NONEQUILIBRIUM SEGREGATION IN AN Fe-Ni-Ti ALLOY AND A DUCTILE-BRITTLE-DUCTILE TRANSITION

摘要

Brittleness in an Fe-19.8Ni-2.71Ti ternary alloy has been investigated and a theoretical calculation performed based on a regular solution model. The alloy showed a ductile-brittle-ductile transition with aging time. This was due to the grain boundary segregation of titanium and its subsequent desegregation into the matrix, deeply related to a precipitation reaction in the matrix. The calculated results of the nonequilibrium segregation of the elements were semiquantitatively in agreement with the experimental.