INFLUENCE OF PARAMETERS OF THE CALIBRATION PROCESS ON BENDING STIFFNESS OF STEEL ROD. PART 2

The creation of strong structural materials allows the production of rod parts such as shafts and axles with a smaller cross section. Strength in this case is maintained, and rigidity decreases, since a thin and long rod has low stability under the action of a longitudinal force and a small bending stiffness due to a transverse load. The small bending stiffness of the rod parts causes significant problems in their processing and assembly, therefore such parts are usually non-technological. Deformation hardening of long-length small-rigid shafts and thin-walled cylinders causes deformations and deflections, for prevention of which one must sacrifice the productivity of the technological process. Flexural rigidity of long parts depends on loading conditions, product geometry and physical and mechanical properties of the material. In real constructions, when the loading conditions and geometric parameters are specified, the rigidity of the products can be changed only by varying the physical-mechanical properties of the material. If a concrete material is specified, only the elastic modulus (E or G) remains to control the rigidity. However, it has been established in a number of studies that the modulus of elasticity does not practically change under ordinary temperature-force conditions. Therefore, at present, the rigidity of the product can only be increased by constructive measures. In the present work, the possibility of increasing the flexural rigidity of cylindrical calibrated bars due to the formation of technological residual stresses is considered.As a result of the experimentalstudies, the effect of the main calibration parameters on the magnitude and nature of the residualstress distribution was established. The obtained curves are used to simulate the flexural rigidity of calibrated bars, depending on the degree of relative reduction and the basic geometric parameters of the working tool (drag). It was established that an increase in the degree of relative reduction and the length of the calibrating zone of the dies has a positive effect on the rigidity of the rod products with an increase in the angle of the working cone of the tool the bending stiffness of the bars is reduced.

1. Sheftel’N.I. Uluchshenie kachestva i sortamenta prokata [Improvement of quality and assortment of rolled products]. Moscow: Metallurgiya, 1973, 343 p. (In Russ.).

2. Belalov Kh.N., Klekovkin A.A., Klekovkina N.A. etc. Stal’naya provoloka [Steel wire]. Magnitogorsk: MGTU, 2011, 689 p. (In Russ.).

3. Zaides S.A. Ostatochnye napryazheniya i kachestvo kalibrovannogo metalla [Residual stresses and quality of calibrated metal]. Irkutsk, IGU, 1992, 200 p. (In Russ.).

4. Zaides S.A. Okhvatyvayushchee poverkhnostnoe plasticheskoe deformirovanie [Covering surface plastic deformation]. Irkutsk: Izdvo IrGTU, 2001, 309 p. (In Russ.).

5. Alfutov N.A. Osnovy rascheta na ustoichivost’ uprugikh system [Basics of calculating the stability of elastic systems]. Moscow: Mashinostroenie, 1978, 312 p. (In Russ.).

6. Silaev B.M. Detali mashin i osnovy konstruirovaniya [Machine parts and design basics]. Samara: Izd-vo SGAU, 2011, 224 p. (In Russ.).

7. Nemets Ya.K. Zhestkost’ i prochnost’ stal’nykh detalei [Stiffness and strength of steel parts]. Moscow: Mashinostroenie, 1970, 528  p. (In Russ.).

8. Resler I., Kharders Kh., Beker M. Mekhanicheskoe povedenie konstruktsionnykh materialov [Mechanical behavior of structural materials]. Dolgoprudnyi: ID Intellekt, 2011, 504 p. (In Russ.).

9. Komarov V.A. Increase of rigidity of structures by topological means. Vestnik samarskogo gosudarstvennogo aerokosmicheskogo universiteta im. akademika S.P. Koroleva. 2003, no. 1, pp. 26–37. (In Russ.).

10. Tekhnologicheskoe obespechenie i povyshenie ekspluatatsionnykh svoistv detalei mashin i ikh soedinenii. Biblioteka tekhnologa [Technological maintenance and increase of operational properties of machine parts and their connections. Technologist’s library]. Moscow: Mashinostroenie, 2006, 448 p. (In Russ.).

11. Boitsov V.B., Chernyavskii A.O. Tekhnologicheskie metody povysheniya prochnosti i dolgovechnosti [Technological methods of increasing strength and durability]. Moscow: Mashinostroenie, 2005, 128 p. (In Russ.).

12. Baryshov S.N. Otsenka povrezhdennosti, nesushchei sposobnosti i prodlenie resursa tekhnologicheskogo oborudovaniya [Assessment of damage, bearing capacity and extension of the resource of process equipment]. Moscow: Nedra-Biznestsentr, 2007, 287  p. (In Russ.).

13. Zaides S.A., Nguen V.Kh. Increasing the rigidity of long shafts by embracing plastic deformation. Uprochnyayushchie tekhnologii i pokrytiya. 2016, no. 2 (134), pp. 10–15. (In Russ.).

14. Uprugost’ i neuprugost’. Materialy mezhdunarodnogo nauchnogo simpoziuma po problemam mekhaniki deformiruemykh tel, posvyashchennogo 100-letiyu so dnya rozhdeniya A.A. Il’yushina, Moskva, 20-21 yanvarya 2011 [Elasticity and Inelasticity. Materials of Int. Sci. Symposium on Mechanical Problems of Deformed Bodies dedicated to 100-Anniversary of A.A. Il’yushin, Moscow, 21-22 of January, 2011]. Kiiko I.A., Brovko G.L., Vasina R.A. eds. Moscow: izd-vo Moskovskogo un-ta, 2011, 483 p. (In Russ.).

15. Gerasimov V.Ya. Determination of uniform hardening of calibrated metal by settling of high cylinders. Izvestiya VUZov. Chernaya metallurgiya = Izvestiya. Ferrous Metallurgy. 1981, no. 6, pp. 54–58. (In Russ.).

16. Gerasimov V.Ya., Kopyrin V.I. Change in the stiffness of the coldrolled steel by its bending. Stal’. 1998, no. 8, pp. 47–48. (In Russ.).

17. Zaides S.A., Nguen V.Kh. Influence of residual stresses on flexural rigidity of long shafts. Vestnik IrGTU. 2015, no. 9 (114), pp. 45–49. (In Russ.).

18. Zaides S.A., Nguen Van Khuan. Influence of parameters of the calibration process on bending stiffness of steel rod. Part 1. Determination of residual stresses in the calibrated rod. Izvestiya VUZov. Chernaya metallurgiya = Izvestiya. Ferrous Metallurgy. 2017, vol.  60, no. 11, pp. 870-876. (In Russ.).

19. Lur’e A.I. Teoriya uprugosti [Theory of elasticity]. Moscow: Nauka, 1970, 256 p. (In Russ.).

20. Pisarenko G.S., Yakovlev A.P., Matveev V.V. Spravochnik po soprotivleniyu materialov [Handbook on the resistance of materials]. Kiev: Naukova dumka, 1988, 736 p. (In Russ.).

21. Basov K.A. ANSYS v primerakh i zadachakh [ANSYS in examples and tasks]. Moscow: Komp’yuter Press, 2002, 224 p. (In Russ.).

22. Bruyaka V.A. Inzhenernyi analiz v ANSYS Workbech [Engineering analysis in ANSYS Workbech]. Samara: Samarskii gos. tekhn. un-t, 2013, 149 p. (In Russ.).