Study on Carbides in Surfacing Layer

Investigation on the carbides in surfacing layer was comprehensively conducted by scanning electron microscope (SEM),X-ray fluorescence spectroscopy and X-ray diffraction,energy dispersive spectrometry(EDS) and wave dispersive spectrometry (WDS).The thermodynamic condition for the formation of carbides in liquid metal was calculated.The content of Ti and C in the welding metal were 1.46% and 0.84% respectively.Most of titanium in surfacing layer existed in the form of carbides which include the carbides formed in liquid solution and the secondary carbides.The originally precipitated carbides were TiC which were quadrilateral like (2~5 μm in lateral length) and distributed evenly.The secondary carbides were complex carbides of Ti,V and Cr,and they appeared as thin strip or fine granule.