Understanding the tempering behavior of medium carbon steels is mandatory if their mechanical properties are to be improved. For an optimal technology to be developed for this purpose, a substantial experimental basis is needed to extract quantitative information on the microstructure of the tempered material. This paper reports on the characterization of microstructural changes induced by tempering in medium-carbon steels alloyed with Si, Cr, Cu, and Mn using state-of-the-art experimental techniques. Complementarities among these techniques are highlighted. The evolution of transition carbides, cementite, and copper precipitates is described using data from X-ray diffraction, small and ultra-small angle neutron diffraction, transmission electron microscopy, and dilatometry observation. The effects of silicon, chromium, and copper on the mechanism of carbide and copper precipitation are discussed. The considerable changes found in the size and volume of copper precipitates correlate well with the difference in the yield stress between tempered steels with and without copper.

COMTES FHT a s Prumyslova 995 334 41 Dobrany Czech Republic

Nuclear Physics Institute Czech Academy of Sciences 250 68 Řež Czech Republic

Zobrazit více v PubMed

Jirková H., Kučerová L., Mašek B. The Effect of Chromium on Microstructure Development During Q-P Process. Mater. Today Proc. 2015;2:S627–S630. doi: 10.1016/j.matpr.2015.07.362. DOI

Nam W.J., Choi H.C. Effect of Si on mechanical properties of low alloy steels. Mater. Sci. Technol. 1999;15:527–530. doi: 10.1179/026708399101506238. DOI

Černý I., Mikulová D., Sís J., Mašek B., Jirková H., Malina J. Fatigue properties of a low alloy 42SiCr steel heat treated by quenching and partitioning process. Procedia Eng. 2011;10:3310–3315. doi: 10.1016/j.proeng.2011.04.546. DOI

Morra P.V., Böttger A.J., Mittemeijer E.J. Decomposition of iron-based martensite: A kinetic analysis by means of differential scanning calorimetry and dilatometry. J. Therm. Anal. Calorim. 2001;64:905–914. doi: 10.1023/A:1011514727891. DOI

Jung M., Lee S.J., Lee Y.K. Microstructural and dilatational changes during tempering and tempering kinetics in martensitic medium-carbon steel. Metall. Mater. Trans. A Phys. Metall. Mater. Sci. 2009;40:551–559. doi: 10.1007/s11661-008-9756-2. DOI

Primig S., Leitner H. Separation of overlapping retained austenite decomposition and cementite precipitation reactions during tempering of martensitic steel by means of thermal analysis. Thermochim. Acta. 2011;526:111–117. doi: 10.1016/j.tca.2011.09.001. DOI

Jung J.-G., Jung M., Lee S.-M., Shin E., Shin H.-C., Lee Y.-K. Cu precipitation kinetics during martensite tempering in a medium C steel. J. Alloys Compd. 2013;553:299–307. doi: 10.1016/j.jallcom.2012.11.108. DOI

Jung J.-G., Jung M., Kang S., Lee Y.-K. Precipitation behaviors of carbides and Cu during continuous heating for tempering in Cu-bearing medium C martensitic steel. J. Mater. Sci. 2014;49:2204–2212. doi: 10.1007/s10853-013-7914-4. DOI

Wu Y.X., Sun W.W., Gao X., Styles M.J., Arlazarov A., Hutchinson C.R. The effect of alloying elements on cementite coarsening during martensite tempering. Acta Mater. 2020;183:418–437. doi: 10.1016/j.actamat.2019.11.040. DOI

Klemm-Toole J., Benz J., Vieira I., Clarke A.J., Thompson S.W., Findley K.O. Strengthening mechanisms influenced by silicon content in high temperature tempered martensite and bainite. Mater. Sci. Eng. A. 2020;786:139419. doi: 10.1016/j.msea.2020.139419. DOI

Peng J., Li K., Peng J., Pei J., Zhou C. The effect of pre-strain on tensile behaviour of 316L austenitic stainless steel. Mater. Sci. Technol. 2018;34:547–560. doi: 10.1080/02670836.2017.1421735. DOI

Leiva J.A.V., Morales E.V., Villar-Cociña E., Donis C.A., Bott I.D.S. Kinetic parameters during the tempering of low-alloy steel through the non-isothermal dilatometry. J. Mater. Sci. 2010;45:418–428. doi: 10.1007/s10853-009-3957-y. DOI

Strunz P., Saroun J., Mikula P., Lukás P., Eichhorn F. Double-Bent-Crystal Small-Angle Neutron Scattering Setting and its Applications. J. Appl. Crystallogr. 1997;30:844–848. doi: 10.1107/S0021889897001271. DOI

Keiderling U., Wiedenmann A. New SANS instrument at the BER II reactor in Berlin, Germany. Phys. B Condens. Matter. 1995;213–214:895–897. doi: 10.1016/0921-4526(95)00316-2. DOI

Wiedenmann A. Small Angle Neutron Scattering Investigations of Magnetic Nanostructures. In: Chatterji T., editor. Neutron Scattering from Magnetic Materials. Elsevier; Amsterdam, The Netherlands: 2006. pp. 473–520. DOI

Keiderling U. The new “BerSANS-PC” software for reduction and treatment of small angle neutron scattering data. Appl. Phys. A Mater. Sci. Process. 2002;74:s1455–s1457. doi: 10.1007/s003390201561. DOI

Šaroun J. Evaluation of double-crystal SANS data influenced by multiple scattering. J. Appl. Crystallogr. 2000;33:824–828. doi: 10.1107/S0021889899013370. DOI

Ishida K. Calculation of the effect of alloying elements on the Ms temperature in steels. J. Alloys Compd. 1995;220:126–131. doi: 10.1016/0925-8388(94)06002-9. DOI

Thompson S.W. Structural characteristics of transition-iron-carbide precipitates formed during the first stage of tempering in 4340 steel. Mater. Charact. 2015;106:452–462. doi: 10.1016/j.matchar.2015.05.030. DOI

He S.M., van Dijk N.H., Paladugu M., Schut H., Kohlbrecher J., Tichelaar F.D., van der Zwaag S. In situ determination of aging precipitation in deformed Fe-Cu and Fe-Cu-B-N alloys by time-resolved small-angle neutron scattering. Phys. Rev. B. 2010;82:174111. doi: 10.1103/PhysRevB.82.174111. DOI

Osamura K., Okuda H., Takashima M., Asano K., Furusaka M. Small-Angle Neutron Scattering Study of Phase Decomposition in Fe-Cu Binary Alloy. Mater. Trans. JIM. 1993;34:305–311. doi: 10.2320/matertrans1989.34.305. DOI

Breßler I., Kohlbrecher J., Thünemann A.F. SASfit: A tool for small-angle scattering data analysis using a library of analytical expressions. J. Appl. Crystallogr. 2015;48:1587–1598. doi: 10.1107/S1600576715016544. PubMed DOI PMC

Breßler I., Kohlbrecher J., Thünemann A.F. SASfit: A comprehensive tool for small-angle scattering data analysis. arXiv. 2015 (preprint)1506.02958 PubMed PMC

Cohen M. Self-Diffusion during Plastic Deformation. Trans. Japan Inst. Met. 1970;11:145–151. doi: 10.2320/matertrans1960.11.145. DOI

Buffington F.S., Hirano K., Cohen M. Self diffusion in iron. Acta Metall. 1961;9:434–439. doi: 10.1016/0001-6160(61)90137-7. DOI

Vasilyev A.A., Sokolov S.F., Kolbasnikov N.G., Sokolov D.F. Effect of alloying on the self-diffusion activation energy in γ-iron. Phys. Solid State. 2011;53:2194–2200. doi: 10.1134/S1063783411110308. DOI

Dlouhy J., Podany P., Dzugan J. Strengthening from Cu Addition in 0.2C-(1-2)Mn Steels during Tempering. Materials. 2019;12:247. doi: 10.3390/ma12020247. PubMed DOI PMC

Solt G., Frisius F., Waeber W.B., Tipping P. Irradiation induced precipitation in model alloys with systematic variation of Cu, Ni and P content: A small angle neutron scattering study. In: Kumar A., Gelles R.D., Nanstadt R., Little T., editors. Effects of Radiation on Materials: Sixteenth International Symposium. 2nd ed. ASTM International; Philadelphia, PA, USA: 1993. pp. 444–461.

Isheim D., Gagliano M.S., Fine M.E., Seidman D.N. Interfacial segregation at Cu-rich precipitates in a high-strength low-carbon steel studied on a sub-nanometer scale. Acta Mater. 2006;54:841–849. doi: 10.1016/j.actamat.2005.10.023. DOI

Kozeschnik E. Thermodynamic prediction of the equilibrium chemical composition of critical nuclei: Bcc Cu precipitation in α-Fe. Scr. Mater. 2008;59:1018–1021. doi: 10.1016/j.scriptamat.2008.07.008. DOI

Zmeko J. Bachelor’s Thesis. University of West Bohemia; Pilsen, Czech Republic: 2019. New Designed Spring Steel with High Strength Values.

Russell K.C., Brown L. A dispersion strengthening model based on differing elastic moduli applied to the iron-copper system. Acta Metall. 1972;20:969–974. doi: 10.1016/0001-6160(72)90091-0. DOI

Takeuchi T., Kuramoto A., Kameda J., Toyama T., Nagai Y., Hasegawa M., Ohkubo T., Yoshiie T., Nishiyama Y., Onizawa K. Effects of chemical composition and dose on microstructure evolution and hardening of neutron-irradiated reactor pressure vessel steels. J. Nucl. Mater. 2010;402:93–101. doi: 10.1016/j.jnucmat.2010.04.008. DOI

Kinetics of Austenite Decomposition in 54SiCr6 Steel during Continuous Slow Cooling Conditions

Effect of Cu Alloying on Mechanical Properties of Medium-C Steel after Long-Time Tempering at 500 °C

Effect of Double-Step and Strain-Assisted Tempering on Properties of Medium-Carbon Steel

Effect of 1.5 wt% Copper Addition and Various Contents of Silicon on Mechanical Properties of 1.7102 Medium Carbon Steel