Abstract
The effects of segregation elements and precipitation elements on the hot-ductility of laboratory melted PC Permalloy were investigated by high temperature tensile test. A mechanism of deterioration of the hot-ductility of PC Permalloy has been also discussed.
Decrease in S didn't improve the hot-ductility markedly. Addition of 0.0020.004% B with 23 ppm S was effective on improving the hot-ductility while 0.004% B added alloy with 1618 ppm S showed a ductility trough. Ca added alloy with 18 ppm S showed good hot-ductility and the addition of Mg also improved the hot-ductility.
It was suggested by Auger Electron Spectroscopy that hot-ductility was greatly affected by S segregation at grain boundary. The mechanism of improvement in the hot-ductility of PC Permalloy by the addition of B was thought to be attributed to the effect of site-competition segregation effect of B and S at grain boundary. Improvement of hot-ductility by the addition of Ca and Mg were thought to be related with the formation of sulfides which were stable below solidus temperature of PC Permalloy.
