The Paton Welding Journal, 2013, №12



2013 №12 (02)

2013 №12 (04)

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The Paton Welding Journal, 2013, #12, 16-21 pages

INFLUENCE OF STRUCTURAL PARAMETERS ON MECHANICAL PROPERTIES OF R6M5 STEEL UNDER THE CONDITIONS OF STRENGTHENING SURFACE TREATMENT

L.I. MARKASHOVA, Yu.N. TYURIN, O.V. KOLISNICHENKO, M.L. VALEVICH and D.G. BOGACHEV

E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine. 11 Bozhenko Str., 03680, Kiev, Ukraine. E-mail: office@paton.kiev.ua
 
 
Abstract
The work is devoted to investigation of structural-phase changes in surface layers of high-speed steel R6M5 after strengthening pulsed-plasma surface treatment in various modes and influence of forming structure parameters on tool performance. As a result of comprehensive investigations and calculation-analytical prediction of strength properties, fracture toughness coefficient and crack resistance of surfaces, strengthened in various technological modes, it was established that optimum properties of subsurface layers are ensured at recommended modes of pulsed-plasma surface treatment, increasing the total strength level by 25%, compared with base metal due to refinement of grain structure (by 1.5 to 2 times), increase of the contribution of substructural, grain, dislocation and dispersion strengthening mechanism. Here, the level of local inner stresses in the treated layer is equal to ~0.018 to 0.44 of the theoretical strength of material that is not dangerous in terms of crack formation, because of the absence of abrupt gradients as to inner stresses and uniformly increased dislocation density (10¹¹-2×10¹¹ cm^-2) compared to base metal. It is shown that at a significant strengthening of treated layers of high-speed steel, the value of fracture toughness coefficient is by 15 % higher compared to base metal. Thus, application of recommended modes of pulsed-plasma surface treatment leads to modifying the structural-phase state of the surface layer and improvement of its mechanical properties. 31 Ref., 9 Figures.
 
 
Keywords: pulsed-plasma treatment, surface, high-speed steel R6M5, light microscopy, electronic microscopy, analytical assessment, strength, fracture toughness, crack resistance
 
 
Received:                06.06.13
Published:               28.12.13
 
 
References
1. Mironov, V.M., Mazanko, V.F., Gertsriken, D.S. et al. (2001) Mass transfer and phase formation under pulse effects. Samara: Samara GU.
2. Burakov, V.V., Fedoseenko, S.S. (1983) Formation of structures of higher wear resistance in laser hardening of metal-working tools. Metallovedenie i Term. Obrab. Metallov, 5, 16-17.
3. Volkhin, S.A. (1990) Influence of structure of tool steels after hardening and tempering on parameters of laser-hardened layers. Sudostroit. Promyshlennost, 23, 44-48.
4. Sobusyak, T., Sokolov, K.N. (1991) Effect of laser heat treatment on structure and properties of high-speed steel. Problemy Mashinostr. i Avtomatiz., 5, 45-53.
5. Kikin, P.Yu., Pchelintsev, A.I., Rusin, E.E. (2003) Increase in heat- and wear resistance of high-speed steels by shock-wave action. Fizika i Khimiya Obrab. Materialov, 5, 15-17.
6. Gureev, D.M., Lamtin, A.P., Chulkin, V.N. (1990) Influence of pulsed laser radiation on state of cobalt interlayer of hard alloys. Ibid., 1, 51-54.
7. Babushkin, V.B. (1990) Peculiarities of structure formation in high-speed and high-chromium die steels in laser heating. Izvestiya Vuzov. Chyorn. Metallurgiya, 4, 68-70.
8. Markashova, L.I., Kolisnichenko, O.V., Valevich, M.L. et al. (2012) Structure and mechanical properties of tools from high-speed steel in pulse-plasma surface treatment. In: Building, materials science, machine-building: Transact. Issue 64, 211-220. Dnepropetrovsk: GVUZ PGASA.
9. Markashova, L.I., Tyurin, Yu.N., Kolisnichenko, O.V. et al. (2012) Analytical estimation of structural parameter contribution into change of mechanical properties of high-speed steel after pulse-plasma surface treatment. In: Proc. of 6th Int. Conf. on Mathematical Modelling and Information Technologies in Welding and Related Processes. Kiev: PWI, 49-53.
10. Cordier-Robert, C., Crampon, J., Foct, J. (1998) Surface alloying of iron by laser melting: Microstructure and mechanical properties. Surface Eng., 14(5), 381-385.
11. Chudina, O.V., Borovskaya, T.M. (1994) Strengthening of steel surface by chemical-heat post treatment. Metallovedenie i Term. Obrab. Metallov, 12, 2-7.
12. Chudina, O.V. (1997) Surface alloying of iron-carbon alloys with application of laser heating. Ibid., 7, 11-14.
13. Ritter, U., Kahrmann, W., Kurpfer, R. et al. (1992) Laser coating proven in practice. Surface Eng., 8(4), 381-385.
14. Lugscheider, E., Boplender, H., Krappitz, H. (1992) Laser cladding of paste bound hardfacing alloys. Ibid., 7(4), 341-344.
15. Navara, E., Bengsston, B., Li, W.B. et al. (1984) Surface treatment of steel by laser transformation hardening. In: Proc. of 3rd Int. Congr. on Heat Treatment of Materials (Shanghai, 7-11 Nov. 1983). Shangri: Metal Society, 40-44.
16. Tverdokhlebov, T.N., Diachenko, V.S. (1980) Influence of laser treatment conditions on resistance of high-speed steel tools. In: Cutting equipment and tools. Moscow: Mashinostroenie.
17. Hancock, I.M. et al. (1988) Laser modification of high-speed steel. In: Proc. of Int. Conf. on Heat Treatment (London, 11-15 May 1987). London: Metal Society, 189-195.
18. Tyurin, Yu.N., Zhadkevich, M.L. (2008) Plasma hardening technologies. Kiev: Naukova Dumka.
19. Suzuki, H. (1967) About yield strength of polycrystalline metals and alloys. In: Structure and mechanical properties of metals. Moscow: Metallurgiya.
20. Eshby, M.F. (1972) On Orowan stress. In: Physics of strength and plasticity. Moscow: Metallurgiya.
21. Goldshtejn, M.I., Litvinov, V.S., Bronfin, B.M. (1986) Metallophysics of high-strength alloys. Moscow: Metallurgiya.
22. Conrad, H. (1973) Model of strain hardening for explanation of size grain effect on flow metal stress. In: Ultrafine grains in metals. Ed. by L.K. Gordienko. Moscow: Metallurgiya.
23. Armstrong, R.V. (1973) Strength properties of metals with ultrafine grains. Ibid. Moscow: Metallurgiya.
24. Petch, N.J. (1953) The cleavage strength of polycrystalline. J. Iron and Steel Inst., 173(1), 25-28.
25. Orowan, E. (1954) Dislocation in metals. New York: AIME.
26. Ashby, M.F. (1983) Mechanisms of deformation and fracture. Adv. Appl. Mech., 23, 118-177.
27. Kelly, A., Nickolson, R. (1966) Dispersion hardening. Moscow: Metallurgiya.
28. Ebelling, R., Ashby, M.F. (1966) Yielding and flow of two phase copper alloys. Phil. Mag., 13(7), 805-809.
29. Romaniv, O.N. (1979) Fracture toughness of structural steels. Moscow: Metallurgiya.
30. Koneva, N.A., Lychagin, D.V., Teplyakova, L.A. et al. (1986) Dislocation-disclination substructures and hardening. In: Theoretical and experimental study of disclinations. Leningrad: LFTI.
31. Conrad, H. (1963) Effect of grain size on the lower yield and flow stress of iron and steel. Acta Met., 11, 75-77.
- ?/>H????!ass=MsoNormal>34. Thawari, G., Sundarararjan, G., Joshi, S.V. (2003) Laser surface alloying of medium carbon steel with SiC(P). Thin Solid Films, 423, 41-53.
 
35. Dobrzanski, L.A., Bonek, M., Labisz, K. (2013) Effect of laser surface alloying on structure of a commercial tool steel. J. Microstructure and Mater. Properties, 8, Issue 1/2, 27-37.
36. Lazko, G.V. (2009) Peculiarities of structure formation and ways to improve properties of barrier layers on corrosion-resistant steels, formed by laser alloying: Syn. of Thesis for Cand. of Techn. Sci. Degree. Donetsk: DNTU.
37. Kalashnikova, M.S., Belova, S.A., Mazepina, Yu.A. et al. (2003) Corrosion resistance of structural steel surface layers after laser treatment. Fizika i Khimiya Obrab. Materialov, 2, 34-39.
38. Haferkamp, H., Bach, F.-W., Gerken, J. (1995) Laserstrahllegieren plasmagesprittzer Molybdanschichten in Stahloeberflachen zur Erhoehung des Verschleisswiderstandes. Metall, 49, Issue 7/8, 516-522.
39. Zhostik, Yu.V. (1998) Study of impact wear of shearing dies and increase in their resistance due to laser alloying: Syn. of Thesis for Cand. of Techn. Sci. Degree. Bryansk: BGITA.
40. Inyutin, V.P., Kolesnikov, Yu.V., Zhostik, Yu.V. (1986) Effect of laser boronizing on contact deformations of steel 45 under impact-cyclic loading. Elektr. Tekhnika. Series 6: Materials, 215, Issue 4, 77-78.
41. Klocke, F., Rozsnoki, L., Celiker, T. et al. (1996) New developments in surface technology: Laser alloying using Mo/VC and Mn. CIRP Annals Е Manufact. Technology, 45, Issue 1, 179-182.
42. Klocke, F., Auer, O., Hamers, M. (1998) Verschleissreduzierung bei Schmiedewerkzeugen. Maschinenmarkt, 104, Issue 34, 32-33.
43. Klocke, F., Auer, O., Hamers, M. (2002) Verschleissschutz von Warmumformwerkzeugen. VDI-Z Integrierte Produktion Special, 2, 67-69.
44. Klocke, F., Auer, O., Hamers, M. (2000) Laser scan help protect tools. Quelle Diecasting World, 6, 18-21.
45. Kastro, V.A. (2012) Development of technology for laser thermal strengthening and alloying of steels for power machine building with the purpose of increase of service life of items: Syn. of Thesis for Cand. of Techn. Sci. Degree. Nizhny Novgorod: R.E. Alekseev NGTU.
46. Kastro, V.A., Gavrilov, G.N., Brauer, I. et al. (2011) Peculiarities of steel structure formation in laser thermal cycle. Zagotovit. Proizvod. v Mashinostroenii, 12, 38-41.
47. (1997) Werkzeugehaerten senkt die Kosten. http:// www.archiv.fraunhofer.de/archiv/alte %20jahresbe richte/pflege.zv.fhg.de/german/publications/jahre s-ber/jb1997/f_oberfl.htm1
48. Gavrilov, G.N. (2000) Development and mastering of technologies for surface thermal strengthening and surfacing of metallic materials by laser radiation: Syn. of Thesis for Dr. of Techn. Sci. Degree. Nizhny Novgorod: NGTU.
49. Gavrilov, G.N., Gorshkova, T.A., Fedoseev, V.B. (1997) Influence of thermochemical effect on laser alloying process. Izvestiya Inzh.-Tekhnolog. Akad. Chuvash. Resp.: Joint Sci. J., 3/4, 118-121.
50. Gavrilov, G.N., Gorshkova, T.A., Dubinsky, V.N. (1998) Study of wear resistance of steel 45 after laser alloying. Ibid., 1/2, 122-125.

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