1961 Volume 47 Issue 12 Pages 1697-1704
The series of eleven gamma-prime precipitated heat-resisting alloys of various matrix compositions were studied from the view point of correlation of high-temperature load-carrying ability and structural stability.
The matrix compositions of specimens were different between Ni-base alloys and Fe-base alloys. Air-and vacuum-arc melted and forged 16mm ∅; bars were used for solution annealing, age hardening, short-time tensile, high-temperature creep-rupture tests, X-ray diffraction and -electron metallography.
The identification of precipitated phases were carried out with the specimens aged for 1, 000 hours at 732 and 815°C, respectively.
The changes of matrix-lattice parameters by aging treatments, γ′-matrix lattice mismatch and the growth of γ′ phase particles were also measured in these specimens. As the Co -content in Ni-base alloys was enhanced increased, high-temperature strength properties and γ′- matrix lattice mismatch of these alloys were increased and the growth of γ′ particles was delayed. High-temperature strength properties and lattice mismatch were decreased with -these alloys, as the Fe content in Ni-base alloys was raised.
On the other hand, with Fe-base alloys high-temperature strength, age-hardening properties and lattice parameters of matrix in aged specimens were decreased markedly, as the Co content was increased.
It was found that the deterioration of high-temperature characteristics in Fe-base alloys was principally caused by a precipitation of massive β phase.
