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Highlights: [•] The as-received microstructure of bulk Fe2B comprises iron and silicon borides. [•] The orientation of Fe2B in liquid zinc strongly affects on corrosion resistance. [•] The Fe2B/FeB phase transition process of bulk Fe2B in liquid zinc occurs. [•] Phase transition and spalling dominate corrosion of Fe2B in liquid zinc. [Copyright &y& Elsevier]

In this work, the microstructure, alloying element distribution, and borocarbide mechanical properties of high-boron multi-component alloy with Fe-2.0 wt.%B-0.4 wt.%C-6.0 wt.%Cr-x wt.%Mo-1.0%Al-1.0 wt.%Si-1.0 wt.%V-0.5 wt.%Mn (x = 0.0, 2.0, 4.0, 6.0, 8.0) are investigated. The theoretical calculation results and experiments indicate that the microstructure of high-boron multi-component alloy consists of ferrite, pearlite as a matrix and borocarbide as a hard phase. As a creative consideration, through the use of first-principles calculations, the comprehensive properties of borocarbide with different molybdenum concentrations have been predicted. The calculations of energy, state density, electron density and elastic constant of Fe2B crystal cell reveal that substitution of the molybdenum atom in the Fe2B crystal cell can remarkably improve its thermodynamic stability, bond strength, and covalent trend. For verifying the accuracy of this theoretical calculation, nano-indentation testing is carried out, the results of which indicate that the actual properties of borocarbide present favorable consistency with the theoretical calculations. [ABSTRACT FROM AUTHOR]

The effects of orientation and lamellar spacing on the interface microstructure and corrosion behavior of a directionally solidified (DS) Fe-B alloy in a hot-dip galvanization bath were investigated. The results indicated that the microstructure of the DS Fe-B alloy consisted of oriented α -Fe and Fe 2 B grains. The oriented Fe 2 B with [002] preferred growth orientation displayed low-angle grain boundaries on the Fe 2 B (001) basal plane. The DS Fe-B alloy with Fe 2 B vertical to the corrosion interface possessed the best corrosion resistance to liquid zinc owing to the formation of an interface-pinning multilayer induced by the Fe 2 B orientation. The epitaxially grown columnar ζ-FeZn 13 products were controlled by the geometric constraint of Fe 2 B grain orientation and size, and a mechanism model that explains the interfacial orientation-pinning behavior is discussed in detail. Transmission electron microscopy (TEM) results revealed that the possible orientation relationships of the oriented Fe 2 B and columnar ζ-FeZn 13 products are (001) Fe2B //(−402) ζ-FeZn13 and [002] Fe2B //[110] ζ-FeZn13 . The corrosion damage of the DS Fe-B alloy with Fe 2 B [002] orientation vertical to the corrosion interface in liquid zinc was governed by the competitive mechanisms of Fe 2 B/FeB transformation and microcrack-spallation resistance, which is proposed as being the result of a multiphase synergistic effect in the micro-structures. [ABSTRACT FROM AUTHOR]

• Temperature effect on oxidation resistance of a Fe-Cr-B-Al-C-Mn-Si alloy is studied. • The oxidation resistance is best at 900 °C; it decreases with rising temperature. • The formation mechanism of oxide scale with bilayer/monolayer structure was discussed. • MnCr 2 O 4 oxides promote protective α-Al 2 O 3 oxide formation. • Selective oxidation of Al suppresses outward diffusion of Cr and Mn. The effect of temperature on the oxidation resistance of a novel wear-resistant Fe-10Cr-1.5B-6Al-0.3C-0.8Mn-0.6Si alloy is investigated. The mass growth rate shows that this alloy exhibits superior oxidation resistance at 900 °C. As the oxidation temperature increases from 900 °C to 1100 °C, the structure of the observed oxide scales transforms from a porous bilayer to a flat monolayer, while the oxidation rate increases sharply. The selective oxidation of Al suppresses the outward diffusion of Cr and Mn to form MnCr 2 O 4 oxides in the monolayer oxide scale, thereby decreasing the oxidation resistance at 1100 °C. [ABSTRACT FROM AUTHOR]