İÇTEN YANMALI MOTORLARDA ÖSTENİTİK EGZOZ SUPAPLARININ YÜKSEK SICAKLIK AŞINMA MEKANİZMALARININ TESPİTİ

Abstract

Bu çalışmada 21-4N (%21 Cr, %9 Mn ve %3.88 Ni temel bileşenli alaşım) egzoz supap malzemesinin PL12 alaşımlı beyaz temper dökme demir baga malzemesi karşısında yüksek sıcaklıktaki aşınma davranışı incelenmiştir. Egzoz supap-baga ikilisinin aşınma testleri için özel olarak geliştirilmiş bir tribometre kullanılarak 25 ℃, 350 ℃, 550 ℃’de ve 20 N yük altında testler yapılmıştır. Yapısal ve termodinamik analizler ile 21-4N supap - PL12 baga ikilisinin ara yüzeyinde gerçekleşen yüksek sıcaklık aşınma mekanizması literatürde ilk kez incelenmiştir. Aşınma sırasında uygulanan lokal basınç ve sıcaklık artışı ile spinel oksit yapılardan oluşan, aşınmaya karşı koruyucu bir tabakanın 21-4N yüzeyinde oluştuğu görülmüştür. Bu oluşan tribofilm yüksek sıcaklıklarda 21-4N supap malzemesinin PL12 baga karşısında hacimsel aşınma kaybının azalmasına neden olmuştur. Ayrıca sıcaklığa bağlı oluşan/çözülen karbür ve karbonitrür fazları da termodinamik olarak hesaplanmıştır. Sıcaklık artışı ile pinin mukavemeti azalırken, 21-4N supap malzemesinin 900°C’ye kadar kararlılık gösteren çökelti fazlarından dolayı mekanik özelliklerini koruduğu ve aşınma direncinin arttırdığı tespit edilmiştir.

Keywords

• Aşınma
• Supap
• Baga
• İçten Yanmalı Motor
• Östenitik

INVESTIGATION OF HIGH TEMPERATURE WEAR MECHANISMS OF AUSTENITIC EXHAUST VALVES IN INTERNAL COMBUSTION ENGINES

Abstract

In this study, high temperature wear behaviour of 21-4N (%21Cr, %9Mn, %3.88 Ni based alloying elements) exhaust valve material against PL12 alloyed white cast iron seat insert material was investigated. The sliding wear tests were conducted at 25℃, 350℃, 550℃ and under 20N load using a high temperature tribometer which was designed for the wear tests of valve-seat insert couples. By means of structural and thermodynamic analysis, the high temperature wear mechanism that takes place at the interface of 21-4N-PL12 was investigated for the first time. It was determined that the spinel oxide structures formed a tribolayer on the surface 21-4N by the effects of local pressure and high temperature during the sliding. This causes a decrease in volumetric wear loss of 21-4N against PL12 at high temperatures. Additionally, the formed carbide and nitride phases were calculated thermodynamically. While the strength of pin decreases with increasing temperature, 21-4N maintains its mechanical properties and wear resistance increases since the precipitate phases are stable up to 900° C

Keywords

• Wear
• Valve
• Valve Seat Insert
• Internal Combustion Engine
• Austenite

References

1. Ahlawat, A., Sathe, V.G., Reddy, V.R., Gupta, A. , Mossbauer, 2011. Journal of Magnetism and Magnetic Materials, Raman and X-ray diffraction studies of superparamagnetic NiFe2O4 nanoparticles prepared bysol–gel auto-combustion method, 323, 2049–2054.
2. Chin K.J. , Zaidi, H. , Mathi, T. , 2005. Wear, Oxide film formation in magnetized sliding steel/steel contact—analysis of the contact stress field and film failure mode, 259, 477–481.
3. Choi,J., Seok, C.S., Park, S., Kim, G., 2019. Journal of Materials Research and Technology, Effect of high-temperature degradation onmicrostructure evolution and mechanicalproperties of austenitic heat-resistant steel, 8, (2), 2011-2020.
4. D’Ippolito, V. , Andreozzi, G.B. , Bersani, D. , Lottici, P. P. , 2015. Journal of Raman Spectroscopy, Raman fingerprint of chromate, aluminate and ferrite spinels, 46, 1255-1264.
5. Faria, D. L. A. , Silva, S. V. , Oliveira, M. T., 1997. Journal of Raman Spectroscopy, Raman Microspectroscopy of Some Iron Oxides and Oxyhydroxides, 28, 873-878.
6. Farrow, R.L. , Benner, R.E. , Nagelberg, A.S. , Mattern, P.L., 1980. Thin Solid Films, Characterization of surface oxides by Raman spectroscopy, 73, 353-358.
7. Hosterman, B.D., 2011. PhD thesis, Raman spectroscopic study of solid solution spinel oxides.
8. Inman, I.A. , 2003. PhD. Thesis, Compacted oxide layer formation under conditions of limited debris retention at the wear interface during high temperature sliding wear of superalloys.

9. Jiang, J. , Stott, F.H. , Stack, M.M., 1998. Tribol. Int., The role of triboparticulates in dry sliding wear, 31, 245–256.
10. Julien, C.M. , Massot, M. , Poinsignon, C., 2004. Spectrochimica Acta Part A, Lattice vibrations of manganese oxides Part I. Periodic structures 60, 689–700.
11. Kato, H. , Komai, K., 2007. Wear, Tribofilm formation and mild wear by tribo-sintering of nanometer-sized oxide particles on rubbing steel surfaces, 262, 36–41.
12. Kesavan, D. , Done, V. , Sridhar, M.R., Billig, R. , Nelias, D., 2016. Tribology International, High temperature fretting wear prediction of exhaust valve material, 100, 280–286.
13. Khan, M.I. , Khan, M.A. , Shakoor, A. A., 2018. Engineering Failure Analysis, failure analysis of the exhaust valve from a heavy duty natural gas engine, 85, 77-88.
14. Kim, D.K. , Kim, D.Y. , Ryu, S.H. , Kim, D.J., 2001. Journal of Materials Processing Technology, Application of nimonic 80A to the hot forging of an exhaust valve head, 103, 148-152.
15. Kim, J. H., Hwang, Il S., 2005. Nuclear Engineering and Design, Development of an in situ Raman spectroscopic system for surface oxide films on metals and alloys in high temperature water, 235, 1029–1040.
16. Kim, J. , Choi, K.J. , Bahn, C.B. , Kim, J. H., 2014. Journal of Nuclear Materials, In situ Raman spectroscopic analysis of surface oxide films on Ni-base alloy/low alloy steel dissimilar metal weld interfaces in high-temperature water, 449, 181–187.
17. Li, W., Yu, M., Li, J., Zhang, G., Wang, S., 2009. Materials and Design, Characterizations of 21-4N to 4Cr9Si2 stainless steel dissimilar joint bonded by electric-resistance-heat-aided friction welding, 30, 4230–4235.
18. Li, Y. , Ji, H. , Cai, Z. , Tang, X. , Li, Y. , Liu, J., 2019. Materials, Comparative study on constitutive models for 21-4N heat resistant steel during high temperature deformation, 12, 1893.
19. Mascarenhas, L. A.B. , Gomes, J.O. , Beal, V.E. , Portela, A.T. , Ferreira, C.V. , Barbosa, C.A., 2015. Wear, Design and operation of a high temperature wear test apparatus for automotive valve materials, 342-343, 129–137.
20. Ootani, T. , Yahata, N. , Fujiki, A. Ehira, , A., 1995. Wear, Impact wear characteristics of engine valve and valve seat insert materials at high temperature (impact wear tests of austenitic heat-resistant steel SUH36 against Fe-base sintered alloy using plane specimens), 188,175-184.
21. Pearson, S.R. , Shipway, P.H., Abere, J.O., Hewitt, R.A.A., 2013. Wear, The effect of temperature on wear and friction of a high strength steel in fretting, 303, 622–631.
22. Pierce, D., Haynes, A., Hughes, J., Graves, R., Maziasz, P., Muralidharan, G., Shyam, A., Wang, B., England, R. Daniel, C., 2019. Progress in Materials Science, High temperature materials for heavy duty diesel engines: Historical and future trends, 103, 109–179.
23. Ramalho, A. , Kapsa, Ph. , Bouvard, G. , Abry, J.-C. , Yoshida, T. , Charpentier, M. , Bourgeois, M., 2009. Wear, Effect of temperatures up to 400 ◦C on the impact-sliding of valve-seat contacts, 267, 777–780.
24. Ristic´,M. , Music´, S., Popovic´ , S., Dragcˇevic´, D., Marciuš, M., Ivanda, M. , 2013. Journal of Molecular Structure, Synthesis and long-term phase stability of Mn3O4 nanoparticles, 1044, 255–261.
25. Rybiak, R. , Fouvry, S. , Bonnet, B. , 2010. Wear, Fretting wear of stainless steels under variable temperature conditions: Introduction of a ‘composite’ wear law, 268, 413–423.
26. Silva, G.C. , Almeidab, F.S., Dantasa, M.S.S. , Ferreirab, A.M.,Ciminellia, V.S.T., 2013. Spectrochimica Acta Part A, Raman and IR spectroscopic investigation of As adsorbed on Mn3O4 magnetic Composites, 100, 161–165.
27. Slatter, T. , Taylor, H. , Lewis, R. , King, P., 2009. Wear, The influence of laser hardening on wear in the valve and valve seat contact, 267, 797–806.
28. Stott, F.H. , Wood, G.C. , 1978. Tribol. Int. , The influence of oxides on the friction and wear of alloys, 11, 211–218.
29. Stott, F.H. , Glascott, J. , Wood, G.C., 1985. Wear, The sliding wear of commercial Fe–12%Cr alloys at high temperature, 101, 311–324.
30. Wang, Y. S. , Schaefer, S. K. , Bennett, C. , Barber, G. C., 1995. Society of Automotive Engineers (SAE International), Technical Paper Series, Wear Mechanisms of Valve Seat and Insert in Heavy Duty Diesel Engine, 952476.
31. Wang, Z., Saxena, S.K. , Lazor, P., O’Neill, H.S.C., 2003. Journal of Physics and Chemistry of Solids, An in situ Raman spectroscopic study of pressure induced dissociation of spinel NiCr2O4, 64, 425–431.
32. Zhang, S., Jin, X., Zhong, W., Xu, A., Zhou, X., Ma, L., and Qui, Z., 2012. Proc. Inst. Mech. Eng., Part J, Investigation on Tribological Behaviour of Diesel Engine Exhaust Valve Dry Sliding Against Valve Seat, 227 (7), 798–805.
33. Zheng, Z. , 2019. Metals, Experimental study on cross wedge rolling of 21-4N heat resistant steel, 9, 39.