The Microstructure of Annealed Galfan Coating on Steel Substrate

Abstract

The Microstructure of AnnealedGalfanCoating on Steel SubstrateThe commercially availableGalfancoating containing 5-7wt.% of Al deposited on the low carbon steel substrate by hot dipping has been examined with respect to the microstructure of the coating/substrate interface area. The application of several experimental techniques (SEM/EDS, XRD, TEM/AEM/EDS/ED) allowed demonstrating the two-phase structure of the alloy coating in non-treated, commercially availableGalfansamples: Zn-rich pre-eutectoidηphase grains are surrounded by lamellar eutectics ofβ-Al andη-Zn. The transition layer between the alloy coating and steel substrate with the considerably higher Al content (SEM/EDS, TEM/EDS) has been found in both non-treated and annealed samples (600°C/5 minutes). Only the monoclinic FeAl3Znxphase however was revealed in the annealed sample (TEM/electron diffraction) remaining uncertain the presence of the orthorhombic Fe2Al5Znxphase, reported by several authors.

The effect of ultrasonic irradiation on the microstructure and corrosion rate of a Zn–4.8wt.% Al galvanising alloy used in high performance construction coatings

“…The presence of Fe was a result of the alloy spelter being taken from the process galvanising bath that is saturated with Fe due to the constant movement of steel strip through it. The XRD data for the sample with no ultrasound provided in figure 7 showed a crystalline structure and peak identification through comparison to previous research on this alloy enabled the identification of  Zn and  Al phases as the predominant structures in the sample [27]. The EDX and XRD data presented support previous research into similar alloys [26,27,28] that the microstructure was composed of primary Zn rich  dendrites surrounded by a eutectic of  Zn /  Al as described in section 3.…”

Structure of Iron-Based Cladding Layer on Al-Mg-Si Alloy Coated by a Resistance Seam Welding Method

“…According to these SAD patterns, it could be concluded that the needle-like Fe-Al phase in BFI images was FeAl 3 . 30,31) The result is in accordance with the result of EPMA line analysis. Moreover, the characteristic feature of twinning with refection plane (001) along [010] axe could also be observed in Fig.…”