Application of Scanning Electron Microscopy and EDS Microanalysis for Microstructural Investigation of Hypoeutectoid Steel

Abstract:

The results of a microstructure, energy dispersive X-ray spectroscopy (EDS) analysis and hardness investigations of the hypoeutectoid steels with 1% Ni, imitating by its chemical composition toughening steels, are presented in the paper. According to PN-EN 10027 standard this steel should have a symbol 37NiMo4-3.The kinetic of phase transformation of undercooled austenite of investigated steel was presented on CCT diagram (continuous cooling transformation). The CCT diagram of tested steel is characterized in that the curves of beginning of the diffusion transitions form a letter "C" and are not separated from bainitic transformation by the stability range of the undercooled austenite.The EDS analysis performed for the selected cooling rates did not reveal any changes in the distribution of alloying elements of hypoeutectoid 37NiMo4-3 steel. However, these studies, from the point of view of the effect of alloying elements (acting jointly) are only the preliminary assessment analysis (beginning) of the impact of the chemical composition gradient in micro-scale in iron-based alloys.

• Periodical: Solid State Phenomena (Volume 231)
• Pages: 125-131
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.231.125
• Online since: June 2015
• Authors: Edyta Rożniata*, Dariusz Zasada
• Keywords: CCT Diagram, EDS Analysis, Heat Treatment, Hypoeutectoid Steel, Microstructure

References

[1] J.C. Anderson, K.D. Leaver, R.D. Rawlings, P.S. Leevers, Materials Science for Engineers, fiftieth ed., Nelson Thornes Ltd, New York, (2003).

[2] J. Krawczyk, E. Rożniata, J. Pacyna, The influence of hypereutectoid cementite morphology upon fracture toughness of chromium-nickel-molybdenum cast steel of ledeburite class, J. Mater. Process. Tech. 162–163 (2005) 336-341.

DOI: 10.1016/j.jmatprotec.2005.02.097

[3] Th. Sourmail, V. Smanio, Low temperature kinetics of bainite formation in high carbon steels. Acta Mater. 61 (2013) 2639-2648.

DOI: 10.1016/j.actamat.2013.01.044

[4] E. Rożniata, R. Dziurka, Analysis of the microstructure of 37MnMo6-3 hypoeutectoid steel, Arch. Mater. Sci. Eng. 58 (2012) 125-129.

[5] E. Rożniata, The microstructures and energy dispersive spectroscopy analysis of a hypoeutectoid steels with 1 % Cr, Arch. Metall. Mat. 58 (2013) 1253-1259.

DOI: 10.2478/amm-2013-0144

[6] R. Dąbrowski, R. Dziurka, Tempering temperature effects on hardness and impact toughness of 56NiCrMo7 steel, Arch. Metall. Mat. 56 (2011) 5-11.

DOI: 10.2478/v10172-011-0001-4

[7] J. Pacyna, R. Dąbrowski, G. Zając, Effect of carbon content on the fracture toughness of Ni-Cr-Mo steels, Arch. Metall. Mat. 53 (2008) 803-807.

[8] M.F. Ashby, D.R.H. Jones, Engineering Materials 2, fourth ed., Oxford, (2013).

[9] P. Bała, The kinetics of phase transformations during tempering of tool steels with different carbon content, Arch. Metall. Mat. 54 (2009) 491-498.