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Abstract

The paper presents the analysis of temperature fields, phase transformations, strains and stresses in a cuboidal element made from S235 steel, surfaced with multipass GMA (Gas Metal Arc) method. The temperature field is described assuming a dualdistribution heat source model and summing up the temperature fields induced by the padded weld and by the electric arc. Dependence of stresses on strains is assumed on the basis of tensile curves of particular structures, taking into account the influence of temperature. The calculations were carried out on the example of five welds in the middle of the plate made of S235 steel. The simulation results are illustrated in graphs of thermal cycles, volume shares of structural components and stresses at the selected points of cross-section, and the temperature and strain distributions in the whole cross section.

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Authors and Affiliations

J. Winczek
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Abstract

In the present work, a constitutive model of materials undergoing the plastic strain induced phase transformation and damage evolution has been developed. The model is based on the linearized transformation kinetics. Moreover, isotropic damage evolution is considered. The constitutive model has been implemented in the finite element software Abaqus/Explicit by means of the external user subroutine VUMAT. A uniaxial tension test was simulated in Abaqus/Explicit to compare experimental and numerical results. Expansion bellows was also modelled and computed as a real structural element, commonly used at cryogenic conditions.

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Bibliography

[1] A. Valera-Medina, A. Giles, D. Pugh, S. Morris, M. Pohl, and A. Ortwein. Investigation of combustion of emulated biogas in a gas turbine test rig. Journal of Thermal Science, 27:331–340, 2018. doi: 10.1007/s11630-018-1024-1.
[2] K. Tanaka and I. Ushiyama. Thermodynamic performance analysis of gas turbine power plants with intercooler: 1st report, Theory of intercooling and performance of intercooling type gas turbine. Bulletin of JSME, 13(64):1210–1231, 1970. doi: 10.1299/jsme1958.13.1210.
[3] H.M. Kwon, T.S. Kim, J.L. Sohn, and D.W. Kang. Performance improvement of gas turbine combined cycle power plant by dual cooling of the inlet air and turbine coolant using an absorption chiller. Energy, 163:1050–1061, 2018. doi: 10.1016/j.energy.2018.08.191.
[4] A.T. Baheta and S.I.-U.-H. Gilani. The effect of ambient temperature on a gas turbine performance in part load operation. AIP Conference Proceedings, 1440:889–893, 2012. doi: 10.1063/1.4704300.
[5] F.R. Pance Arrieta and E.E. Silva Lora. Influence of ambient temperature on combined-cycle power-plant performance. Applied Energy, 80(3):261–272, 2005. doi: 10.1016/j.apenergy.2004.04.007.
[6] M. Ameri and P. Ahmadi. The study of ambient temperature effects on exergy losses of a heat recovery steam generator. In: Cen, K., Chi, Y., Wang, F. (eds) Challenges of Power Engineering and Environment. Springer, Berlin, Heidelberg, 2007. doi: 10.1007/978-3-540-76694-0_9.
[7] M.A.A. Alfellag: Parametric investigation of a modified gas turbine power plant. Thermal Science and Engineering Progress, 3:141–149, 2017. doi: 10.1016/j.tsep.2017.07.004.
[8] J.H. Horlock and W.A. Woods. Determination of the optimum performance of gas turbines. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 214:243–255, 2000. doi: 10.1243/0954406001522930.
[9] L. Battisti, R. Fedrizzi, and G. Cerri. Novel technology for gas turbine blade effusion cooling. In: Proceedings of the ASME Turbo Expo 2006: Power for Land, Sea, and Air. Volume 3: Heat Transfer, Parts A and B. pages 491–501. Barcelona, Spain. May 8–11, 2006. doi: 10.1115/GT2006-90516.
[10] F.J. Wang and J.S. Chiou. Integration of steam injection and inlet air cooling for a gas turbine generation system. Energy Conversion and Management, 45(1):15–26, 2004. doi: 10.1016/S0196-8904 (03)00125-0.
[11] Z. Wang. 1.23 Energy and air pollution. In I. Dincer (ed.): Comprehensive Energy Systems, pp. 909–949. Elsevier, 2018. doi: 10.1016/B978-0-12-809597-3.00127-9.
[12] Z. Khorshidi, N.H. Florin, M.T. Ho, and D.E. Wiley. Techno-economic evaluation of co-firing biomass gas with natural gas in existing NGCC plants with and without CO$_2$ capture. International Journal of Greenhouse Gas Control, 49:343–363, 2016. doi: 10.1016/j.ijggc.2016.03.007.
[13] K. Mohammadi, M. Saghafifar, and J.G. McGowan. Thermo-economic evaluation of modifications to a gas power plant with an air bottoming combined cycle. Energy Conversion and Management, 172:619–644, 2018. doi: 10.1016/j.enconman.2018.07.038.
[14] S. Mohtaram, J. Lin, W. Chen, and M.A. Nikbakht. Evaluating the effect of ammonia-water dilution pressure and its density on thermodynamic performance of combined cycles by the energy-exergy analysis approach. Mechanika, 23(2):18110, 2017. doi: 10.5755/j01.mech.23.2.18110.
[15] M. Maheshwari and O. Singh. Comparative evaluation of different combined cycle configurations having simple gas turbine, steam turbine and ammonia water turbine. Energy, 168:1217–1236, 2019. doi: 10.1016/j.energy.2018.12.008.
[16] A. Khaliq and S.C. Kaushik. Second-law based thermodynamic analysis of Brayton/Rankine combined power cycle with reheat. Applied Energy, 78(2):179–197, 2004. doi: 10.1016/j.apenergy.2003.08.002.
[17] M. Aliyu, A.B. AlQudaihi, S.A.M. Said, and M.A. Habib. Energy, exergy and parametric analysis of a combined cycle power plant. Thermal Science and Engineering Progress. 15:100450, 2020. doi: 10.1016/j.tsep.2019.100450.
[18] M.N. Khan, T.A. Alkanhal, J. Majdoubi, and I. Tlili. Performance enhancement of regenerative gas turbine: air bottoming combined cycle using bypass valve and heat exchanger—energy and exergy analysis. Journal of Thermal Analysis and Calorimetry. 144:821–834, 2021. doi: 10.1007/s10973-020-09550-w.
[19] F. Rueda Martínez, A. Rueda Martínez, A. Toleda Velazquez, P. Quinto Diez, G. Tolentino Eslava, and J. Abugaber Francis. Evaluation of the gas turbine inlet temperature with relation to the excess air. Energy and Power Engineering, 3(4):517–524, 2011. doi: 10.4236/epe.2011.34063.
[20] A.K. Mohapatra and R. Sanjay. Exergetic evaluation of gas-turbine based combined cycle system with vapor absorption inlet cooling. Applied Thermal Engineering, 136:431–443, 2018. doi: 10.1016/j.applthermaleng.2018.03.023.
[21] A.A. Alsairafi. Effects of ambient conditions on the thermodynamic performance of hybrid nuclear-combined cycle power plant. International Journal of Energy Research, 37(3):211–227, 2013. doi: 10.1002/er.1901.
[22] A.K. Tiwari, M.M. Hasan, and M. Islam. Effect of ambient temperature on the performance of a combined cycle power plant. Transactions of the Canadian Society for Mechanical Engineering, 37(4):1177–1188, 2013. doi: 10.1139/tcsme-2013-0099.
[23] T.K. Ibrahim, M.M. Rahman, and A.N. Abdalla. Gas turbine configuration for improving the performance of combined cycle power plant. Procedia Engineering, 15:4216–4223, 2011. doi: 10.1016/j.proeng.2011.08.791.
[24] M.N. Khan and I. Tlili. New advancement of high performance for a combined cycle power plant: Thermodynamic analysis. Case Studies in Thermal Engineering. 12:166–175, 2018. doi: 10.1016/j.csite.2018.04.001.
[25] S.Y. Ebaid and Q.Z. Al-hamdan. Thermodynamic analysis of different configurations of combined cycle power plants. Mechanical Engineering Research. 5(2):89–113, 2015. doi: 10.5539/mer.v5n2p89.
[26] R. Teflissi and A. Ataei. Effect of temperature and gas flow on the efficiency of an air bottoming cycle. Journal of Renewable and Sustainable Energy, 5(2):021409, 2013. doi: 10.1063/1.4798486.
[27] A.A. Bazmi, G. Zahedi, and H. Hashim. Design of decentralized biopower generation and distribution system for developing countries. Journal of Cleaner Production, 86:209–220, 2015. doi: 10.1016/j.jclepro.2014.08.084.
[28] A.I. Chatzimouratidis and P.A. Pilavachi. Decision support systems for power plants impact on the living standard. Energy Conversion and Management, 64:182–198, 2012. doi: 10.1016/j.enconman.2012.05.006.
[29] T.K. Ibrahim, F. Basrawi, O.I. Awad, A.N. Abdullah, G. Najafi, R. Mamat, and F.Y. Hagos. Thermal performance of gas turbine power plant based on exergy analysis. Applied Thermal Engineering, 115:977–985, 2017. doi: 10.1016/j.applthermaleng.2017.01.032.
[30] M. Ghazikhani, I. Khazaee, and E. Abdekhodaie. Exergy analysis of gas turbine with air bottoming cycle. Energy, 72:599–607, 2014. doi: 10.1016/j.energy.2014.05.085.
[31] M.N. Khan, I. Tlili, and W.A. Khan. thermodynamic optimization of new combined gas/steam power cycles with HRSG and heat exchanger. Arabian Journal for Science and Engineering, 42:4547–4558, 2017. doi: 10.1007/s13369-017-2549-4.
[32] N. Abdelhafidi, İ.H. Yılmaz, and N.E.I. Bachari. An innovative dynamic model for an integrated solar combined cycle power plant under off-design conditions. Energy Conversion and Management, 220:113066, 2020. doi: 10.1016/j.enconman.2020.113066.
[33] T.K. Ibrahim, M.K. Mohammed, O.I. Awad, M.M. Rahman, G. Najafi, F. Basrawi, A.N. Abd Alla, and R. Mamat. The optimum performance of the combined cycle power plant: A comprehensive review. Renewable and Sustainable Energy Reviews, 79:459–474, 2017. doi: 10.1016/j.rser.2017.05.060.
[34] M.N. Khan. Energy and exergy analyses of regenerative gas turbine air-bottoming combined cycle: optimum performance. Arabian Journal for Science and Engineering, 45:5895–5905, 2020. doi: 10.1007/s13369-020-04600-9.
[35] A.M. Alklaibi, M.N. Khan, and W.A. Khan. Thermodynamic analysis of gas turbine with air bottoming cycle. Energy, 107:603–611, 2016. doi: 10.1016/j.energy.2016.04.055.
[36] M. Ghazikhani, M. Passandideh-Fard, and M. Mousavi. Two new high-performance cycles for gas turbine with air bottoming. Energy, 36(1):294–304, 2011. doi: 10.1016/j.energy.2010.10.040.
[37] M.N. Khan and I. Tlili. Innovative thermodynamic parametric investigation of gas and steam bottoming cycles with heat exchanger and heat recovery steam generator: Energy and exergy analysis. Energy Reports, 4:497–506, 2018. doi: 10.1016/j.egyr.2018.07.007.
[38] M.N. Khan and I. Tlili. Performance enhancement of a combined cycle using heat exchanger bypass control: A thermodynamic investigation. Journal of Cleaner Production, 192:443–452, 2018. doi: 10.1016/j.jclepro.2018.04.272.
[39] M. Korobitsyn. Industrial applications of the air bottoming cycle. Energy Conversion and Management, 43(9-12):1311–1322, 2002. doi: 10.1016/S0196-8904(02)00017-1.
[40] T.K. Ibrahim and M.M. Rahman. optimum performance improvements of the combined cycle based on an intercooler–reheated gas turbine. Journal of Energy Resources Technology, 137(6):061601, 2015. doi: 10.1115/1.4030447.
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Authors and Affiliations

Maciej Ryś

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Abstract

Liquid Metal Extraction process using molten Mg was carried out to obtain Nd-Mg alloys from Nd based permanent magnets at 900oC for 24 h. with a magnet to magnesium mass ratio of 1:10. Nd was successfully extracted from magnet into Mg resulting in ~4 wt.% Nd-Mg alloy. Nd was recovered from the obtained Nd-Mg alloys based on the difference in their vapor pressures using vacuum distillation. Vacuum distillation experiments were carried out at 800oC under vacuum of 2.67 Pa at various times for the recovery of high purity Nd. Nd having a purity of more than 99% was recovered at distillation time of 120 min and above. The phase transformations of the Nd-Mg alloy during the process, from Mg12Nd to α-Nd, were confirmed as per the phase diagram at different distillation times. Pure Nd was recovered as a result of two step recycling process; Liquid Metal Extraction followed by Vacuum Distillation.
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Bibliography

[1] J.D. Widmer, R. Martin, M. Kimiabeigi, SM&T. 3, 7-13 (2015).
[2] S . Kruse, K. Raulf, T. Pretz, B. Friedrich, J. Sustain. Metall. 3, 168-178 (2017).
[3] N. Haque, A. Hughes, S. Lim, C. Vernon, Resources. 3 (4), 614- 635 (2014).
[4] D . Schüler, M. Buchert, R. Liu, S. Dittrich, C. Merz, Study on Rare Earths and Their Recycling Final Report for the Greens/European Free Alliance Group in the European Parliament, Germany 2011.
[5] Saleem H. Ali, Resources 3, 123-134 (2014).
[6] T.H. Okabe, Trans. Inst. Min. Metall. 126 (1-2), 22-32 (2016).
[7] K . Halada, J. Mater. Cycles Waste Manag. 20 (2), 49-58 (2009).
[8] T.H. Okabe, O. Takeda, K. Fukuda, Y. Umetsu, Mater. Trans. 44 (4), 798-801 (2003).
[9] Y. Xu, L.S. Chumbley, F.C. Laabs, J. Mater. Res. 15 (11), 2296- 2304 (2000).
[10] H .J. Chae, Y.D. Kim, B.S. Kim, J.G. Kim, T.S. Kim, J. Alloys Compd. 586 (s1), 143-149 (2014).
[11] T. Akahori, Y. Miyamoto, T. Saeki, M. Okamoto, T.H. Okabe, J. Alloys Compd. 703, 337-343 (2017).
[12] S . Delfino, A. Saccone, R. Ferro, Metall. Trans. A. 21A, 2109-2114 (1990).
[13] A.A. Nayeb-Hashemi, J.B. Clark, Phase Diagrams of Binary Manganese Alloys, ASM International, Ohio (1988).
[14] [H. Okamoto, J. Phase Equilib. 12, 249 (1991).
[15] S . Gorssea, C.R. Hutchinsonb, B. Chevaliera, J.F. Nieb, J. Alloys Compd. 392, 253-262 (2005).
[16] I . Barin, Thermochemical Data of Pure Substances, Germany (1989).
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Authors and Affiliations

Mohammad Zarar Rasheed
1 2
ORCID: ORCID
Sun-Woo Nam
2
ORCID: ORCID
Sang-Hoon Lee
2
ORCID: ORCID
Sang-Min Park
2
ORCID: ORCID
Ju-Young Cho
2
ORCID: ORCID
Taek-Soo Kim
1 2
ORCID: ORCID

  1. University of Science and Technology, Industrial Technology, Daejeon, Republic of Korea
  2. Korea Institute for Rare Metals, Korea Institute of Industrial Technology, Incheon, Republic of Korea
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Abstract

The goal of the research was to analyze the acoustic emission signal recorded during heat treatment. On a special stand, samples prepared from 27MnCrB5-2 steel were tested. The steel samples were heated to 950°C and then cooled continuously in the air. Signals from phase changes occurring during cooling were recorded using the system for registering acoustic emission. As a result of the changes, Widmanstätten ferrite and bainite structures were observed under a scanning microscope. The recorded acoustic emission signal was analyzed and assigned to the appropriate phase transformation with the use of artificial neural networks.
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Bibliography

  1.  T.Z. Wozniak, K. Rozniatowski, and Z. Ranachowski, “Acoustic emission in bearing steel during isothermal formation of midrib,” Met. Mater. Int., vol. 17, pp. 365–373, 2011, doi: 10.1007/s12540-011-0611-4.
  2.  L. Kyzioł, K. Panasiuk, G. Hajdukiewicz, and K. Dudzik, “Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials”, Sensors, vol. 21, p. 145, 2021, doi: 10.3390/s21010145.
  3.  A. Adamczak-Bugno, G. Swit, and A. Krampikowska, “Application of the Acoustic Emission Method in the Assessment of the Technical Condition of Steel Structures,” IOP Conf. Ser.: Mater. Sci. Eng., vol. 471, no. 3 p. 032041, 2019, doi: 10.1088/1757-899X/471/3/032041.
  4.  A. Krampikowska, and A. Adamczak-Bugno, “Evaluation of destructive processes in FRC composites using time-frequency analysis of AE signals,” MATEC Web Conf., vol. 262, p. 06006, 2019, doi: 10.1051/matecconf/201926206006.
  5.  G. Świt, A. Krampikowska, T. Pała, S. Lipiec, and I. Dzioba, “Using AE Signals to Investigate the Fracture Process in an Al–Ti Laminate,” Materials, vol. 13, p. 2909, 2020, doi: 10.3390/ma13132909.
  6.  M. Łazarska, T.Z. Woźniak, Z. Ranachowski, P. Ranachowski, and A. Trafarski, “The application of acoustic emission and artificial neural networks in an analysis of kinetics in the phase transformation of tool steel during austempering,” Arch. Metall. Mater., vol. 62, pp. 603‒609, 2017, doi: 10.1515/amm-2017-0089.
  7.  M. Łazarska, T.Z. Woźniak, Z. Ranachowski, A. Trafarski, and G. Domek, “Analysis of acoustic emission signals at austempering of steels using neural networks,” Met. Mater. Int., vol.  23, pp. 426‒433, 2017, doi: 10.1007/s12540-017-6347-z.
  8.  Y. Li et al., “Acoustic emission study of the plastic deformation of quenched and partitioned 35CrMnSiA steel”, Int. J. Miner. Metall. Mater., vol. 21, pp. 1196–1204, 2014, doi: 10.1007/s12613-014-1027-1.
  9.  B.I. Voronenko, “Acoustic emission during phase transformations in alloys,” Met. Sci. Heat Treat., vol. 24, pp. 545‒553, 1982, doi: 10.1007/BF00769364.
  10.  M. Łazarska, T.Z. Woźniak, Z. Ranachowski, A. Trafarski, and S. Marciniak, “The use of acoustic emission and neural network in the study of phase transformation below MS,” Materials, vol. 14, no. 3, p. 551, 2021, doi: 10.3390/ma14030551.
  11.  T.Z. Wozniak, K. Różniatowski, and Z. Ranachowski, “Application of acoustic emission to monitor bainitic and martensitic transformation,” Kovove Mater., vol. 49, pp. 319‒331, 2011, doi: 10.4149/km_2011_5_319.
  12.  A. Pawełek, Z. Ranachowski, A. Piątkowski, S. Kúdela, Z. Jasieński, and S. Kúdela, “Acoustic emission and strain mechanisms during compression at elevated temperature of ß phase Mg-Li-Al composites reinforced with ceramic fibres,” Arch. Metall. Mater., vol. 52, pp. 41‒48. 2007.
  13.  Z. Ranachowski, “Acoustic emission in the diagnosis of civil structures,” Roads Bridges, vol. 2, pp. 151‒173, 2012.
  14.  J. Ranachowski, Problemy współczesnej akustyki, Polska Akademia Nauk, IPPT, Warszawa, 1991.
  15.  R. Botten, X. Wu, D. Hu, and M.H. Loretto, “The significance of acoustic emission during stressing of TiAl-based alloys,” Acta Mater., vol. 49, pp. 1687‒1691, 2001, doi: 10.1016/S1359-6454(01)00091-X.
  16.  A. Lambert, X. Garat, T. Sturel, A. F. Gourgues, and A. Gingell, “Aplication of Acoustic Emission to the Study of Cleavage Fracture Mechanism in a HSLA Steel,” Scripta Mater., vol. 43, pp. 161‒166, 2000, doi: 10.1016/S1359-6462(00)00386-9.
  17.  K. Panasiuk, L. Kyziol, K. Dudzik, and G. Hajdukiewicz, “Application of the Acoustic Emission Method and Kolmogorov-Sinai Metric Entropy in Determining the Yield Point in Aluminium Alloy,” Materials, vol. 13, p. 1386, 2020, doi: 10.3390/ma13061386.
  18.  A. Pawełek, W.S. Ozgowicz, Z. Ranachowski, and S. Kúdela, “Behaviour of acoustic emission in deformation and microcracking processes of Mg alloys matrix composites subjected to compression tests,” Arch. Curr. Res. Int., vol.8, no. 2, pp. 1‒13, 2017, doi: 10.9734/ ACRI/2017/34598.
  19.  R. Karczewski, A. Zagórski, J. Płowiec, and W. Spychalski, “Charakterystyki sygnałów akustycznych podczas obciążania wybranych stali konstrukcyjnych wykorzystywanych do budowy urządzeń ciśnieniowych,” Weld. Tech. Rev., vol. 83, no. 13, 2011, doi: 10.26628/ wtr.v83i13.417.
  20.  I. Baran, “Non-destructive testing of technical equipment using acoustic emission method,” Nondestr. Testing Diagn., vol. 4, pp. 15‒19, 2019, doi: 10.26357/BNiD.2019.017.
  21.  D. Aggelis, E. Kordatos, and T. Matikas, “Acoustic emission for fatigue damage characterization in metal plates”, Mech. Res. Commun., vol. 38, pp. 106–110, 2011, doi: 10.1016/j.mechrescom.2011.01.011.
  22.  K. Jemielniak, “Some aspects of acoustic emission signal pre-processing,” J. Mater. Process. Tech., vol. 109, pp. 242‒247, 2001, doi: 10.1016/S0924-0136(00)00805-0.
  23.  RILEM Technical Committee (Masayasu Ohtsu), “Recommendation of RILEM TC 212-ACD: acoustic emission and related NDE techniques for crack detection and damage evaluation in concrete,” Mater. Struct., vol. 43, pp. 1177–1181, 2010, doi: 10.1617/s11527- 010-9638-0.
  24.  Z. Ranachowski, “The application of a neural network to classify the acoustic emission waveforms emitted by the concrete under thermal stress,” Arch. Acoust., vol. 21, no. 1, pp. 89‒98, 1996.
  25.  H.K.D.H. Bhadeshia, “Phase transformations contributing to the properties of modern steels,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 58, no. 2, pp. 255–256, 2010, doi: 10.2478/v10175-010-0024-4.
  26.  S.M.C. Van Bohemen, An acoustic emission study of martensitic and bainitic transformations in carbon steel, Delft University Press, 2004.
  27.  A. Pawełek, J. Kuśnierz, J. Bogucka, Z. Jasieński, and Z. Ranachowski, “Acoustic emission and the Portevin-Le Châtelier effect in tensile tested Al alloys before and after processing by accumulative roll bonding,” Arch. Metall. Mater., vol.  54, pp. 83‒88, 2009.
  28.  A. Pawełek et al., “Acoustic emission and the Portevin-Le Chatelier effect in tensile tested Al processed by ARB technique,” Arch. Acoust., vol. 32, no. 4, pp. 955‒962, 2007.
  29.  H.N.G. Wadley and C.B. Scruby, “Cooling rate effects on acoustic emission- microstructure relationships in ferritic steels,” J. Mater. Sci., vol. 26, pp. 5777–5792, 1991, doi: 10.1007/BF01130115.
  30.  C.B. Scruby and H.N.G Wadley, “Tempering Effects on Acoustic Emission Microstructural Relationships in Ferritic Steels,” J. Mater. Sci., vol. 28, pp. 2501–2516, 1993, doi: 10.1007/BF01151686.
  31.  V.V. Roshchupkin et al., “The use of acoustic methods to investigate the dynamics of recrystallization and phase transitions in Armco iron and structural steel,” High Temp., vol.  42, pp. 883–887, 2004, doi: 10.1007/s10740-005-0032-5.
  32.  G.R. Speich and A.J. Schwoeble, “Acoustic Emission During Phase Transformałion in Steel”, in Monitoring Structural Integrity by Acoustic Emission STP571. J. C. Spanner and J.W. McElroy, Eds., ASTM International, USA, 1975, pp. 40‒58.
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Authors and Affiliations

Andrzej Trafarski
1
Małgorzata Łazarska
1
Zbigniew Ranachowski
2
ORCID: ORCID

  1. Institute of Materials Engineering, Kazimierz Wielki University in Bydgoszcz, ul. J.K. Chodkiewicza 30, 85-064 Bydgoszcz, Poland
  2. Institute of Fundamental Technological Research, Polish Academy of Sciences, ul. Pawińskiego 5B, 02-106 Warsaw, Poland
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Abstract

The paper presents an approach to differential equation solutions for the stiff problem. The method of using the classic transformer model to study nonlinear steady states and to determine the current pulses appearing when the transformer is turned on is given. Moreover, the stiffness of nonlinear ordinary differential state equations has to be considered. This paper compares Runge–Kutta implicit methods for the solution of this stiff problem.
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Authors and Affiliations

Bernard Baron
1
ORCID: ORCID
Joanna Kolańska-Płuska
1
ORCID: ORCID
Marian Łukaniszyn
1
ORCID: ORCID
Dariusz Spałek
2
ORCID: ORCID
Tomasz Kraszewski
3
ORCID: ORCID

  1. Faculty of Electrical Engineering, Automatic Control and Informatics, Opole University of Technology, Prószkowska 76, 45-758 Opole, Poland
  2. Institute of Electrotechnics and Informatics, Silesian University of Technology, 10 Akademicka St., 44-100 Gliwice, Poland
  3. Research and Development Center GLOKOR Sp. z o.o., Górnych Wałów 27A St., 44-100 Gliwice, Poland
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Abstract

Replacing mathematical models with artificial intelligence tools can play an important role in numerical models. This paper analyses the modeling of the hardening process in terms of temperature, phase transformations in the solid state and stresses in the elastic-plastic range. Currently, the use of artificial intelligence tools is increasing, both to make greater generalizations and to reduce possible errors in the numerical simulation process. It is possible to replace the mathematical model of phase transformations in the solid state with an artificial neural network (ANN). Such a substitution requires an ANN network that converts time series (temperature curves) into shares of phase transformations with a small training error. With an insufficient training level of the network, significant differences in stress values will occur due to the existing couplings. Long-Short-Term Memory (LSTM) networks were chosen for the analysis. The paper compares the differences in stress levels with two coupled models using a macroscopic model based on CCT diagram analysis and using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) and Koistinen-Marburger (KM) equations, against the model memorized by the LSTM network. In addition, two levels of network training accuracy were also compared. Considering the results obtained from the model based on LSTM networks, it can be concluded that it is possible to effectively replace the classical model in modeling the phenomena of the heat treatment process.
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Authors and Affiliations

Joanna Wróbel
1
Adam Kulawik
1
ORCID: ORCID

  1. Department of Computer Science, Czestochowa University of Technology, Dabrowskiego 73, 42-201 Czestochowa, Poland
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Abstract

In-situ observation of the transformation behavior of acicular ferrite in high-strength low-alloy steel using confocal laser scanning microscopy was discussed in terms of nucleation and growth. It is found that acicular ferrite nucleated at dislocations and slip bands in deformed austenite grains introduced by hot deformation in the non-recrystallization austenite region, and then proceeded to grow into an austenite grain boundary. According to an ex-situ EBSD analysis, acicular ferrite had an irregular shape morphology, finer grains with sub-grain boundaries, and higher strain values than those of polygonal ferrite. The fraction of acicular ferrite was affected by the deformation condition and increased with increasing the amount of hot deformation in the non-recrystallization austenite region.
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Authors and Affiliations

Sang-In Lee
1
ORCID: ORCID
Seung-Hyeok Shin
1
ORCID: ORCID
Hyeonwoo Park
2
ORCID: ORCID
Hansoo Kim
2
ORCID: ORCID
Joonho Lee
2
ORCID: ORCID
Byoungchul Hwang
1
ORCID: ORCID

  1. Seoul National University of Science and Technology, Department of Materials Science and Engineering, Seoul, 01811, Republic of Korea
  2. Korea University, Department of Materials Science and Engineering, Seoul, 02841, Republic of Korea

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