Analysis on fillet loose of stainless steel tube by high-frequency induction brazing

1Cr18Ni9Ti stainless steel tube and 1Crl8Ni9Ti stainless steel bends were welded by high-frequency induction brazing, and the loose defects occurs in the fillet of brazed joint after brazing. The macro morphology and microstructure of brazed joint were observed and analyzed to study the microstructure and morphology of lose by optical microscope (OM) and field emission scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The loose defects were analyzed by energy dispersive spectrometer (EDS), then the distribution regular of the defects was studied. The results show that the roots of fillet exist isometric crystal and a few scattered lose, the middle of fillet exist a lot of dendritic crystal and a few loose, the tail of fillet exist a lot of aggregate shape loose and a lot of oxide slag.