Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-23T12:48:28.507Z Has data issue: false hasContentIssue false

Effect of electric current pulses on the microstructure and niobium carbide precipitates in a ferritic-pearlitic steel at an elevated temperature

Published online by Cambridge University Press:  15 September 2015

Alireza Rahnama*
Affiliation:
Warwick Manufacturing Group (WMG), International Digital Laboratory (IDL), University of Warwick, Coventry CV4 7Al, United Kingdom
R.S. Qin
Affiliation:
Department of Engineering and Innovation, The Open University, Walton Hall, Milton Keynes MK7 6AA, Buckinghamshire, United Kingdom
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Niobium is an important alloying element in steels. In the present work an effort has been made to investigate the effect of electropulsing on the niobium carbide (NbC) at an elevated temperature (800 °C). The results show that the electropulsing treatment can generate an evenly distributed NbC by decreasing the kinetics barriers for precipitation. It has been also found that a semitransformed pearlite structure forms in such a way that the grains are oriented toward a direction parallel to that of the electric current flow. Furthermore, the electropulsed sample benefits from refined grain size. This is thought to be due to the electropulse-enhanced nucleation rate. Tensile testing has been carried out to compare the properties of electropulsed sample with that of without electropulsing. The results show that the sample with treatment has greater yield strength and ultimate tensile stress while its elongation is only 1% less that of the unelectropulsed samples. The improved mechanical properties of the sample with pulsing are attributed to its finer grain sizes as well as the elimination of precipitation free zones caused by the electropulsing treatment.

Type
Articles
Copyright
Copyright © Materials Research Society 2015 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Ye, X., Lingsheng, W., Tse, Z.T.H., Tang, G., and Song, G.: Effects of high-energy electro-pulsing treatment on microstructure, mechanical properties and corrosion behaviour of Ti-6Al4V alloy. Mater Sci. Eng., C 49, 851860 (2015).Google Scholar
Zhang, X.F. and Qin, R.S.: Controlled motion of electrically neutral microparticles by pulsed direct current. Sci. Rep. 5, 10162 (2015).Google Scholar
Guan, L., Tang, G.Y., and Chu, P.K.: Recent advances and challenges in electroplastic manufacturing processing of metals. J. Mater. Res. 25, 12151224 (2010).Google Scholar
Barnak, J.P., Sprecher, A.F., and Conrad, H.: Colony (grain) size reduction in eutectic Pb–Sn castings by electropulsing. Scr. Metall. Mater. 32, 879884 (1995).Google Scholar
Conrad, H.: Effects of electric current on solid state phase transformations in metals. Mater Sci Eng., A 287, 227237 (2000).Google Scholar
Zhou, Y.Z., Qin, R.S., Xiao, S.H., He, G., and Zhou, B.: Reversing effect of electropulsing on damage of 1045 steel. J. Mater. Res. 15, 10561061 (2000).Google Scholar
Onodora, Y., Sakuma, A., and Hirano, K.I.: Current dependence of the retardation of precipitation by direct-current stress in AI-3.3 at % Mg. J. Mater. Sci. 28, 38353838 (1993).CrossRefGoogle Scholar
Onodora, Y., Maruyama, J.I., and Hirano, K.I.: Retardation of the precipitation reaction by d.c. stress in an A1-12.5 wt. % Zn alloy. J. Mater. Sci. 12, 11091114 (1977).Google Scholar
Fujita, N. and Bhadeshia, H.K.D.H.: Modelling precipitation of niobium carbide in austenite: Multicomponent diffusion, capillarity, and coarsening. Mater. Sci. Technol. 17, 403408 (2001).Google Scholar
Yan, P. and Bhadeshia, H.K.D.H.: Austeniteferrite transformation in enhanced niobium, low carbon steel. Mater. Sci. Technol. 31, 10661076 (2015).Google Scholar
Rahnama, A. and Qin, R.S.: Electropulse-induced microstructural evolution in a ferriticpearlitic 0.14% C steel. Scr. Mater. 96, 1720 (2015).Google Scholar
Rahnama, A. and Qin, R.S.: The effect of electropulsing on the interlamellar spacing and mechanical properties o fa hot-rolled 14 wt.% carbon steel. Mater. Sci. Eng., A 627, 145152 (2015).Google Scholar
Dolinsky, Y. and Elperin, T.: Thermodynamics of phase transitions in current carrying conductors. Phys. Rev. B 47, 1477814785 (1993).CrossRefGoogle ScholarPubMed
Lu, W.J., Zhang, X.F., and Qin, R.S.: Stability of precipitates under electropulsing in 316L stainless steel. Mater. Sci. Technol, in press, doi: 10.1179/1743284714Y.0000000743.CrossRefGoogle Scholar
Wang, X.L., Wang, X.L., Guo, J.D., Wang, Y.M., Wu, X.Y., and Wang, B.Q.: Segregation of lead in Cu–Zn alloy under electric current pulses. Appl. Phys. Lett. 89, 061910 (2006).Google Scholar
Liu, Y., Fan, J., Zhang, H., Jin, W., Dong, H., and Xu, B.: Recrystallization and microstructure evolution of the rolled Mg–3Al–1Zn alloy strips under electropulsing treatment. J. Alloys Compd. 622, 229235 (2015).Google Scholar
Zheng, Y.S., Tang, G.Y., Kuang, J., and Zheng, X.P.: Effect of electropulsing on solid solution treatment of 6061 aluminium alloy. J. Alloys Compd. 615, 849853 (2014).Google Scholar
Qin, R.S. and Zhou, B.L.: Exploration on the fabrication of bulk nanocrystalline material by direct nanocrystallizing method II theoritical calculation of grain size of metals solidified under electropulsing. Chin. J. Mater. Res. 11, 6972 (1997).Google Scholar
Conrad, H., Karam, N., and Mannan, S.: Effect of electric current pulses on the recrystallization of copper. Scr. Mater. 17, 411416 (1983).Google Scholar
Xiao, S.H., Zhou, Y.Z., Guo, J.D., Wu, S.D., Yao, G., Li, S.X., He, G.H., and Zhou, B.L.: The effect of high current pulsing on persistent slip bands in fatigued copper single crystals. Mater. Sci. Eng., A 332, 351355 (2002).Google Scholar
Qin, R.S., Samuel, I., and Bhowmik, A.: Electropulse-induced cementite nanoparticle formation in deformed pearlitic steels. J. Mater. Sci. 46, 28382842 (2011).Google Scholar
Jiang, Y.B., Tang, G.Y., Shek, C.H., Zhu, Y.H., and Xu, Z.H.: On the thermodynamics and kinetics of electropulsing induced dissolution of β and Mg17Al12 phase in an aged Mg–9Al–1Zn alloy. Acta Mater. 57, 47974808 (2009).CrossRefGoogle Scholar
Ho, P.S. and Kwo, T.: Electromigration in metals. Rep. Prog. Phys. 52, 301348 (1989).Google Scholar