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The effect of erosion angle on erosion behavior of the as-cast Fe-B alloy in flowing liquid zinc was investigated. The results show that the erosion rate of Fe-B alloy decreases linearly with increasing erosion angle. The erosion resistance of Fe-B alloy is better than that of 316L stainless steel, which is attributed to the favorable barrier effect of net-like FeB that resists erosion by flowing liquid zinc. Meanwhile, the ductile matrix can provide support in preventing borides from spalling and borides cause barrier effect on flowing liquid zinc during liquid zinc erosion, which shows a synergistic erosion-corrosion behavior between the matrix and borides. Moreover, an increase in erosion angle can cause a decrease in the removal effect of the flowing liquid zinc scouring component on the erosion compounds. Therefore, the quantity of erosion compounds increases at the erosion interface, weakening the mass transfer process and decreasing the erosion rate of the Fe-B alloy. [ABSTRACT FROM AUTHOR]

The erosion–corrosion properties and interface microstructure of a Fe–B alloy that contains 3.5 wt% B in flowing liquid zinc have been investigated by electron backscattered diffraction, x-ray diffraction, and scanning electron microscopy to clarify the flowing effect of liquid zinc on erosion performance using a rotating-disk technique. The Fe–B alloy erodes at a low and steady rate in flowing liquid zinc. Flowing liquid zinc can accelerate the iron and zinc mass transfer to form Fe–Zn compounds and promote the removal of loose FeZn13. Much residual corrosion-resistant Fe2B and some erosion products coexist at the erosion interface because of the chemical and micromechanical effects that are created by flowing liquid zinc. The failure of the Fe2B corrosion-resistant skeleton in flowing liquid zinc occurs because of the loss of supporting matrix and also the formation and spread of microcracks during erosion. [ABSTRACT FROM PUBLISHER]

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]

Abstract: In order to investigate the effects of boron concentration on the corrosion resistance of Fe–B alloys in molten zinc, Fe–B alloys, with the boron concentrations of 1.5wt.%, 3.5wt.% and 6.0wt.% respectively, were dipped into a pure molten zinc bath at 460°C and kept in different time intervals. The results show that, in comparison with 1Cr18Ni9Ti stainless steel, Fe–B alloy with 3.5wt.%B exhibits excellent corrosion resistance, due to the dense continuous network or parallel Fe2B phase which hinders the Fe/Zn interface reaction in Fe–B alloys. The energy dispersive spectrum (EDS) results indicate that the coarse and compact δ phase with the length about 40μm generates near the matrix of Fe–B alloy and massive ζ phase occurs close to the liquid zinc. The corrosion process includes Fe/Zn reaction and the isolation and fracture of Fe2B. The failure of boride is mainly caused by the microcrack. [Copyright &y& Elsevier]

The interfacial morphologies and erosion-corrosion behavior of directional Fe-3.5 wt.% B steel in flowing liquid Zn-0.30 wt.% Al were investigated. Adding 0.30 wt.% Al to liquid zinc significantly improved the erosion-corrosion resistance of directional Fe-3.5 wt.% B steel, which possesses greater erosion-corrosion resistance when the [002] orientation of Fe 2 B is perpendicular to the erosion-corrosion interface. The erosion-corrosion interface consisted of an inhibition layer, determined by 0.30 wt.% Al, liquid zinc temperature and Fe 2 B orientation. This interface inhibited the diffusion, controlled Fe 2 B failure mode, resisted micromechanical scouring, and suppressed erosion-corrosion. Deterioration of the inhibition layer at the erosion-corrosion interface resulted in severe erosion-corrosion damage. [ABSTRACT FROM AUTHOR]

Abstract: The effects of chromium addition on the corrosion resistance of Fe–3.5B alloy in liquid zinc bath at 520°C have been investigated. The results show that the matrix of as-cast Fe–3.5B alloy transforms into α-(Fe, Cr) solid solution while the eutectic Fe2B changes into M2B-type boride gradually with the increasing chromium addition. The corrosion resistance of Fe–3.5B alloy can be greatly enhanced by 5wt.% chromium addition that still maintains the netlike structure of boride in it. EDX analysis reveals that the Cr element can enrich in the Γ-Fe3Zn10Cr x (x =1.09 to 1.37) phase of the interface to hinder the diffusion of zinc atoms favorably. The Cr addition has no effect on the Vickers hardness of δ and ζ in the corrosion layer basically. Corrosion mechanism of Fe–3.5B alloys with various Cr additions includes the following processes: the superficial dissolution of Cr at the interface, dissolution of the Cr-depleted zones of the matrix corroded by liquid zinc, and the spalling of boride which lost the supporting role of the matrix completely. The corrosion process is mainly controlled by the diffusion of liquid zinc atoms. [Copyright &y& Elsevier]