Alloying of austenitic steel surface with zirconium using nitrogen compression plasma flow. (May 2015)

• Record Type: Journal Article
• Authors: Sari, A.H.; Astashynski, V.M.; Kostyukevich, E.A.; Uglov, V.V.; Cherenda, N.N.
• Is Part Of: Vacuum. Volume 115(2015)
• Page Start: 39
• Page End: 45
• Publication Date: 2015-05
• Subjects: Compression plasma flow -- Surface alloying -- Austenitic steel -- Zirconium; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2015.01.032
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: In this study, the effect of a nitrogen compression plasma flow on the microstructural and mechanical properties, as well as on the elemental and phase compositions of a Zr/chromium–nickel steel system has been investigated. The Zr/steel system was exposed to a single pulse of the compression plasma flow or to a series of pulses. The samples were characterized by scanning electron microscopy, Auger electron spectroscopy, X-ray diffraction, and energy dispersive X-ray analyses, and subjected to a Vickers microhardness test. The findings showed the formation of a surface modified layer alloyed by Zr with the thickness of up to ∼12 μm. The modified layer contains α- and γ-iron-based solid solutions, the Fe23 Zr6 intermetallic compound, and ZrN and Cr2 N nitrides due to nitrogen diffusion. The microhardness of the modified layer increased by a factor of ∼2. Highlights: Austenitic steel surface layer was alloyed by Zr up to a depth of ∼12 μm. Surface nitriding and Zr alloying occur by nitrogen compression plasma flows. Steel surface contains α- and γ-iron-based solid solutions, Fe23 Zr6, and Cr2 N. A composite thin film containing ZrN exists on the steel surface. The surface microhardness increased by a factor of ∼2.