Effects of Angle and Rate of Twist via Pre-Torsional Deformation on Tensile Properties and Hardness of Hot-Rolled, Low-Alloy Steel Rods
DOI:
https://doi.org/10.48048/tis.2022.5770Keywords:
Pre-torsional deformation, Cold forming, Tensile properties, Hardness, Low-alloy steelAbstract
The effects of twist angle and twist rate during the pre-torsional deformation on tensile and hardness properties of hot-rolled SCM415 low-alloy steel were investigated. Hot-rolled SCM415 round tensile specimens were pre-torsioned using a free-end torsion machine to 36, 72, 144 and 288 degrees at 2 different twist rates of 0.1 and 30 rpm. As the angle and the rate of twist increased, yield strength and ultimate tensile strength increased with a tradeoff in a reduction in ductility. The relationship of true stress and true strain within the uniform plastic deformation were well described by a power law. The strength coefficient and strain hardening exponent obtained from the power-law curve fitting decreased with increasing twist angle and higher twist rate, suggesting that higher shear strain and shear strain rate led to a decrease in work hardening capacity. The local hardness after pre-torsional deformation showed a positive gradient from specimens’ centers to their surfaces along the radial direction. Also, the local hardness at the same radial position increased with the increasing angle and rate of twist. The average grain sizes were uniform along the radial direction and were comparable for all pre-torsional conditions. The strengthening mechanism via pre-torsional deformation of hot-rolled SCM415 was shown to be dominated by the strain hardening effect.
HIGHLIGHTS
- The effects of twist angle and twist rate during the pre-torsional deformation using a free-end torsion tester on tensile and hardness properties of hot-rolled SCM415 low-alloy steel were investigated
- Within uniform plastic deformation region, the power-law parameters, namely strength coefficient (K) and strain hardening exponent (n) decreased with increasing amount of shear plastic strain and shear strain rate during the pre-torsional deformation
- Local Vicker hardness showed a positive gradient from the central region to the surface of pre-torsioned specimens, and the local hardness at the same distance from the center increased with increasing torsional angle and twist rate
- The average grain sizes of pre-torsioned specimens were found to be unaffected by the amount of torsional angle or the rate of twist
- The strengthening of hot-rolled SCM415 steel via pre-torsional deformation is predominated by strain hardening effect
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[ ] LV Long, DV Hien, NT Thanh, NC Tho and VT Do. Impact of cold-rolling and heat treatment on mechanical properties of dual-phase treated low carbon steel. Adv. Mater. Sci. Eng. 2020; 2020, 1674837.
[ ] TY Wang, RB Song, HJ Cai, J Wen and Y Su. Influence of cold rolling reduction on microstructure and mechanical properties in 204C2 austenitic stainless steel. Mater. Sci. Forum 2019; 944, 193-8.
[ ] AC Umamaheshwer Rao, V Vasu, M Govindaraju and KV Sai Srinadh. Influence of cold rolling and annealing on the tensile properties of aluminum 7075 alloy. Procedia Mater. Sci. 2014; 5, 86-95.
[ ] NA Raji and OO Oluwole. Influence of degree of cold-drawing on the mechanical properties of low carbon steel. Mat. Sci. App. 2011; 2, 1556-63.
[ ] MC Nebbar, M Zidani, T Djimaoui, T Abid, H Farh, T Ziar, AL Helbert, F Brisset and T Baudin. Microstructural evolutions and mechanical properties of drawn medium carbon steel wire. Int. J. Eng. Res. Afr. 2019; 41, 1-7.
[ ] SH Huang, Y Wu, XS Xia, ZD Zhao, Q Chen and DY Shu. Assessment of cold extrusion effect on stress-strain curves of pure copper arc parts based on the cosine velocity model. Strength Mater. 2019; 51, 569-77.
[ ] SJ Liang, ZY Liu and ED Wang. Microstructure and mechanical properties of Mg-Al-Zn alloy deformed by cold extrusion. Mater. Lett. 2008; 62, 3051-4.
[ ] L Wang, W Lu, J Qin, F Zhang and D Zhang. Microstructure and mechanical properties of cold-rolled TiNbTaZr biomedical β titanium alloy. Mater. Sci. Eng. A 2008; 490, 421-6.
[ ] X Zhang, A Godfrey, X Huang, N Hansen and Q. Liu. Microstructure and strengthening mechanisms in cold-drawn pearlitic steel wire. Acta Mater. 2011; 59, 3422-30.
[ ] WDJR Callister. and DG Rethwisch. Materials science and engineering: An introduction. 10th eds. Wiley, New Jersey, 2018.
[ ] C Wang, F Li, J Li, J Dong and F Xue. Microstructure evolution, hardening and thermal behavior of commercially pure copper subjected to torsion deformation. Mater. Sci. Eng. A 2014; 598, 7-14.
[ ] C Wang, F Li, L Wang, H Qiao. Review on modified and novel techniques of severe plastic deformation. Sci. China Technol. Sci. 2012; 55, 2377-90.
[ ] RZ Valiev, RK Islamgaliev and IV Alexandrov. Bulk nanostructured materials from severe plastic deformation. Prog. Mater. Sci. 2000; 45, 103-189.
[ ] T Ungár, LS Tóth, J Illy and I Kovács. Dislocation structure and work hardening in polycrystalline ofhc copper rods deformed by torsion and tension. Acta Metall. 1986; 34, 1257-67.
[ ] J Gu, L Zhang, S Ni and M Song. Effects of grain size on the microstructures and mechanical properties of 304 austenitic steel processed by torsional deformation. Micron 2018; 105, 93-7.
[ ] H Chen, F Li, J Li, Z Zhao, S Zhou and Q Wan. Experimental study on pure titanium during the positive-torsion and positive-negative-torsion. Mater. Sci. Eng. A 2016; 674, 552-68.
[ ] JH Hollomon. Tensile deformation. Trans. Am. Inst. Mech. Eng. 1945; 162, 268-77.
[ ] M Bruneau, CM Uang and R Sabelli. Ductile design of steel structures. 2nd eds. McGraw-Hill, New York, 2011.
[ ] WF Hosford and RM Caddell. Metal Forming: Mechanics and metallurgy. 4th eds. Cambridge University Press, New Jersey, 2011.
[ ] JA Schey. Introduction to manufacturing processes. 3rd eds. McGraw-Hill, New York, 2000.
[ ] J Gu, S Ni and M Song. Mechanical properties and microstructural evolution of CuZn alloys via pre-torsional deformation. Mat. Res. 2019; 22, e20180424.
[ ] R Pippan, F Wetscher, M Hafok, A Vorhauer and I Sabirov. The limits of refinement by severe plastic deformation. Adv. Eng. Mater. 2006; 8, 1046-56.
[ ] W Blum and XH Zeng. A simple dislocation model of deformation resistance of ultrafine-grained materials explaining Hall-Petch strengthening and enhanced strain rate sensitivity. Acta Mater. 2009; 57, 1966-74.
[ ] Z Zhang, Q Dong, B Song, H He, L Chai, N Guo, B Wang and Z Yao. Effect of shear strain rate on microstructure and properties of austenitic steel processed by cyclic forward/reverse torsion. Materials 2019; 12, 506.
[ ] RC Souza, ES Silva, AMJR Jorge, JM Cabrera and O Balancin. Dynamic recovery and dynamic recrystallization competition on a Nb- and N-bearing austenitic stainless steel biomaterial: Influence of strain rate and temperature. Mater. Sci. Eng. A 2013; 582, 96-107.
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