The distinct images of intragranular VC were observed on TEM in superalloy GH36 underwent normal heat treatment and prolonged aging.The size of VC particles were meas- ured by means of Moire pattern,and the misfit bet...The distinct images of intragranular VC were observed on TEM in superalloy GH36 underwent normal heat treatment and prolonged aging.The size of VC particles were meas- ured by means of Moire pattern,and the misfit between VC and austenite was also calculated. The M23C6 enveloped in VC shell was also observed in the prolonged-aged specimens.The coherent relation between intragranular M_(23)C_6 twins and austenite as well as its coherent in- terface were also studied.展开更多
Effects of 650℃ aging for 1—1000 h on structure and hydrogen embrittlement susceptibility (HES)of steel Cr21Ni6Mn9N have been investigated.The results show that M_(23)C_6 type carbide precipitates at grain boundarie...Effects of 650℃ aging for 1—1000 h on structure and hydrogen embrittlement susceptibility (HES)of steel Cr21Ni6Mn9N have been investigated.The results show that M_(23)C_6 type carbide precipitates at grain boundaries and Cr-depletive region appears beside them during aging.The precipitates grow and connect each other as the aging time prolongs.Meanwhile, the degree of Cr-depletion aggravates first and then recovers gradually while the aging time is very long,i.e.,1000 h.The HES of the steel increases with increasing aging time but does not reduce with the recovery of Cr content at the Cr-depletive region.That implies that the ex- isting of carbides at grain boundaries might be the main reason which promotes the HES of steel during aging.展开更多
文摘The distinct images of intragranular VC were observed on TEM in superalloy GH36 underwent normal heat treatment and prolonged aging.The size of VC particles were meas- ured by means of Moire pattern,and the misfit between VC and austenite was also calculated. The M23C6 enveloped in VC shell was also observed in the prolonged-aged specimens.The coherent relation between intragranular M_(23)C_6 twins and austenite as well as its coherent in- terface were also studied.
文摘Effects of 650℃ aging for 1—1000 h on structure and hydrogen embrittlement susceptibility (HES)of steel Cr21Ni6Mn9N have been investigated.The results show that M_(23)C_6 type carbide precipitates at grain boundaries and Cr-depletive region appears beside them during aging.The precipitates grow and connect each other as the aging time prolongs.Meanwhile, the degree of Cr-depletion aggravates first and then recovers gradually while the aging time is very long,i.e.,1000 h.The HES of the steel increases with increasing aging time but does not reduce with the recovery of Cr content at the Cr-depletive region.That implies that the ex- isting of carbides at grain boundaries might be the main reason which promotes the HES of steel during aging.
