Effects of different solution heat treatments on the hot ductility of superalloys Part 3 - Waspaloy

Artikel i vetenskaplig tidskrift, 2013

The susceptibility to heat affected zone cracking of Waspaloy has been investigated in terms of its hot ductility, measured as the reduction of area (RA). Gleeble testing with on-heating as well as on-cooling test cycles was carried out to illuminate the influence of different 4 h solution heat treatments between 996 and 1080 degrees C. A ductility maximum of between 80 and 90%RA was found at 1050-1100 degrees C for all conditions in the on-heating tests. Although the different heat treatment conditions showed similar macrohardness, the particle size and distribution of the gamma' and M23C6 phases differed, which significantly affected the on-heating ductility in the lower temperature test region. The ductile to brittle transition was initiated at 1100 degrees C in the on-heating testing with indications of grain boundary liquation at the higher test temperatures. Ductility recovery, as measured in the on-cooling tests from 1240 degrees C, was very limited with <30%RA for all conditions and test temperatures except for the 1080 degrees C/4 h treatment, which exhibited 60%RA at 980 degrees C.