Rate of Absorption of Nitrogen in Liquid Iron and Iron Alloys

The transfer of nitrogen across Ihe gas/melal interface is controlled by the trans/lOrt in the metal. Alloying elements such as carbon, chromiulIl, and manganese have /Jractically no effect on the mass transfer coe.Dicients, silicon, however, shows de/Joisoning effect on the surface adsorbed oxygen . The ejJects of surface active agenls, such as oxygen or sul/Jhur, are significanl, and the absOljJtion rates are jJrojJortional 10 the nitrogen /Jartial !Iressure when Ihe melal contains 1II0re Ihan nearly 0 .01% oxygen or O.O.5~o sul/Jhu r. Namely it i, reasonable to regard that Ihe transfer of nitrogen is chemically controlled by Ihe rate of nilrogen adsorjlt ion, since oxygen or sul/Jhur seellls to behave as a !loisOIl on the metal sllljllce. The rales of absor/Jtion ill those melts are rejnesenled as follows :