Spattering Phenomenon for Iron-Nitrogen System during Arc Welding

Abstract

The spattering phenomenon of molten Iron-Nitrogen system under the conditionof arc melting has been observed using a high speed camera.
It was found that the spattering phenomenon was much related to the nitrogen content of molten iron under the arc. The nitrogen content of arc melted iron (260 ppm O) increases with increasing the nitrogen partial pressure up to P_N2=0.004 atm, while above 0.004 atm, the nitrogen content becomes nearly constant around 650 ppm N, and the spattering phenomenon begins to occur from above 0.004 atm nitrogen partial pressures which correspond to the solubility of nitrogen in the molten pure iron above I atm nitrogen partial pressure of non-arc melting.
From the photographic analysis for spattering particles, the internal pressure of a bubble in the molten iron during the arc melting was calculated from the initial velocity of a spattering particle, which was also a function of supersaturation of nitrogen.