The paper is focused on investigation of the high-strength AISI 4340 steel at various temperature and deformation conditions. The article is divided into two specific analyses. The first is to examine the dilatation behavior of the steel at eight different cooling rates, namely, 100, 10, 5, 1, 0.5, 0.1, 0.05 and 0.01 °C·s-1. The mapping of the phase transformations due to varying cooling rates from the austenitizing temperature of 850 °C allows the construction of the CCT diagram for a given high-strength steel. These dilatation curves were also compared with the metallography of the selected samples for the proper construction of the CCT diagram. A further analysis of the high temperature deformation of high strength steel AISI 4340 was performed in the range of temperature 900-1200 °C, and the strain rate was in the range from 0.001 to 10 s-1 with maximum value of the true strain 0.9. Changes in the microstructure were observed using light optical microscopy (LOM). The effect of hot deformation temperature on true stress, peak stress and true strain was investigated. The hardness of all deformed samples, depending on the temperature, the deformation rate and the peak stress σp overall together related with hardness, has also been evaluated.

Faculty of Industrial Technologies Alexander Dubcek University of Trenčín 020 01 Puchov Slovakia

Faculty of Military Technology University of Defence in Brno 662 10 Brno Czech Republic

Faculty of Special Technology Alexander Dubcek University of Trencin 911 06 Trencin Slovakia

Zobrazit více v PubMed

De Andrés C.G., Caballero F.G., Capdevila C., Álvarez L.F. Application of dilatometric analysis to the study of solid–solid phase transformations in steels. Mater. Charact. 2002;48:101–111. doi: 10.1016/S1044-5803(02)00259-0. DOI

Heidary O., Mirzaee O., Honarbakhsh Raouf A., Borhani E. Texture development during austempering process of an AISI 4130 steel. Mater. Sci. Eng. A. 2020;793:139751. doi: 10.1016/j.msea.2020.139751. DOI

Park B.J., Choi J.M., Lee K.J. Analysis of phase transformations during continuous cooling by the first derivative of dilatation in low carbon steels. Mater. Charact. 2012;64:8–14. doi: 10.1016/j.matchar.2011.11.014. DOI

Bansal G., Srivastava V., Chowdhury S.G. Role of solute Nb in altering phase transformations during continuous cooling of a low-carbon steel. Mater. Sci. Eng. A. 2019;767:138416. doi: 10.1016/j.msea.2019.138416. DOI

Pashangeh S., Somani M., Banadkouki S.S.G. Microstructural evolution in a high-silicon medium carbon steel following quenching and isothermal holding above and below the Ms temperature. J. Mater. Res. Technol. 2020;9:3438–3446. doi: 10.1016/j.jmrt.2020.01.081. DOI

Chamanfar A., Chentouf S.M., Jahazi M., Lapierre-Boire L.-P. Austenite grain growth and hot deformation behavior in a medium carbon low alloy steel. J. Mater. Res. Technol. 2020;9:12102–12114. doi: 10.1016/j.jmrt.2020.08.114. DOI

Nawrocki J.G., Dupont J.N., Robino C.V., Puskar J.D., Marder A.R. The mechanism of stress-relief cracking in a ferritic alloy steel. Weld. J. 2003:25–35.

Yamashita M., Viswanathan U.K., Yamamoto I., Kobayashi T. Service-induced changes in the microstructure and mechanical properties of a Cr-Mo-Ni-V turbine steel. ISIJ Int. 1997;37:1133–1138. doi: 10.2355/isijinternational.37.1133. DOI

Zhang J., Baker T.N. Effect of equalization time on the austenite grain size of simulated thin slab direct charged (TSDC) vanadium microalloyed steels. ISIJ Int. 2003;43:2015–2022. doi: 10.2355/isijinternational.43.2015. DOI

Zhan Y.Z., Du Y., Zhuang Y.H. Methods for Phase Diagram Determination. Elsevier; Amsterdam, The Netherlands: 2007. Chapter Four—Determination of Phase Diagrams Using Equilibrated Alloys; pp. 108–150.

Lin J., Bailint D., Pietrzyk M. Microstructure Evolution in Metal Forming Processes. Woodhead Publishing Limited; Cambridge, UK: 2012. p. 416.

Reza T., Abbas N., Reza S. Drawing of CCCT diagrams by static deformation and consideration deformation effect on martensite and bainite transformation in NiCrMoV steel. J. Mater. Process. Technol. 2008;196:321–331. doi: 10.1016/j.jmatprotec.2007.05.059. DOI

Tamura I., Sekine H., Tanaka T., Ouchi C. Thermomechanical Processing of High Strength Low Alloy Steels. Butterworth-Heinemann; Oxford, UK: 1998. p. 256.

Back J.G., Surreddi K.B. Microstructure analysis of martensitic low alloy carbon steel samples subjected to deformation dilatometry. Mater. Charact. 2019;157:109926. doi: 10.1016/j.matchar.2019.109926. DOI

García-Mateo C., Caballero F.G., Capdevila C., De Andrés C.G. Estimation of dislocation density in bainitic microstructures using high-resolution dilatometry. Scr. Mater. 2009;61:855–858. doi: 10.1016/j.scriptamat.2009.07.013. DOI

Yang J., Cao B., Wu Y., Gao Z., Hu R. Continuous cooling transformation (CCT) behavior of a high Nb-containing TiAl alloy. Materialia. 2019;5:100169. doi: 10.1016/j.mtla.2018.11.018. DOI

Pickering E.J., Collins J., Stark A., Connor L.D., Kiely A.A., Stone H.J. In situ observations of continuous cooling transformations in low alloy steels. Mater. Charact. 2020;165:110355. doi: 10.1016/j.matchar.2020.110355. DOI

Barényi I., Majerík J., Bezecný J., Krbaťa M., Sedlák J., Jaroš A. Material and technological aspects while processing of selected ultrahigh strength steel. Manuf. Technol. 2019;19:184–189.

Hunkel M., Surm H., Steinbacher M. Handbook of Thermal Analysis and Calorimetry. Elsevier; Amsterdam, The Netherlands: 2018. p. 860.

Berkowski L. The influence of warm plastic deformation on the structure and on the applicable properties of high speed steel. J. Mater. Process. Technol. 1996;60:637–641. doi: 10.1016/0924-0136(96)02398-9. DOI

Krishnan R.S., Srinivasan R., Devanarayanan S., Pamplin B.R. Thermal Expansion of Crystals. Pergamon Press; Oxford, UK: 1979. p. 316.

Stahl-Eisen-Prüfblatt . Aufstellung von Zeit-Temperatur-Umwandlungsschaubildern für Eisenlegierungen. STAHL-EISEN-Prüfblätter des Vereins Deutscher Eisenhüttenleute, Matplus GmbH; Wuppertal, Germany: 1990.

Stahl-Eisen-Prüfblatt . Guidelines for Preparation, Execution and Evaluation of Dilatometric Transformation Test on Iron Alloys. STAHL-EISEN-Prüfblätter des Vereins Deutscher Eisenhüttenleute, Willey; Hoboken, NJ, USA: 1998.

ASTM Committee A01 on Steel, Stainless Steel and Related Alloys . Standard Practice for Quantitative Measurement and Reporting of Hypoeutectoid Carbon and Low-Alloy Steel Phase Transformations. ASTM International; West Conshohocken, PA, USA: 2004.

Krizan D., Spiradek-Hahn K., Pichler A. Relationship between microstructure and mechanical properties in Nb–V microalloyed TRIP steel. Mater. Sci. Technol. 2014;31:661–668. doi: 10.1179/1743284714Y.0000000637. DOI

Spigarelli S., Cabibbo M., Evangelista E., Bidulská J. A study of the hot formability of an Al-Cu-Mg-Zr alloy. J. Mater. Sci. 2003;38:81–88. doi: 10.1023/A:1021161715742. DOI

Ebrahimi R., Najafizadeh A. A new method for evaluation of friction in bulk metal forming. J. Mater. Process. Technol. 2004;152:136–143. doi: 10.1016/j.jmatprotec.2004.03.029. DOI

Zener C., Hollomon J.H. Effect of Strain Rate Upon Plastic Flow of Steel. J. Appl. Phys. 1944;15:22–32. doi: 10.1063/1.1707363. DOI

Wang Y., Li J., Xin Y., Li C., Cheng Y., Chen X., Rashad M., Liu B., Liu Y. Effect of Zener–Hollomon parameter on hot deformation behavior of CoCrFeMnNiC0.5 high entropy alloy. Mater. Sci. Eng. A. 2019;768:138483. doi: 10.1016/j.msea.2019.138483. DOI

Shang X., Cui Z., Fu M.W. A ductile fracture model considering stress state and Zener–Hollomon parameter for hot deformation of metallic materials. Int. J. Mech. Sci. 2018;144:800–812. doi: 10.1016/j.ijmecsci.2018.06.030. DOI

Krbata M., Eckert M., Krizan D., Barenyi I., Mikušová I. Hot Deformation Process Analysis and Modelling of X153CrMoV12 Steel. Metals. 2019;9:1125. doi: 10.3390/met9101125. DOI

Bräutigam–Matus K., Altamirano-Guerrero G., Salinas-Rodríguez A., Valdés A.F., Goodwin F. Experimental Determination of Continuous Cooling Transformation (CCT) Diagrams for Dual-Phase Steels from the Intercritical Temperature Range. Metals. 2018;8:674. doi: 10.3390/met8090674. DOI

Trzaska J., Dobrzański L.A. Modelling of CCT diagrams for engineering and constructional steels. J. Mater. Process. Technol. 2007;192:504–510. doi: 10.1016/j.jmatprotec.2007.04.099. DOI

Zhang X., Wang H., Hickel T., Rogal J., Li Y., Neugebauer J. Mechanism of collective interstitial ordering in Fe–C alloys. Nat. Mater. 2020;19:849–854. doi: 10.1038/s41563-020-0677-9. PubMed DOI

Pan L., Kwok C.T., Lo K.H. Effect of Multiple-Pass Friction Stir Processing on Hardness and Corrosion Resitance of Martensitic Stainless Steel. Coatings. 2019;9:620. doi: 10.3390/coatings9100620. DOI

Krbata M., Majerík J., Barényi I., Eckert M. Experimental determination of continuous cooling transformation diagram for high strength steel OCHN3MFA. IOP Conf. Ser. Mater. Sci. Eng. 2020:776. doi: 10.1088/1757-899X/776/1/012095. DOI

Barenyi I., Krbat’a M., Majerik J. Structure Evolution of 33NiCrMoV15 Steel in Relation to Tempering Temperature; Proceedings of the 30th International DAAAM Symposium “Intelligent Manufacturing & Automation”; Zadar, Croatia. 23–26 October 2019; pp. 800–805.

Boyer H., Gray A.G. Atlas of Isothermal Transformation and Cooling Transformation Diagrams. American Society for Metals; Cleveland, OH, USA: 1977. p. 181.

Samadi Shahreza Z., Dini G., Taherizadeh A. Improving the Microstructure, Mechanical and Magnetic Properties of AISI 4340 Steel Using the Heat Treatment Process. Int. J. ISSI. 2013;10:18–22.

Penha R.N., Vatavuk J., Couto A.A., de Lima Pereira S.A., De Sousa S.A., de C.F. Canale, L. Effect of chemical banding on the local hardenability in AISI 4340 steel bar. Eng. Fail. Anal. 2015;53:59–68. doi: 10.1016/j.engfailanal.2015.03.024. DOI

Nasar A.A. Ph.D. Thesis. University of Sheffield; Sheffield, UK: 2014. Thermomechanical Processing of 34CrNiMo6 Steel for Large Scale Forging; p. 276.

Popescu N., Cojocaru M., Mikhailov V. Experimental studies on bulk tempering of 34CrNiMo6 steel. Surf. Eng. Appl. Electrochem. 2012;48:28–34. doi: 10.3103/S1068375512010139. DOI

Sajadifar S.V., Yapıcı G.G., Ketabchi M., Bemanizadeh B. High Temperature Deformation Behavior of 4340 Steel: Activation Energy Calculation and Modeling of Flow Response. J. Iron Steel Res. Int. 2013;20:133–139. doi: 10.1016/S1006-706X(13)60226-5. DOI

Silva K., Brito P., Santos I., Câmara M., Abrão A. The behaviour of AISI 4340 steel coatings on low carbon steel substrate produced by friction surfacing. Surf. Coatings Technol. 2020;399:126170. doi: 10.1016/j.surfcoat.2020.126170. DOI

Medina S.F., Hernandez C. General expression of the Zener-Hollomon parameter as a function of the chemical composition of low alloy and microalloyed steels. Acta Mater. 1996;44:137–148. doi: 10.1016/1359-6454(95)00151-0. DOI

Barényi I., Krbaťa M., Majerík J., Mikušová I. Effect of deformation parameters on microstructure evolution and properties of 33NiCrMoV15 steel. IOP Conf. Ser. Mater. Sci. Eng. 2020:776. doi: 10.1088/1757-899x/776/1/012001. DOI