Requirements for mechanical properties of steels are constantly increasing, and the combination of quenching and tempering is the method generally chosen for achieving high strength in medium carbon steels. This study examines the influence of various silicon contents from 1.06 to 2.49 wt% and the addition of copper (1.47 wt%) on the behavior of 1.7102 steel starting with the as-quenched state and ending with the tempered condition at the temperature of 500 °C. The microstructure was characterized by SEM and TEM, the phase composition and dislocation density were studied by XRD analysis, and mechanical properties were assessed by tensile and hardness testing, whereas tempered martensite embrittlement was assessed using Charpy impact test and the activation energy of carbide precipitation was determined by dilatometry. The benefit of copper consists in the improvement of reduction of area by tempering between 150 and 300 °C. The increase in strength due to copper precipitation occurs upon tempering at 500 °C, where strength is generally low due to a drop in dislocation density and changes in microstructure. The increasing content of silicon raises strength and dislocation density in steels, but the plastic properties of steel are limited. It was found that the silicon content of 1.5 wt% is optimum for the materials under study.

COMTES FHT a s Prumyslova 995 334 41 Dobrany Czech Republic

See more in PubMed

Sun C., Fu P.-X., Liu H.-W., Liu H.-H., Du N.-Y. Effect of Tempering Temperature on the Low Temperature Impact Toughness of 42CrMo4-V Steel. Metals. 2018;8:232. doi: 10.3390/met8040232. DOI

Jirková H., Mašek B., Wagner M.F.X., Langmajerová D., Kučerová L., Treml R., Kiener D. Influence of metastable retained austenite on macro and micromechanical properties of steel processed by the Q&P process. J. Alloys Compd. 2014;615:S163–S168. doi: 10.1016/j.jallcom.2013.12.028. DOI

Zhang K., Zhu M., Lan B., Liu P., Li W., Rong Y. The Mechanism of High-Strength Quenching-Partitioning-Tempering Martensitic Steel at Elevated Temperatures. Crystals. 2019;9:94. doi: 10.3390/cryst9020094. DOI

Shibata A., Nagoshi T., Sone M., Morito S., Higo Y. Evaluation of the block boundary and sub-block boundary strengths of ferrous lath martensite using a micro-bending test. Mater. Sci. Eng. A. 2010;527:7538–7544. doi: 10.1016/j.msea.2010.08.026. DOI

Speich G.R., Leslie W.C. Tempering of steel. Metall. Trans. 1972;3:1043–1054. doi: 10.1007/BF02642436. DOI

Mola J., Luan G., Brochnow D., Volkova O., Wu J. Tempering of Martensite and Subsequent Redistribution of Cr, Mn, Ni, Mo, and Si Between Cementite and Martensite Studied by Magnetic Measurements. Metall. Mater. Trans. A. 2017;48:5805–5812. doi: 10.1007/s11661-017-4374-5. 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

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

Teramoto S., Imura M., Masuda Y., Ishida T., Ohnuma M., Neishi Y., Suzuki T. Influence of Iron Carbide on Mechanical Properties in High Silicon-added Medium-carbon Martensitic Steels. ISIJ Int. 2020;60:182–189. doi: 10.2355/isijinternational.ISIJINT-2019-331. DOI

Abbasi E., Luo Q., Owens D. Microstructural Characteristics and Mechanical Properties of Low-Alloy, Medium-Carbon Steels After Multiple Tempering. Acta Metall. Sin. English Lett. 2019;32:74–88. doi: 10.1007/s40195-018-0805-6. DOI

Haiko O., Kaijalainen A., Pallaspuro S., Hannula J., Porter D., Liimatainen T., Kömi J. The Effect of Tempering on the Microstructure and Mechanical Properties of a Novel 0.4C Press-Hardening Steel. Appl. Sci. 2019;9:4231. doi: 10.3390/app9204231. 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

Massardier V., Goune M., Fabregue D., Selouane A., Douillard T., Bouaziz O. Evolution of microstructure and strength during the ultra-fast tempering of Fe–Mn–C martensitic steels. J. Mater. Sci. 2014;49:7782–7796. doi: 10.1007/s10853-014-8489-4. 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

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

Zhu K., Shi H., Chen H., Jung C. Effect of Al on martensite tempering: Comparison with Si. J. Mater. Sci. 2018;53:6951–6967. doi: 10.1007/s10853-018-2037-6. DOI

Kim B., Celada C., San Martín D., Sourmail T., Rivera-Díaz-del-Castillo P.E.J. The effect of silicon on the nanoprecipitation of cementite. Acta Mater. 2013;61:6983–6992. doi: 10.1016/j.actamat.2013.08.012. 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

Dlouhy J., Podany P., Džugan J. Influence of Martensite Deformation on Cu Precipitation Strengthening. Metals. 2020;10:282. doi: 10.3390/met10020282. DOI

Takaki S., Fujioka M., Aihara S., Nagataki Y., Yamashita T., Sano N., Adachi Y., Nomura M., Yaguchi H. Effect of copper on tensile properties and grain-refinement of steel and its relation to precipitation behavior. Mater. Trans. 2004;45:2239–2244. doi: 10.2320/matertrans.45.2239. DOI

Gokhman A., Nový Z., Salvetr P., Ryukhtin V., Strunz P., Motyčka P., Zmeko J., Kotous J. Effects of Silicon, Chromium, and Copper on Kinetic Parameters of Precipitation during Tempering of Medium Carbon Steels. Materials. 2021;14:1445. doi: 10.3390/ma14061445. PubMed DOI PMC

Sarikaya M., Jhingan A.K., Thomas G. Retained austenite and tempered martensite embrittlement in medium carbon steels. Metall. Trans. A. 1983;14:1121–1133. doi: 10.1007/BF02659860. DOI

Zia-Ebrahimi F., Krauss G. Mechanisms of tempered martensite embrittlement in medium-carbon steels. Acta Metall. 1984;32:1767–1778. doi: 10.1016/0001-6160(84)90233-5. DOI

Zhao Y., Ren X., Hu Z., Xiong Z., Zeng J., Hou B. Effect of tempering on microstructure and mechanical properties of 3Mn-Si-Ni martensitic steel. Mater. Sci. Eng. A. 2018;711:397–404. doi: 10.1016/j.msea.2017.11.037. DOI

Ardehali Barani A., Ponge D., Raabe D. Refinement of grain boundary carbides in a Si–Cr spring steel by thermomechanical treatment. Mater. Sci. Eng. A. 2006;426:194–201. doi: 10.1016/j.msea.2006.04.002. DOI

ISO 8458-1:2002 . Steel Wire for Mechanical Springs–Part 1: General Requirements. International Organization for Standardization; Geneva, Switzerland: 2002.

Ungár T., Dragomir I., Révész Á., Borbély A. The contrast factors of dislocations in cubic crystals: The dislocation model of strain anisotropy in practice. J. Appl. Crystallogr. 1999;32:992–1002. doi: 10.1107/S0021889899009334. DOI

Shintani T., Murata Y. Evaluation of the dislocation density and dislocation character in cold rolled Type 304 steel determined by profile analysis of X-ray diffraction. Acta Mater. 2011;59:4314–4322. doi: 10.1016/j.actamat.2011.03.055. DOI

Leiva J.A.V., Morales E.V., Villar-Cociña E., Donis C.A., de Bott S.I. 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

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

Pierce D.T., Coughlin D.R., Clarke K.D., De Moor E., Poplawsky J., Williamson D.L., Mazumder B., Speer J.G., Hood A., Clarke A.J. Microstructural evolution during quenching and partitioning of 0.2C-1.5Mn-1.3Si steels with Cr or Ni additions. Acta Mater. 2018;151:454–469. doi: 10.1016/j.actamat.2018.03.007. DOI

Allain S., Aoued S., Quintin-Poulon A., Gouné M., Danoix F., Hell J.-C., Bouzat M., Soler M., Geandier G. In Situ Investigation of the Iron Carbide Precipitation Process in a Fe-C-Mn-Si Q&P Steel. Materials. 2018;11:1087. doi: 10.3390/ma11071087. PubMed DOI PMC

Barani A.A., Ponge D. Materials Science Forum. Volume 539–543. Trans Tech Publications Ltd.; Stafa-Zurich, Switzerland: 2007. Optimized Thermomechanical Treatment for Strong and Ductile Martensitic Steels; pp. 4526–4531.

Nam W.-J., Choi H.-C. Effects of silicon, nickel, and vanadium on impact toughness in spring steels. Mater. Sci. Technol. 1997;13:568–574. doi: 10.1179/mst.1997.13.7.568. DOI

Kim B., Boucard E., Sourmail T., San Martín D., Gey N., Rivera-Díaz-del-Castillo P.E.J. The influence of silicon in tempered martensite: Understanding the microstructure–properties relationship in 0.5–0.6wt.% C steels. Acta Mater. 2014;68:169–178. doi: 10.1016/j.actamat.2014.01.039. DOI

Wang Z., Qi J., Liu Y. Effect of Silicon Content on the Hardenability and Mechanical Properties of Link-Chain Steel. J. Mater. Eng. Perform. 2019;28:1678–1684. doi: 10.1007/s11665-019-03904-8. DOI

Sun C., Fu P., Liu H., Liu H., Du N., Cao Y. The Effect of Lath Martensite Microstructures on the Strength of Medium-Carbon Low-Alloy Steel. Crystals. 2020;10:232. doi: 10.3390/cryst10030232. DOI

Krauss G. Steels: Processing, Structure and Performance. 2nd ed. ASM International; Novelty, OH, USA: 2015.

Galindo-Nava E.I., Rivera-Díaz-del-Castillo P.E.J. A model for the microstructure behaviour and strength evolution in lath martensite. Acta Mater. 2015;98:81–93. doi: 10.1016/j.actamat.2015.07.018. DOI

Forsik S.A.J., Rivera-Diaz-del-Castillo P.E.J. Encyclopedia of Iron, Steel, and Their Alloys. CRC Press; Boca Raton, FL, USA: 2016. Martensitic Steels: Epsilon Carbides in Tempered; pp. 2169–2181.

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

Fatigue Properties of Spring Steels after Advanced Processing

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