PSI - Issue 13

Robert Kruzel et al. / Procedia Structural Integrity 13 (2018) 1626–1631 Kruzel and Ulewicz / Structural Integrity Procedia 00 (2018) 000 – 000

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%), for cord G . Cord D contained higher contents of non-metallic inclusions (0.87 % C, 0.021 % Si and 0.015 % S), compared to cord G ( 0.73% C, 0.28 % Si and 0.016 % S). The presence of such a large amount of non-metallic inclusions, especially in the form of oxides, may cause a reduction in material ductility, thereby making technological processes difficult and, in extreme cases, even leading to wires rupturing during the operation of the product.

Table 7. The decrease in the strength of 2 x 0.30 construction steel cords D – G, depending on the number of fatigue cycles applied.

Percentage decrease in the strength/number of cycles

Cord

% /675

% /1350

% / 2700

% /5400

D E F G

0.28 0.22 0.19 0.14

2.35 1.88 1.22 0.51

8.86 4.76 3.81 1.93

12.73 10.21

7.29 5.43

4. Conclusions

From the investigation carried out it can be concluded that the main signs of the fatigue wear of steel cords made of high-carbon steel is a reduction in their strength, cracking of wires and an elongation of the test specimen section. The distribution of fatigue cracks depends on the number of bends and the method of bending the rope section tested. Unidirectional bending on a testing machine causes lesser material fatigue, compared to bidirectional bending. The fatigue of steel cord caused by bidirectional bending results in a decrease in mechanical properties of the steel cord, regardless of the cord construction. The greatest drop in cord strength relative to the number of fatigue cycles occurred in the case of cord of construction 2 x 0.30 and a lower carbon concentration in the steel (0.73 %). By contrast, the least effect on the cord strength was shown by a test performed on the 3+6 construction cord, which confirms that the cord winding method, as well as the number of wires and their diameter have a key effect on the tension of steel cord. Ashby, M. F., Jones, D. R. H., 2005. Engineering Materials: An introduction to microstructures processing and design, Elsevier, Oxford. Bekaert steel cord catalogue, Bekaert S.A., Zwevegem, Belgium, 1982. Berisha, B., Raemy, C., Becker, C., Hora, P., 2015. Multiscale modelling of failure initiation in a ferritic – pearlitic steel. Acta Materialia 100, 11 – 18. Czarski, A., Skowronek, T., Matusiewicz, P., 2015. Stability of a lamellar structure - Effect of the true interlamellar spacing on the durability of a pearlite colony. Archives of Metallurgy and Materials 60(4), 2499 – 2503. Feng, F., 2014. Texture inheritance of cold drawn pearlite steel wires after austenitization. Materials Science Engineering 618(A), 14 – 21. Golis, B., Błażejowski, Z., Pilarczyk, J. W., 1998. Steel wires for tire reinforcement, Publishing house of Faculty of Metallurgy and Materials Science, Czestochowa, Poland. (In Polish). Grygier, D., 2016. Analysis of the causes of damage to the wires of the steel belt of car tires. Interdisciplinary Journal of Engineering Sciences 4(1), 45 – 49. Grygier, D., Rutkowska- Gorczyca, M., Jasiński, M., Dudziński, D., 2016. The structural and strength changes resulting from modification of heat treatment of high carbon steel. Archives of Metallurgy and Materials 61(2B), 971 – 976. Grygier, D., Rutkowska-Gorczyca, M., 2015. Influence of operating conditions of the steel cord on the structure and selected mechanical and technological properties of high carbon steel. International Journal of Engineering Research and Science 2(4), 1 – 6. Grygier, D., Rutkowska-Gorczyca, M., 2016. Influence of operating conditions of the steel cord on the structure and selected mechanical and technological properties of high carbon steel. International Journal of Engineering Research and Science 2, 138 – 142. Krmela, J., 2017. Tire casings and their material characteristics for computational modelling. The Managers of Quality and Production Association Publishing house, Czestochowa, Poland. Kruzel, R., Suliga, M., 2015. The impact of the steel cord construction of its decline of breaking force after fatigue test in bidirectional bending conditions. Metalurgija 54(1), 214 – 216. Kruzel, R., Suliga, M., Sosna, S., 2015. Influence of steel cord technology on its working properties, Hutnik- Wiadomości hutnicze, 82, 68 – 71 (In Polish). Lee, A. B. L., Liu, D. S., Chawla, M., Ulrich, P. C., 1994. Fatigue of cord-rubber composites, Rubber Chemistry and Technology 67(5), 761 – 774. Massoubre, J., 1984. 35 years of the radial ply tire. Journal of Polymer Science, 39, 129 – 149. Noor, A. K., Tanner, J. A., 1985. Tire modelling and contact problems: Advances and trends in the development of computational models for tires. Computers and Structures 20, 517 – 533. Rao, S., Daniel, I. M., Mc Farlane, D., 2013. Fatigue and fracture behavior of a steel cord/rubber composite. Journal of Thermoplastic Composite Materials 14, 2013 – 224. Tashiro, H., Tarui, T., 2003. State of the art for high tensile strength steel cord, Nippon steel technical report, No. 88. Vedeneev, A. V., 2012. New trends in steel cord development. CIS Iron and Steel Review, 24 – 29. VERT, 2007. Virtual education in rubber technology. Reinforcing materials in rubber products, FI- 04 -B-F- PP - 160531, The Goodyear Tire and Rubber Company, US. References