Evaluation of anisotropy of mechanical properties of carbon steel flat products

The purpose of the article is to establish experimentally the effect of material inhomogeneity on the characteristics of strength (σ_в, σ_0.2) and plasticity (δ) on example of a rolled steel sheet. Uniaxial tensile testing was carried out on flat samples of hot-rolled sheet made of St3 alloy cut in three directions relative to rolling: along, across and at the angle of 450. The heterogeneity of structure was established by studying the fracture surface of the destroyed samples after tensile testing. A metallographic research and micromechanical testing (measurement of microhardness) of sections parallel to the fracture surface were carried out as well. The uniaxial tensile testing of flat samples resulted in obtaining the values of the characteristics of strength (σ_в, σ_0.2) and plasticity (δ). The analysis of fracture patterns, microstructure and microhardness values of the material allowed to reveal the structural heterogeneity caused by the presence of fibrous ness and a banded ferrite-pearlite structure oriented along the deformation direction. The formation reason of the latter was the presence of oriented non-metallic inclusions - elongated plastic sulfides. The study determined that the material under investigation features the anisotropy of mechanical properties and structural heterogeneity. The values of the ultimate strength (σ_в) and yield strength (σ_0.2) decrease from the longitudinal direction to the transverse direction (relative to the rolling direction) and vice versa (from the transverse to longitudinal direction) in the first case probably due to the influence of non-metallic inclusions (plastic sulfides) and, as a result, the banded ferrite-pearlite structure; in the second case due to the influence of fiber direction. The values of the relative elongation (δ) decrease from the longitudinal direction to the direction at an angle of 450 and then increase to the transverse direction as a result of different hardening of the material during plastic deformation. This is proved by the obtained microhardness values of the investigated sections and the values of the maximum applied loads during the tensile test. The obtained values are obviously the result of the influence of fiber orientation relative to the existing maximum tensile stresses.

1. Cerda FC, Goulas C, Sabirov I, Papaefthymiou S, Monsalve A, Petrov RH. Micro-structure, Texture and Mechanical Properties in a Low Carbon Steel after Ultrafast Heating. Materials Science and Engineering: A. 2016;672:108–120. https://doi.org/10.1016/j.msea.2016.06.056

2. Omale JI, Ohaeri EG, Tiamiyu AA, Eskandari М, Mostafijur KM, Szpunar JA. Microstructure, Texture Evolution and Mechanical Properties of X70 Pipeline Steel after Different Thermomechanical Treatments. Materials Science and Engineering: A. 2017;703:477–485. https://doi.org/10.1016/j.msea.2017.07.086

3. Lobanov ML, Rusakov GM, Pyshmintsev IY, Danilov SV, Pastukhov VI, Urtsev VN, et al. Making Crystallographic Texture in Steel Products with Phase Shift Transformations. In: Aktual'nye problemy fizicheskogo metallovedeniya stalei i splavov: materialy XXIV Ural'skoi shkoly metallovedovtermistov = Current Issues of Steel and Alloy Physical Metallurgy: Proceedings of XXIV Ural School of Metal Physicists-Thermal Engineers. 19–23 Мarсh 2018, Magnitogorsk. Magnitogorsk: Nosov Magnitogorsk State Technical University; 2018, p. 16–18. (In Russ.)

4. Wang Xiaofeng, Guo Mingxing, Zhang Yan, Xing Hui, Li Yong, Luo Jinru, et al. The Dependence of Microstructure, Texture Evolution and Mechanical Properties of Al–Mg– Si–Cu Alloy Sheet on Final Cold Rolling Deformation. Journal of Alloys and Compounds. 2016;657:906–916. https://doi.org/10.1016/j.jallcom.2015.10.070

5. Puzanov MP, Stepanov SI. Mechanical Properties Anisotropy Research of Cold Rolled Transformer Steel. In: Materialy XVIII Mezhdunarodnoi nauchno-tekhnicheskoi Ural'skoi shkoly-seminara metallovedov-molodykh uchenykh = Proceedings of XVIII International Scientific and Technical Ural School-Seminar of Metal PhysicistsYoung Scientists. 21–23 November 2017, Ekaterinburg. Ekaterinburg: Ural Federal University; 2017, p. 562–566. (In Russ.)

6. Volkova EF, Mostyaev IV, Akinina MV. Comparative Analysis of Mechanical Properties Anisotropy and Microstructure of Semi-Finished Products from High-Strength Magnesium Alloys with REE. Trudy VIAM = Proceedings of VIAM. 2018;5:24–32. https://doi.org/10.18577/2307-6046-2018-0-5-24-33

7. Kostikov IE, Kuznetsov EE, Matchenko NM. Experimental Study of Plastic Anisotropy of Sheet-Rolled Aluminum Alloy Materials. Vestnik Moskovskogo gosudarstvennogo oblastnogo universiteta. Seriya: Fizika-matematika = Bulletin of the Moscow Region State University. Series: Physics and Mathematics. 2017;2:64–71. (In Russ.) https://doi.org/10.18384/2310-7251-2017-2-64-71

8. Liu Hai-Tao, Li Hao-Ze, Li Hua-Long, Gao Fei, Liu GuoHuai, Luo Zhong-Han, et al. Effects of Rolling Temperature on Microstructure, Texture, Formability and Magnetic Properties in Strip Casting Fe-6.5 wt% Si Non-Oriented Electrical Steel. Journal of Magnetism and Magnetic Materials. 2015;391:65–74. https://doi.org/10.1016/j.jmmm.2015.04.105

9. Karparvarfard SMH, Shaha SK, Behravesh SB, Jahed H, Williams BW. Microstructure, Texture and Mechanical Behavior Characterization of Hot Forged Cast ZK60 Magnesium Alloy. Journal of Materials Science & Technology. 2017;33(9):907–918. https://doi.org/10.1016/j.jmst.2017.04.004

10. Liu Hai-Tao, Li Hua-Long, Wang Hui, Liu Yi, Gao Fei, An Ling-Zi, et al. Effects of Initial Microstructure and Texture on Microstructure, Texture Evolution and Magnetic Properties of Non-Oriented Electrical Steel. Journal of Magnetism and Magnetic Materials. 2016;406:149–158. https://doi.org/10.1016/j.jmmm.2016.01.018

11. Ren Chunhua, Zhang Xiaochuan, Ji Hongwei, Zhan Nan, Zhixia Qiao. Effect of Banded Morphology and Grain Size on the Tensile Behavior of Acicular Ferrite in HSLA Steel. Materials Science and Engineering: A. 2017;705:394–401. https://doi.org/10.1016/j.msea.2017.08.109

12. Xiaochuan Zhang, Yong Wang, Jia Yang, Zhixia Qiao, Chunhua Ren, Cheng Chen. Deformation Analysis of Ferrite/Pearlite Banded Structure under Uniaxial Tension using Digital Image Correlation. Optics and Lasers in Engineering. 2016;85:24–28. https://doi.org/10.1016/j.optlaseng.2016.04.019

13. Anisovich AG, Andrushevich AA. Microstructures of Ferrous and Non-Ferrous Metals. Minsk: Beloruskaya navuka; 2015, 132 p. (In Russ.)

14. Zaides SA, Fam DF., Ngo KK. New Processes of Surface Plastic Deformation: Monograph. Irkutsk: Irkutsk National Research Technical University; 2019, 352 p. (In Russ.)

15. Zaides SA. The Wrap-Around Deformation Strengthening of Quill Shafts. Uprochnyayushchie tekhnologii i pokrytiya = Strengthening Technologies and Coatings. 2008;2:3–6. (In Russ.)

16. Zaides SA, Fam Dak Fyong. Surface Plastic Deformation by Transverse Burnishing with Flat Plates. Uprochnyayushchie tekhnologii i pokrytiya = Strengthening Technologies and Coatings. 2016;5:6– 12. (In Russ.)

17. Zaides SA, Nguyen Van Hinh. Oscillating Burnishing Parameters Effect on Hardened Surface Roughness. Vestnik Irkutskogo gosudarstvennogo tehnicheskogo universiteta = Proceedings of Irkutsk State Technical University. 2017;21;4:22–29. https://doi.org/10.21285/1814-3520-2017-4-22-29.

18. Il'yushchenko AF, Markova LV, Chekan VA, Fomikhina IV, Koleda VV. Atlas of Industrial Breakdowns of Various Structures. Minsk: Beloruskaya navuka; 2017, 314 p. (In Russ.)

19. Alifanov AV, Andreev VA, Antanovich AA, Aslanyan NS, Belotserkovskii MA, Belyavin KE, et al. Relevant Issues of Strength. Vitebsk: Vitebsk State Technological University; 2018, 423 p. (In Russ.)

20. Anisovich AG, Rumyantseva IN. Practice of Metallographic Research of Materials. Minsk: Beloruskaya navuka; 2013, 221 p. (In Russ.)