MICROSTRUCTURES AND OXIDATION RESISTANCE OF Fe3Al WELD OVERLAY

Using the Fe3Al electrode through manual arc surfacing (MAS),Fe3Al coatings havebeen deposited on the stainless steel substrate.The microstructures,hardness andoxidation resistance of the weld overlay have been investigated.The results show thatcrack-free overlays can be obtained when pre-heating of the substrate at 500℃ andpostweld heat treatment at 700℃ were used.Elements of Al,Cr,Ni etc.transferredbetween the substrate and the overlay,but this does not influence the microhardnessof the substrate and the Fe3Al overlay.Oxidation tests show that the Fe3Al overlayshave excellent oxidation resistance in comparison with the stainless steel substrate at800℃ and 900℃.