Changes in the state of heat-resistant steel induced by repeated hot deformation
- 53 Downloads
This work deals with the problems of structural regeneration by thermal restoration treatment (TRT). These include the lack of a structural sign showing that TRT is possible, a consensus on TRT modes, the data on the necessary relaxation depth of residual stresses, or criteria of structural restoration. Performing a TRT without solving these problems may deteriorate the properties of steel or even accelerate its destruction. With this in view, the purpose of this work is to determine experimentally how the residual stress state changes under thermal and mechanical loads in order to specify the signs of the restoration of structure and structural stability. The object of this research is unused 12Cr1MoV steel that has been aged naturally for 13 years. Using X-ray dosimetry with X-ray spectral analysis, we study the distribution of internal residual stresses of the first kind during the repeated hot deformation. After repeated thermal deformation, the sample under study transforms from a viscoelastic Maxwell material into a Kelvin-Voigt material, which facilitates structural stabilization. A sign of this is the relaxation limit increase, prevention of continuous decay of an α-solid solution of iron and restoration of the lattice parameter.
Keywordsmetals X-ray diffraction deformation unit cell parameter residual stress
Unable to display preview. Download preview PDF.
- 5.D. French, Metallurgical Failures in Fossil Fired Boilers, 2nd ed., p. 528, John Wiley & Sons, New York, USA (1993).Google Scholar
- 6.G. E. Totten, Steel Heat Treatment: Metallurgy and Technologies, 2nd ed., p. 1077, CRC Press, New York, USA (2006).Google Scholar
- 9.K.-E. Thelning, Steel and Its Heat Treatment: Bofors Handbook, 2nd ed., p. 696, Butterworth and Co., London, UK (1984).Google Scholar
- 15.V. N. Karas, Rosenergoatom 8, 26 (2010) [in Russian].Google Scholar
- 20.A. F. Bogachev, Therm. Eng. 48, 588 (2001).Google Scholar
- 24.A. Z. Issagulov, S. V. Kvon, V. Y. Kulikov, and N. B. Aitbayev, Metalurgija 55, 388 (2016).Google Scholar
- 27.V. F. Rezinskikh, B. E. Shkol'nikova, and G. A. Urusova, Therm. Eng. 47, 899 (2000).Google Scholar
- 28.I. Kaur, Y. Mishin, and W. Gust, Fundamentals of Grain and Interphase Boundary Diffusion, 3 rd ed., p. 528, John Wiley & Sons, New York, USA (1995).Google Scholar
- 31.G. Parkus, Neustanovivshiesja Temperaturnye Naprjazhenija [Transient thermal stresses], p. 252, State Publishing House of Physical and Mathematical Literature, Moscow, Russia (1963).Google Scholar
- 32.R. M. Christensen, Theory of Viscoelasticity: An Introduction, 2nd ed., p. 364, Academic press, New York, USA (1982).Google Scholar