Liquid-Phase Boriding of High-Chromium Steel
- PDF / 1,483,538 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 65 Downloads / 191 Views
id-Phase Boriding of High-Chromium Steel Yu. F. Ivanova, *, V. E. Gromovb, **, D. A. Romanovb, ***, O. V. Ivanovac, ****, and A. D. Teresova, ***** a
Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk, 634055 Russia b Siberian State Industrial University, Novokuznetsk, Kemerovo oblast, Kuzbass, 654007 Russia c Tomsk State University of Architecture and Building, Tomsk, 634003 Russia *e-mail: [email protected] **e-mail: [email protected] ***e-mail: [email protected] ****e-mail: [email protected] *****e-mail: [email protected] Received September 30, 2019; revised October 22, 2019; accepted November 15, 2019
Abstract—The structural-phase states and tribological properties of 12Kh18N10T steel subjected to electroexplosive alloying (EPA) with titanium and boron and subsequent electron-beam processing in various modes in terms of the energy density of the electron beam and the duration of the exposure pulse have been analyzed using methods of modern physical materials science. It has been established that EPA of steel with titanium and boron leads to the formation of a surface layer with multiphase submicro-nanocrystalline structure, characterized by the presence of micropores, microcracks, and microcraters. Complex processing, combining EPA and subsequent irradiation with high-intensity pulsed electron beams, leads to the formation of 60-μm-thick multiphase submicro-nanocrystalline surface layer. It is shown that the phase composition of a surface layer of steel is determined by the mass ratio of titanium and boron during electroexplosive alloying. The microhardness of a modified layer is defined by the relative mass fraction of titanium borides in the surface layer and can be more than 18 times higher than the microhardness of steel in its initial state (before electroexplosive alloying). Modes of complex processing have been determined at which the surface layer containing exclusively titanium borides and intermetallic compounds based on titanium and iron is formed. The maximum (approximately 82% by weight) titanium boride content is observed when steel is processed in a regime with the highest mass of boron powder in the sample (mB = 87.5 mg; mTi/mB = 5.202). With a decrease in mass of boron powder, the relative content of borides in the surface layer of steel decreases. It was found that integrated processing of steel is accompanied by a sevenfold increase in microhardness of the surface layer and wear resistance of the steel increases by more than nine times. Keywords: high-chromium stainless steel, boron, titanium, electric explosive alloying, intense pulsed electron beam, structure, properties DOI: 10.3103/S0967091220070062
INTRODUCTION Conversion of nuclear power plants to more enriched fuel and, accordingly, strengthening the requirements for the absorption ability of materials shows a clear need for an increase in the boron concentration in steels, which are often employed in the fabrication of spent-fuel pools due to the high neutron absorbing ability
Data Loading...
