Of Tic-vc-mo <sub> 2 </ Sub> C Particles Enhance The Organization And Properties Of Iron-based Hardfacing Layer

In this paper, different deposit layers were obtained by shield manual arc welding (SMAW) in which H08A bare electrodes were coated by fluxes, to which different measures of ferro-titanium (FeTi), ferro-vanadium (FeV), ferro-molybdenum (FeMo), and graphite had been added. The microstructure of the hardfacing layers was investigated by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and electron probe microanalysis (EPMA). The hardness and wear properties were measured by hardness meter and wear tester, respectively. The effect of the amount of FeTi, FeV, FeMo in the fluxes on the microstructure and properties were also studied. The results showed that TiC-VC- M02C carbides could be formed by direct metallurgy reaction among FeTi, FeV, FeMo and graphite during ace welding. Since those carbides were dispersively distributed in the matrix metal, the hardness of the hardfacing metal was more than HRC59. The microstructure and wear properties were affected by the amount of addition of FeTi, FeV, FeMo and graphite evidently. Good crack resistant and higher hardness of the hardfacing layer could be obtained, while the amounts of graphite, FeTi, FeV and FeMo were controlled within a range of 8-10%, 12-15%, 10-12% and 2-3%, respectively. The microstructure of the deposited layer was low carbon martensite with carbides partiles. The wear resistance of the deposited layer which surfaced by the new type of hardfacing electrode is by approximately 2 times the deposited layer surfaced by D317 hardfacing electrode.