No abstract

TiC-VC reinforced Fe based hardfacing layers were obtained by shielded manual arc welding (SMAW) of which H08A rare electrodes were coated by different amounts of ferrotitanium (FeTi), ferrovanadium (FeV) and graphite. The microstructure of the hardfacing layers was investigated by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA). The thermodynamics and effect of elements on the carbides were also discussed. It was shown that TiC-VC carbides could be formed during arc welding. The composition and amount of flux evidently affect the microstructure and properties of the coatings. Good crack resistance and higher hardness of the harfacing layer could be obtained, while the amounts of graphite, FeTi and FeV were controlled within a range of 8-10%, 15-18% and 8-12% respectively. TiC-VC reinforced Fe based hardfacing layers possess much greater wear resistance and a smaller friction coefficient than 1045 steel substrate.