High-temperature oxidation behavior of Fe-25Cr-5Al Arc spraying coatings

According to our modeling of oxygen input into particles at arc spraying (AS) a cored wire of Fe-25Cr-5Al type was developed. The oxidation behavior of AS coatings from this wire was studied in air under atmospheric pressure at 700°C. Influence of Si, Ti was studied by means of mass-change measurements, X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is determined that addition of Si and Ti lead to preventing formation of complex carbides like (Fe, Cr)7C3, spinels like (Fe, Cr) 2O3 and nitrides like AlN. Absence of these carbides, spinels and nitrides leads to significantly improving a protective property of surface oxide layer of Al2O3. Heat resistance of developed coatings was compared with austenitic steels like Tempaloy A-1 and TP 310 ASME SA312 and with ferritic steels like T11 and T122 ASME A213 which are widely used as boiler's materials. Copyright 2012 ASM International® All rights reserved