Correlation of Microstructure, Hardness, and Fracture Toughness of Fe-Based Surface Composites Fabricated by High-Energy Electron Beam Irradiation with Fe-Based Metamorphic Alloy Powders and VC Powders

Abstract

Iron-based surface composites were fabricated with Fe-based metamorphic alloy powders and VC powders by high-energy electron beam irradiation, and the correlation of their microstructure with hardness and fracture toughness was investigated. Mixtures of metamorphic powders and VC powders were deposited on a plain carbon steel substrate, and then the electron beam was irradiated on these powders without flux, to fabricate surface composites. The composite layers 1.3 to 1.8 mm in thickness contained a large amount (up to 47 vol pct) of hard Cr 2 B and V 8 C 7 particles formed in eutectic colony regions and inside colonies, respectively. The hardness of the surface composites was approximately 2 to 4 times greater than that of the substrate because of Cr 2 B and V 8 C 7 particles. According to the microfracture observation of the composite fabricated with mixing 30 wt pct VC powders, microcracks initiated at coarse V 8 C 7 particles ins inside colonies as well as at Cr 2 B particles in colony regions, and were connected with other microcracks in a zigzag shape. Thus, it showed a higher fracture toughness and hardness twice as high as the composite fabricated without mixing VC powders.

Alkaline corrosion resistance of slag‐free self‐shielded titanium‐added metal‐cored welding overlay

“…Much attention has been focused on the chemical composition-microstructure-wear resistance relationships of high chromium iron-based weld overlay [4][5][6]. The different carbon and chromium additions of overlays produced hypoeutectic, eutectic or hypereutectic structures [7]. Among these three structures, the hypereutectic high chromium iron-based overlays generally exhibited the better wear resistance because of the existence of the larger volume fraction of chromium carbides [8,9].…”

Structure of the Steel Surface-Alloyed with Titanium, Vanadium and Carbon in the Process of Powder Welding by a High-Energy Electron Beam

“…It is well-known, that materials possessing an ultrafine structure with homogeneously distributed hard particles are characterized by enhanced tribological and strength properties. In papers [8][9][10][11][12][13][14][15] the structure and properties of steels with coatings fabricated by electron beam cladding of powder mixtures consisting of TiC, WC, Cr3C2, VC, SiC, B4C carbides were investigated. Applying these materials allowed for an increase of microhardness and wear resistance of surface layers of steel workpieces by several times.…”