Effect of Nb and V in high carbon steel weld metal

Effect of Nb and V in high carbon weld metal was investigated by means of electron probe microanalysis (EPMA),energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM).Nb influenced the distribution and existing state of carbon strongly,and induced obvious depletion of carbon in matrix and precipitation of plenty of NbC.Changing Nb/C ratio in high carbon weld metal,low carbon mar-tensite matrix or even ferrite matrix could come into being.At the same time,carbides of Cr were restrained and Cr dissolved mainly in solid solution.V had similar effect as that of Nb,but the effect was weaker and the carbides were prone to precipitate along the grain boundary.