Effects of long-term thermal exposure on γ’ particles evolution and impact toughness in the weld joint of Nimonic 263(N263)superalloy were deeply studied at 750℃.Results showed that the precipitates in the weld met...Effects of long-term thermal exposure on γ’ particles evolution and impact toughness in the weld joint of Nimonic 263(N263)superalloy were deeply studied at 750℃.Results showed that the precipitates in the weld metal were mainly composed of fine γ’ particles,bulky MC carbides,and small M23C6 carbides.With the thermal exposure time increasing from o to 3000 h,γ’ particles in the weld metal grew up from 19.7 nm to 90.1 nm at an extremely slow rate.After being exposed for 1000 h,γ’ particles coarsened and some of them transformed into acicular η phase.At the same time,MC carbides decomposed to form η phase and γ’ particles.This dynamic transition ensured the slight reduction in impact toughness of the weld metal after the thermal exposure,which indicated the stable serving performance of N263 weld joint.展开更多
基金The authors gratefully acknowledge the financial support by the National Natural Science Foundation of China(Nos.51675336 and U1660101)the experimental supports by Instrumental Analysis Center of Shanghai Jiao Tong University(SJTU).
文摘Effects of long-term thermal exposure on γ’ particles evolution and impact toughness in the weld joint of Nimonic 263(N263)superalloy were deeply studied at 750℃.Results showed that the precipitates in the weld metal were mainly composed of fine γ’ particles,bulky MC carbides,and small M23C6 carbides.With the thermal exposure time increasing from o to 3000 h,γ’ particles in the weld metal grew up from 19.7 nm to 90.1 nm at an extremely slow rate.After being exposed for 1000 h,γ’ particles coarsened and some of them transformed into acicular η phase.At the same time,MC carbides decomposed to form η phase and γ’ particles.This dynamic transition ensured the slight reduction in impact toughness of the weld metal after the thermal exposure,which indicated the stable serving performance of N263 weld joint.
