High Polytechnical School at Sevilla University (Sevilla, Spain):

B. Hortigón Fuentes, Dr.

J. M. Gallardo Fuentes, Dr.

S. Muňoz Moreno, Dr.

Konstanz University of Applied Sciences (Konstanz, Germany) and Thurgau Material Sciences WITg Institute (Tägerwilen,
Switzerland):
P. Gümpel, Dr. Eng., Prof., E-mail: p.guempel@witg.ch

J. Strittmatter, Dr. Eng.

Mechanical properties after stretching testings were calculated and experimentally determined via Tempcore method for bar core, bar surface and whole bar cross section. It was displayed on the base of experiments and imitating simulation that deformation in core and surface areas of a bar are equal and therefore influence of structural parameters in the core area is principally decisive for initiating of neck forming in the surface area. The results showed that resistance to destruction of martensite surface layer has rather less eff ect on bar properties in general in comparison with previous investigations. It is concluded that improvement of core structure quality can help to lower brittleness of the whole bar. It was also proved that used techniques provide good concordance between the obtained results and experimental data. Therefore, the additivity rule for structural components can be used successfully for determination of whole bar parameters, taking into account thickness of surface layer that can be measured easily using hardness sensor. It will simplify practically quality control of products.

1. World Steel Association: World Steel in Figures 2017, Peking, China, 2017, https://www.worldsteel.org/media-centre/pressreleases/2017/world-steelin-fgures-2017.html [Zugriff am 10.07.2018].
2. Santos, J.; Abel Henríques, A.: Proc. Eng. 114 (2015), S. 800/807.
3. Perepérez, B.: Diseño y ductilidad en las construcciones de hormigón armado. In: Eduardo Torroja, la vigencia de un legado, 1a ed., SUPUV, Ed. Valencia, 2002, S. 261/69.
4. Khalifa, H.; Megahed, G. M.; Hamouda, R. M. et al.: J. Mat. Proc. Techn. 230 (2016), S. 244/53.
5. American Iron and Steel Institute: Steel Works, Profile 2017, 2017. http://www.steel.org/~/media/Files/AISI/Reports/2017-AISI-Profile-Book.pdf. [Zugriff am: 11.07.2018].
6. Martínez, D. I.; Niño, O.; Niño, E. et al.: Mechanical properties enhancement through thermal treatment and experimental design, Proc. 60^th Ann. IIE Conf. and Exhib., Institute of Industrial Engineers, 2010, Cancun, Mexiko, Vol. 3, S. 1 877/82.
7. Bontcheva, N.; Petzov, G.: Comput. Mat. Sci. 34 (2005), No. 4, S. 377/88.
8. Niño, O.; Martínez, D. I.; Lizcano, C. et al.: Study of the Tempcore process for the production of high resistance reinforcing rods, Materials Science Forum, Vol. 537–538 (2007), S. 533/40.
9. Rehm, G.; Russwurm, D.: C.R.M. Metall. Reports 51 (1977), S. 3/16.
10. Simon, P.; Economopoulos, M.; Nilles, P.: Iron Steel Eng. 61 (1984) Nr. 3, S. 53/57.
11. Economopoulos, M., Respen, Y., Lessel, G. et al.: C.R.M. Metall. Reports, 45 (1975), S. 3/19.
12. Nikolaou, J.; Papadimitriou, G. D.: Int. J. Impact Eng. 31 (2005) Nr. 8, S. 1065/80.
13. Zheng, H.; Abel, A. A.: J. Mat. in Civil Eng. 11 (1999) Nr. 2, S. 158/65.
14. Riva, P., Franchi, A., Tabeni, D.: Welded TEMPCORE reinforcement behaviour for seismic applications. In: Materials and Structures, Vol. 34 (2001), Iss. 4, pp. 240–247.
15. Nikolau, J., Papadimitriou, G. D.: Construction Build. Mat. 18 (2004) Nr. 4, S. 243/54.
16. Dotreppe, J. C.: Materials Struct. 30 (1997) Nr. 7, S. 430/38.
17. Felicetti, R.; Gambarova, P. G.; Meda, A.: Construction Build. Mat. 23 (2009) Nr. 12, S. 3546/55.
18. Purcell, A.: Mathematical modelling of temperature evolution in the hot rolling of steel, McGill University, Kanada, 2000 (Diss.).
19. Lindemann, A.; Schmidt, J.: J. Mat. Proc. Tech. 169 (2005) Nr. 3, S. 466/75.
20. Nobari; A. H.; Serajzadeh, S.: Appl. Thermal Eng. 31 (2011) Nr. 4, S. 487/92.
21. Hollomon, J. H.; Jaff e, J. H.: Trans. Am. Inst. of Min. Met. Petrol. Engin. 162 (1945), S. 223/49.
22. Maynier, P.; Jungman, B.; Dollet, J.: Hardenability Concepts with Application to Steel, The Met. Society of AIME, Warrendale, USA, 1978, S. 518/45.
23. Grange, R. A.; Hribal, C. R.; Porter, L. F.: Met. Trans. A 8 (1977) Nr. 11, S. 1775/85.
24. Sankar, I. B.; Rao, K. M.; Krishna, A. G.: Int. J. Adv. Manuf. Techn. 47 (2010) Nr. 9-12, S. 1159/66.
25. Çetinel, H., Toparli, M., Özsoyeller, L.: Mech. of Mat. 32 (2000) Nr. 6, S. 339/47.
26. Mukherjee, M.; Dutta, C.; Haldar, A.: Mat. Sci. Eng. A 543 (2012), S. 35/43, 2012.
27. Dimatteo, A.; Vannucci, M.; Colla, V.: Steel Res. Intern. 87 (2016) Nr. 3, S. 276/87.
28. Cadoni, E.; Dotta, M.; Forni, D. et al.: Materials Design 49 (2013), S. 657/66.
29. ISO 6507-1:2005 Metallic materials. Vickers hardness test. Part 1: Test method. International Organization for Standardization (Technical Commitee ISO/ TC164/SC3 Hardness Testing), Ginebra, 2005.
30. Hortigón, B.; Gallardo, J. M.; Nieto-García E. J. et al.: Rev. de Metalurgia 53 (2017), e094.
31. Hortigón, B.; Gallardo, J. M.; Nieto-García, E. J. et al.: Análisis de la geometría de la estricción en los aceros corrugados Tempcore. In: Anales de Mecánica de la Fractura, Comunicaciones del XXXV Encuentro del Grupo Español de Fractura, (2018), S. 40/46.
32. ISO 18203:2106. Steel: Determination of the thickness of surfacehardened layers, Int. Organization for Standardization (Technical Committee: ISO/TC17/SC7 Methods of testing (other than mechanical tests and chemical analysis), 2016.
33. ISO 15630-1:2010: Steel for the reinforcement and prestressing of concrete — Test methods — Part 1: Reinforcing bars, wire rod and wire. International Organization for Standardization (Technical Commitee ISO/ TC17/SC16 Steels for the reinforcement and prestressing of concrete), Ginebra, 2010.
34. ISO 6892-1:2016: Metallic materials — Tensile testing — Part 1: Method of test at room temperature. International Organization for Standardization (Technical Committee: ISO/TC164/SC1 Uniaxial testing), Ginebra, 2010.
35. Nadai, A.: Theory of flow and fracture of solids, McGraw Hill, New York, USA, 1950.
36. Considère, M.: Ann. des ponts chaussées 9 (1885), S. 574/775. 37. Hollomon, J. H.: Trans. Am. Inst. Min. Metall. Petroleum Eng. 162 (1945) S. 268/90.
38. Dieter, G. E.: Mechanical Metallurgy, 2. Aufl., McGraw Hill, New York, USA, 1976.
39. Dowling, N. E.: Mechanical Behaviour of Materials: Engineering Methods for Deformation, Fracture and Fatigue, 2. Aufl ., Upper Saddle River, New York, USA, Prentice Hall, 1999.
40. Aparicio, G.; D’Armas, H.; Ciaccia, M.: Rev. Ingeniería UC 14 (2007), S. 57/63.
41. Voigt, W.: Über die Beziehung zwischen den beiden Elasticitätsconstanten isotroper Körper, [in:] Annalen der Physik, 274 (1889), S. 573/87. https://onlinelibrary.wiley.com/doi/abs/10.1002/andp.18892741206 [Zugriff am: 11.07.2018].