Abstract: In the paper, the 1-NiCrMoTi single-layer and 2-NiCrMoTi/BCr double-layer coatings produced on austenitic stainless steel AISI 321 by non-vacuum electron beam cladding (NVEB) were investigated. The objective of the work was to examine the influence of boron and chromium alloying on the phase composition, microstructure, microhardness, and heat resistance of the formed coatings. X-ray phase analysis, scanning and transmission electron microscopies revealed that the 1-NiCrMoTi single-layer coating exhibits a homogeneous dendritic microstructure based on a γ-solid solution containing dispersed TiC precipitates and (Mo, Cr)-enriched phase. The 2-NiCrMoTi/BCr double-layer coating contained lamellar precipitates of boride (Fe, Cr)2B that formed a strengthened framework. High-resolution transmission electron microscopy (HRTEM) of these coating types demonstrated the formation of a twin substructure within the borides and a sharp interface between the γ-matrix and the boride. The microhardness of the double-layer coating reached 920 HV, which was 4.5 times higher than that of AISI 321 steel. After 100 h of high-temperature testing, the 1-NiCrMoTi coating exhibited the lowest mass gain (0.39 mg/cm2), while the double-layer coating showed a higher mass gain (0.75 mg/cm2). Due to the formation of a dense protective film with high chromium content on a single-layer 1-NiCrMoTi coating, oxidation resistance increased by 3 times compared to austenitic stainless steel.

Cite: Malyutina Y.N. , Ovdina D.S. , Pukhova E.A. , Dudareva A.A. , Batsanov S.A. , Smirnov A.I. , Losinskaya A.A. , Bataev V.A.
Microstructure and oxidation resistance of Ni-Cr-Mo-Ti/B-Cr composite coatings produced by electron beam cladding
Surface and Coatings Technology. 2026. V.538. 133859 . DOI: 10.1016/j.surfcoat.2026.133859 WOS Scopus OpenAlex

Identifiers:

≡ Web of science:	WOS:001856469700001
≡ Scopus:	2-s2.0-105047798679
≡ OpenAlex:	W7165397480

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