INTERPHASE STRESS CORROSION CRACKING OF Ti_3Al＋Nb IN METHANOL
ZHANG Yue;CHU Wuyang;TIAN Tianlei;WANG Yanbin;QIAO Lijie;XIAO Jimei;(University of Science and Technology Beijing)(Manuscript received 5 July;1993:in revised form l September;1993)
Cite this article:
ZHANG Yue;CHU Wuyang;TIAN Tianlei;WANG Yanbin;QIAO Lijie;XIAO Jimei;(University of Science and Technology Beijing)(Manuscript received 5 July;1993:in revised form l September;1993). INTERPHASE STRESS CORROSION CRACKING OF Ti_3Al＋Nb IN METHANOL. Acta Metall Sin, 1994, 30(1): 35-43.
Abstract Stress corrosion cracking(SCC) in the methanol solution containing 0.6MKCI and hydrogen induced cracking(HIC) at room temperature for the titanium aluminide Ti-24Al-llNb were studied.It was found that SCC of the Ti-24Al-llNb alloy in the methanol solution is very sensitive and the normalized threshold stress intensity of SCC for vavious microstructures are Klscc/Kc=0.53-0.69(constant load specimen) and KISCC/Klc-0.61-0.79(WOL constant deflection specimen),respectively.The threshold stress intensity of HIC during dynamic charging at room temperature is close upon that of SCC,but da/dt or fracture time of HIC is one to three orders lower than that of SCC and the fracture surface for HIC is also different to that for SCC.A kind of interphase SCC for the Ti-24Al-llNb alloy in the methanol solution has been found.For the furnace cooled specimens with low KI,SCC initiated and propagated preferentially along the α2/βinterphase boundaries.There are no interphase SCC for the air cooled specimens or for the furnace cooled specimen with high KI.Correspondent:ZHANG Yue,(Department of Materials Physics.University of Science and Techuology Beijing,Beijing 100083)
