Effect of increasing Al content on creep rupture performance and microstructure stability of IN 617 alloy
Effect of increasing Al content on creep rupture performance and microstructure stability of IN 617 alloy was studied using high-temperature rupture experiments,scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The results show that after increasing the Al content,based on experimental data of over 40000 h,the extrapolated creep rupture strength of the IN 617 alloy exceeds 170 MPa at 700 ℃ and 100000 h,the creep rupture performance is significantly improved,and the creep rupture fracture mechanism of the alloy is still dominated by the accumulation and growth of micropores.The increase of Al content will significantly promote the precipitation of γ'phase in the IN 617 alloy,increase its content,and also promote the precipitation of TCP phases(Topologically close-packed phases)such as µ phase and σ phase in the alloy,thereby improving the hardness and creep rupture performance of the alloy.However,it has not been found that the TCP phases have an adverse effect on the creep rupture strength of the alloy.The longer the aging treatment time,the larger and more continuous the size of grain boundary precipitates,resulting in a decrease in the bonding strength of grain boundaries,while an increase in Al content will increase the intragranular strength.The combined effect of the two will reduce the creep rupture plasticity of the IN 617 alloy.
IN 617 alloyAl contentcreep rupture performancemicrostructure stabilityprecipitate phase
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