The optimized stress rupture properties of IN718 are of great interest to the aerospace industry,particularly in the presence of a notch.The deformation mechanisms for the stress rupture properties of IN718 after diff...The optimized stress rupture properties of IN718 are of great interest to the aerospace industry,particularly in the presence of a notch.The deformation mechanisms for the stress rupture properties of IN718 after different heat treatments,using electron back-scattered diffraction(EBSD)as an important tool,were investigated.The notch sensitivity of IN718 was closely associated with the distribution of theδphase.When the area fraction(A(f))of theδphase was less than 0.56%,the sample failed at the notch;while when A(f)≥2.98%,the notch sensitivity disappeared,and failure occurred on the smooth gauge.Heterogeneous deformation with strain concentrated at the grain boundaries was observed for the notch-and smooth-gauge-failed samples through EBSD analysis.Although intergranular cracking was detected in both cases,the failure mechanisms were different.Grain boundary sliding was the dominant failure mechanism for the notch-failed samples,whereas microvoid coalescence was the dominant failure mechanism for the smooth-gauge-failed samples.展开更多
基金financial support from Taiyuan Iron&Steel(Group)Co.,Ltd.(TISCO,Grant No.KA22TAEC035)Baoshan Iron&Steel Co.,Ltd.(Baosteel,Grant No.BGTAECX0).
文摘The optimized stress rupture properties of IN718 are of great interest to the aerospace industry,particularly in the presence of a notch.The deformation mechanisms for the stress rupture properties of IN718 after different heat treatments,using electron back-scattered diffraction(EBSD)as an important tool,were investigated.The notch sensitivity of IN718 was closely associated with the distribution of theδphase.When the area fraction(A(f))of theδphase was less than 0.56%,the sample failed at the notch;while when A(f)≥2.98%,the notch sensitivity disappeared,and failure occurred on the smooth gauge.Heterogeneous deformation with strain concentrated at the grain boundaries was observed for the notch-and smooth-gauge-failed samples through EBSD analysis.Although intergranular cracking was detected in both cases,the failure mechanisms were different.Grain boundary sliding was the dominant failure mechanism for the notch-failed samples,whereas microvoid coalescence was the dominant failure mechanism for the smooth-gauge-failed samples.
