Abstract
An experiment has been performed on the collapse of a thick steel cylindrical shell into a continuous cylinder under the action of a sliding detonation wave. The process of the collapse has been recorded via X-ray photography, and it has been found that the time of collapse in one section is equal to 30 μs. The average degree of deformation is 77% and the rate of deformation is 104 s−1. The structure of steel 20 in the transverse section of the cylinder consists of three zones. In the outer zone, the initial ferrite-pearlite structure changes under the effect of compressive shock wave and localized shears. The shock wave leads to the formation of a high-pressure ɛ phase and twins. Upon the subsequent inertial collapse of the shell, substantial shear deformations arise in the surface layer, which are localized in directions located at angles of 60° to the cylindrical surface. The structure of the middle zone changes under the action of severe plastic deformation, which occurs predominantly in the radial direction. The deformation leads to the appearance of an internal pressure and to an increase in the temperature. As a result of the action of three factors (pressure, temperature, and deformation), the temperature of the formation of austenite decreases by several hundred kelvins. In the free ferrite, an α → γ transformation occurs and quenching takes place following a subsequent sharp decrease in pressure (barothermic quenching). The pearlitic regions suffer plastic deformation. The microhardness of the steel with this structure is equal to the microhardness of quenched steel. The structure of the third, i.e., central, zone, changes under the action of a significant increase in temperature caused by the further increase in the degree of deformation. The complete transformation of ferrite into austenite occurs at the center of this zone, which means that the temperature in this zone reaches 850–900°C or greater. The microhardness decreases to values typical of annealed steel.
Similar content being viewed by others
References
E. I. Zababakhin and I. E. Zababakhin, Phenomena of Unlimited Cumulation (Nauka, Moscow, 1988).
A. G. Ivanov, V. A. Ogorodnikov, and E. S. Tyun’kin, “The behavior of shells under impulsive loading. Small perturbations,” J. Appl. Mech. Tech. Phys. 33, 871–874 (1992).
E. A. Kozlov, I. G. Brodova, S. A. Brichikov, D. M. Gorbachev, and T. I. Yablonskikh, “Characteristics of the structure and spall fractures in Armko-Fe shells under different modes of explosive loading,” Deform. Razrush. Mater. 11, 11–18 (2008).
L. V. Al’tshuler, D. M. Tarasov, and M. P. Speranskaya, “Steel deformation under the explosive shock wave action,” Fiz. Met. Metalloved. 13(5), 738–743 (1962).
G. N. Epshtein, Structure of Metals Deformed by Explosion (Metallurgiya, Moscow, 1988) [in Russian].
V. I. Zel’dovich, I. V. Khomskaya, E. F. Gryaznov, K. M. Demchuk, A. N. Martem’yanov, T. M. Sobolenko, and T. S. Teslenko, “Martensitic transformations under the action of high static and dynamic pressures,” Fiz. Met. Metalloved., No. 1, 151–158 (1990).
V. D. Sadovskii, “Transformations upon steel heating. Structural heredity,” in Metal Science and Heat Treatment of Steel. A Handbook (Metallurgiya, Moscow, 1983), Vol. 2, pp. 83–111 [in Russian].
S. S. D’yachenko, Austenite Formation in Iron-Carbon Alloys (Metallurgiya, Moscow, 1982) [in Russian].
V. D. Sadovskii, V. M. Schastlivtsev, T. I. Tabatchikova, and I. L. Yakovleva, Laser Heating and Structure of Steel (Atlas of Microstructures) (Akad. Nauk SSSR, Ural. Otd., Sverdlovsk, 1989) [in Russian].
V. I. Zel’dovich, I. V. Khomskaya, K. M. Demchuk, and A. N. Martem’yanov, “Formation of lens-shaped crystals of austenite upon heating under pressure,” Dokl. Akad. Nauk SSSR 305, 1116–1120 (1989).
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © V.I. Zel’dovich, N.Yu. Frolova, A.E. Kheifets, S.M. Dolgikh, K.V. Gaan, E.V. Shorokhov, 2015, published in Fizika Metallov i Metallovedenie, 2015, Vol. 116, No. 3, pp. 300–308.
Rights and permissions
About this article
Cite this article
Zel’dovich, V.I., Frolova, N.Y., Kheifets, A.E. et al. Deformation- and temperature-related processes that occur upon the collapse of a thick cylindrical shell made of steel 20. Phys. Metals Metallogr. 116, 285–292 (2015). https://doi.org/10.1134/S0031918X15030163
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0031918X15030163