Precipitation behavior in V-6W-4Ti, V-4Ti and V-4Cr-4Ti alloys

The cold rolled V-6W-4Ti, V-4Ti and V-4Cr-4Ti alloys were annealed at 900 and 1100 degreesC for recrystallization and solid solution, respectively. Large precipitates were found in the 900 degreesC annealed ones with main difference in the number density among the alloys. Followed the heat treatments, the alloys were annealed again at 400-900 degreesC for 1 h or aged at 600-800 degreesC for durations up to 50 h. Precipitation hardening was found in solid solution treated alloys after the annealing below 900 degreesC and after the aging at 600 degreesC. The precipitates are Ti and C-rich ones, without the enrichment of W in the V-6W-4Ti alloy. Results showed that the growth of the precipitates was controlled by the diffusion of interstitial solutes of C, N and O. V-4Cr-4Ti showed much stronger precipitation hardening than the others due to Cr addition. (C) 2004 Elsevier B.V. All rights reserved.