670 Y. Birol / Wear 269 (2010) 664671

wear track and was compacted into a glazed surface [2,42,43]. Thehigh hardness of the alumina ball and its capacity to form largegroves so as to retain the oxide debris inside the wear track mighthave been critical in glazed layer formation. While the glazed layeris continuothe wear trcontinuousThe glazedresponsibleperatures aa plausible617 alloy w(Fig. 9).

It is infewear tracksoxygen conoutside whtion of fresand subseqhigher oxygeven strongis not evideto be heavil

It is faitemperaturpresent wo750 C. Thethe thicknescales [45,4is shown byThe poor adthe failure ovated tempappears toalloys, as inpoorwear rhighly plason the surfaon the othebe responsi750 C as sutwo alloysthus improvalloys rely oof 20wt% Cr[49]. With aSi and Al, thous protectThe strain-ito hexagonplane to thereduced we

Wear reat high teX32CrMoV3with a sharmost hot w600 C [52]work tool sume loss itother handmore wearwear volumgesting thapresent woature.

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rk tooFink, Wear oxidationa new component of wear, Trans. Am. Soc. Steel 1830) 10261034.. Aoh, J.-C. Chen, On the wear characteristics of cobalt-based hardfacinger after thermal fatigue and oxidation, Wear 250 (2001) 611620.. Stott, The role of oxidation in the wear of metals, Tribol. Int. 31 (1998)71.J. Quinn, J.L. Sullivan, D.M. Rowson, Origins and development of oxidationalar at low ambient temperatures, Wear 94 (1984) 175191.Tu, X.H. Jie, Z.Y. Mao, M. Matsumara, The effect of temperature on theubricated sliding wear of 5 CrNiMo steel against 40 MnB steel in the range600 C, Tribol. Int. 31 (1998) 347353.adu, D.Y. Li, Investigation of the role of oxide scale on Stellite 21 modi-with yttrium in resisting wear at elevated temperatures, Wear 259 (2005)458.Inman, S.R. Rose, P.K. Datta, Studies of high temperature sliding wear oftallic dissimilar interfaces II: Incoloy MA956 versus Stellite 6, Tribol. Int. 3906) 13611375.Roy, A. Pauschitz, J. Wernisch, F. Franek, Effect of mating surface on the highperature wear of 253 MA alloy, Mater. Corros. 55 (2004) 259273.us in the Inconel 617 alloy and marks the boundary ofack all around the disc sample, it is revealed as dis-patches inside the wear track in the Stellite 6 alloy.surfaces in the contact zone have been reported to befor the relatively lower friction coefcients at high tem-s they increase the carrying surface [44]. This could beaccount of the low friction coefcient in the Inconelhere the glazed layer in the wear track is uninterrupted

rred from the increased signal intensities across theof the Inconel 617 and Stellite 6 disc samples that thecentration is greater inside the wear tracks than it isere oxidation has occurred statically (Fig. 10). Genera-h surface and defects due to abrasion via sliding wearuent reoxidation may be responsible for the relativelyen levels inside thewear tracks. Oxygen signals becomeer when crossing the glazed layers. Such a signal prolent in the case of the hotwork tool steelwhich is believedy oxidised both inside and outside the wear track.r to conclude from the foregoing that the high-e wear performance of the three alloys tested in therk is closely linked with their oxidation behaviour attribological behaviour is strongly affected by thenature,ss, the adherence, and the morphology of the oxide6]. The thick surface oxide layer on the tool steel sampleXRD analysis to consist of Fe3O4 and Fe2O3 (Fig. 11a).herence and limited ductility of these oxides promotef the oxide scale impairing the resistance towear at ele-eratures [47]. Lack of oxide debris sinterability, whichbe adequate in the case of Inconel 617 and Stellite 6ferred from Fig. 8c, might have also contributed to theesistance of the tool steel sample [11]. The adhesive andtic Cr2O3 lm, identied to be the predominant oxidece of both Inconel 617 and Stellite 6 samples (Fig. 11b),r hand, has sustained the abrasion and is claimed toble for the improved wear resistance of these alloys atggested in [47,48]. The reduced oxidation rate in thesesuppresses the synergy between oxidation and wear,ing the resistance to wear at 750 C. High-temperaturen Cr to form protective scales and require a minimumto develop a continuous Cr2O3 lm to enjoy protectionCr content only as much as 3wt% and with hardly anye present hot work tool steel evidently lacks a continu-ive oxide and cannot take advantage of such protection.nduced phase transformation from face-centred-cubical-close-packed structure and alignment of the basaldirection of sliding, could also be responsible for the

ar of the Stellite 6 alloy [50,51].sistance of the X32CrMoV33 tool steel is impairedmperatures also via loss of mechanical strength.3 tool steel responded to thermal exposure at 750 Cp hardness drop (Fig. 12). This is not surprising sinceork tool steels are known to soften starting around. The substantial softening in the X32CrMoV33 hotteel is believed to have been critical in the wear vol-has suffered. Inconel 617 and Stellite 6 alloys, on the, retain their hardness at 750 C and are thus muchresistant owing to a higher resistance to abrasion. Thee loss and hot hardness are inversely proportional sug-t the wear resistance of the three alloys tested in therk is closely linked with their hardness at this temper-

Fig. 12.samples

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[1] I.A.lay461

[2] A. Pat e

[3] X. J[4] Y. B

wo[5] M.

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61[8] T.F.

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[10] I. Red453

[11] I.A.me(20

[12] M.temess measurements of X32CrMoV33, Inconel 617 and Stellite 6 disce and after ball-on-disc sliding wear test at 750 C.

ions

ing wear performance of the X32CrMoV33 hot workdegraded at 750 C due basically to its inferior oxida-

nce. Extensive oxidation co-occurring with abrasion ats to substantial material loss basically due to the lackive oxide scale, sufciently ductile to sustain the abra-without extensive cracking or spalling. Fe3O4 fails toabrasion conditions and is readily detached from thewear resistance of the Inconel 617 and Stellite 6 alloys,r hand, is much better at 750 C. The adhesive and theore plastic Cr2O3 on Inconel 617 and Stellite 6 alloyssliding wear action without spalling and is claimed to

ble for the improved wear resistance of these alloys at

gements

erformed the ball-on-disc wear tests. Prof. M. Urgen isthe provision of the wear test facilities. F. Alageyik andthanked for their help in the experiments and C. Berkin SEM-EDS investigations. This work was funded by

n, S. Datta, H.L. Du, J.S. Burnell-Gray, Q. Luo, Microscopy of glazedmedduring high temperature slidingwear at 750 C,Wear 254 (2003).itz,M. Roy, F. Franek,Mechanisms of slidingwear ofmetals and alloysd temperatures, Tribol. Int. 41 (2008) 584602.. Liu, S.Y. Dong, B.S. Xu, Surf. Coat. Technol. 194 (2005) 10.

D. Isler, Response to thermal cycling of CAPVD (Al,Cr)N-coated hotl steel, Surf. Coat. Technol. doi:10.1016/j.surfcoat.2010.06.038.

Y. Birol / Wear 269 (2010) 664671 671

[13] L. Wang, D.Y. Li, Effects of yttrium on microstructure, mechanical propertiesand high-temperature wear behavior of cast Stellite 6 alloy, Wear 255 (2003)535544.

[14] A.W Batchelor, G.W. Stachowiak, A. Cameron, The relationship between oxidelms and the wear of steels, Wear 113 (1986) 203223.

[15] D.Y. Wang, D.L. Shu, X.C. Guo, Effect of microstructure and properties on thehigh temperature wear characteristics of 3Cr2W8V (H21) steel, Wear 119 (1)(1987) 101117.

[16] M. Vardavoulias, The role of hard second phases in the mild oxidational wearmechanism of high-speed steel-based materials, Wear 173 (1994) 105114.

[17] T.F.J. Quinn, Review of oxidational wear. Part I. The origins of oxidational wear,Tribol. Int. 16 (1983) 257271.

[18] T.F.J. Quinn, Review of oxidational wear. Part II. Recent developments andfuture trends in oxidational wear research, Tribol. Int. 16 (1983) 305315.

[19] S. Mischler, A. Spiegel, D. Landolt, The role of passive oxide lms on the degra-dation of steel in tribocorrosion systems, Wear 225229 (1999) 10781087.

[20] Y. Birol, Ni- and Co-based superalloys as potential tool materials for thixo-forming of steels, in: Proc. 13th International ESAFORMConference onMaterialForming, Brescia, Italy, April 79, 2010.

[21] Y. Birol, Testing of a novel CrNiCo alloy for tooling applications in semi-solidprocessing of steels, Int. J. Mater. Form. 3 (2010) 6570.

[22] K. Bobzin, E. Lugscheider, M. Maes, P. Immich, Alumina PVD tool coatings forthe use in semi solid metal forming of steel, Solid State Phenomena 116117(2006) 704707.

[23] Y. Birol, Thermal fatigue testing of tooling materials for semi-solid processingof steels, Steel Res. Int. 80 (2009) 588592.

[24] Y. Birol, Effect of bulk die temperature on die cavity surface strains in thixo-forming of steels, Ironmak. Steelmak. 36 (2009) 397400.

[25] Y. Birol, A CrNiCo alloy as a potential tool material in semi-solid processing ofsteels, Steel Res. Int. 80 (2009) 165171.

[26] S. Muenstermann, K. Uibel, T. Tonnesen, R. Telle, Development of a self-heatingceramic tool for the thixoextrusion of high melting point alloys, Solid StatePhenomena 116117 (2006) 696699.

[27] R. Telle, S. Muenstermann, C. Beyer, Design, construction and performance ofsilicon nitride tool parts in steel thixoforming, Solid State Phenomena 116117(2006) 690695.

[28] HKashani, A. Amadeh, H.M. Ghasemi, Roomandhigh temperaturewear behav-iors of nickel and cobalt base weld overlay coatings on hot forging dies, Wear262 (2007) 800806.

[29] M.X. Yao, J.B.C. Wu, Y. Xie, Wear, corrosion and cracking resistance of someW- or Mo-containing stellite hardfacing alloys, Mater. Sci. Eng. A 407 (2005)234244.

[30] C. Navas, A. Conde, M. Cadenas, J. de Damborenea, Tribological properties oflaser clad

[31] B.F. LevinWear 181

[32] M.K. Ali, M617 alloy

[33] Y. Birol, Thermal fatigue testing of Inconel 617 and Stellite 6 alloys as toolingmaterials for thixoforming of steels, Mater. Sci. Eng. 527 (2010) 19381945.

[34] Y. Birol, Ni-based superalloy as a potential tool material for thixoforming ofsteels, Ironmak. Steelmak. 36 (2009) 555560.

[35] Y. Birol, Response to thermal cycling of tool Materials under steel thixoformingconditions (2010), Ironmak. Steelmak. 37 (2010) 4146.

[36] Y. Birol, The use of CrNiCo-based superalloy as die material in semi-solid pro-cessing of steels, Solid State Phenomena 141143 (2008) 289294.

[37] D. Schwam, J.F. Wallace, S. Bircenau, Die Materials for Critical Applications andIncreased Production Rates, DE-FC07-98ID13693, 2002.

[38] L.H.S. Lung, T. Heijkoop, The inuence of scale on friction in hot metal working,Wear 71 (1981) 93102.

[39] P.A. Munther, J.G. Lenard, The effect of scaling on interfacial friction in hotrolling of steels, J. Mater. Process. Technol. 88 (1999) 105113.

[40] O. Barrau, C. Boher, R. Gras, F. Rezai-Aria, Wear mechanisms and wear ratein a high temperature dry friction of AISI H11 tool steel: inuence of debriscirculation, Wear 263 (2007) 160168.

[41] ASM Handbook, Vol. 9: Metallography and Microstructures, ISBN 0871707063.[42] G.A. Fontalvo, C. Mitterer, The effect of oxide-forming alloying elements on the

high temperature wear of a hot work steel, Wear 258 (2005) 14911499.[43] F.H. Stott, M.P. Jordan, The effects of load and substrate hardness on the devel-

opment and maintenance of wear-protective layers during sliding at elevatedtemperatures, Wear 250 (2001) 391400.

[44] F.H. Stott, High-temperature sliding wear of metals, Tribol. Int. 35 (2002)489495.

[45] O. Joos, C. Boher, C. Vergne, C. Gaspard, T. Nylen, F. Rezai-Aria, Assessment ofoxide scales inuence on wear damage of HSM work rolls, Wear 263 (2007)198206.

[46] A. Molinari, M. Pellizzari, A. Biggi, G. Corbo, A. Tremea, Primary carbides in spincast HSS for hot rolls and their effect on the oxidation behaviour, in: Proc. 6thInt. Tooling Conference, Karlstadt University, September, 2002, pp. 365377.

[47] D.J. Stephenson, J.R. Nicholls, P. Hancock, Particle-surface interactions duringthe erosion of a gas turbine material (MarM002) by pyrolytic carbon particles,Wear 111 (1986) 1529.

[48] I.G. Wright, V. Nagarajan, J. Stringer, Observations on the role of oxide scales inhigh-temperature erosioncorrosion of alloys, Oxid. Met. 25 (1986) 175199.

[49] G.Y. Lai, High-temperature Corrosion of Engineering Alloys, ASM, MaterialsPark, OH, 1997.

[50] H. Kashani, M. Sadeghi Laridjani, A. Amadeh, M. Khodagholi, S. Ahmadzadeh,The inuence of volumetric dilution on the strain induced gamma epsilonmartensitic transformation in GTAW processed CoCrMo alloy, Mater. Sci.Eng. A478 (2008) 3842.

[51] F.H. Stott, D.S. Lin, G.C. Wood, C.W. Stevenson, The tribological behaviour ofkel an(Febru

edvepertie23 (20Stellite 6 coatings on steel substrates, Surf. Eng. 22 (2006) 2634., J.N. DuPont, A.R. Marder, Weld overlay coatings for erosion control,183 (1995) 810820..S.J. Hashmi, B.S. Yilbas, Fatigue properties of the refurbished INCO-

, J. Mater. Process. Technol. 118 (2001) 4549.

nic36

[52] A. MproA 5d nickel-chromium alloys at temperatures from 20 to 800 C, Wearary (2)) (1976) 147174.deva, J. Bergstrm, S. Gunnarsson, J. Andersson, High-temperatures andmicrostructural stability of hot-work tool steels,Mater. Sci. Eng.09) 3946.

High temperature sliding wear behaviour of Inconel 617 and Stellite 6 alloysIntroductionExperimentalResults and discussionConclusionsAcknowledgementsReferences