Interfacial segregation kinetics of sulfur and magnetic induction influenced by hydrogen flow rate in thin-gauged 3% Si-Fe strip

Effects of flow rate of hydrogen and final reduction on final texture and magnetic induction have been investigated in 3% Si-Fe alloy strips containing 90-ppm sulfur. After final annealing under a flowing hydrogen atmosphere of 10 l/min, the strip showed a magnetic induction value (B₁₀) higher than 1.9 T, whereas only about 1.6 T was obtained at a flow rate of 3 l/min. Within the range of final reduction in thickness of 30%-60%, the final texture and the magnetic induction revealed little dependence on final reduction. Auger electron spectroscopy indicated that the strong dependence of magnetic induction on the flow rate of hydrogen was due to the difference in segregation kinetics of sulfur at the strip surface. The selective growth kinetics also supported a correlation between segregation kinetics of sulfur, texture development, and magnetic induction.