Short-range ordering plays a determining role in the low-cycle fatigue life improvement of fcc metals: A conclusive study on low solid-solution hardening Ni-Cr alloys  

作　　者：Y.J.Zhang D.Han X.W.Li 

机构地区：[1]Department of Materials Physics and Chemistry,School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China [2]State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,China [3]Key Laboratory for Anisotropy and Texture of Materials,Ministry of Education,Northeastern University,Shenyang 110819,China

出　　处：《Journal of Materials Science & Technology》2023年第25期157-171,共15页材料科学技术（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.51571058 and 52171108。

摘　　要：The effect of short-range ordering (SRO) on the low-cycle fatigue (LCF) behavior of low solid-solution hardening Ni-Cr alloys with high stacking fault energies (SFEs) was systematically studied under cycling at constant total strain amplitude (Δε t /2) in the range of 0.1%–0.7%. The results show that an inducement of SRO structures can notably improve the fatigue life of the alloy regardless of Δε t /2, and several unique fatigue characteristics have been detected, including the transition of fatigue cracking mode from intergranular cracking to slip band cracking, the non-negligible evolution from non-Masing behavior in pure Ni to Masing behavior in the Ni-40Cr alloy, and the secondary cyclic hardening behavior in the Ni-10Cr and Ni-20Cr alloys. All these experimental phenomena are tightly associated with the transformation in cyclic deformation mechanisms that is induced by SRO based on the “glide plane softening” effect. Furthermore, a comprehensive fatigue life prediction model based on total hysteresis energy has been reasonably proposed, focusing on the analyses of the macroscopic model parameters (namely the fatigue cracking resistance exponent β and the crack propagation resistance parameter W 0 ) and microscopic damage mechanisms. In brief, on the premise that the effects of SFE and friction stress can be nearly ignored, as in the case of the present low solid-solution hardening Ni-Cr alloys with high SFEs, an enhancement of SRO in face-centered cubic metals has been convincingly confirmed to be an effective strategy to improve their LCF performance.

关 键 词：Ni-Cr alloy Short range ordering Low solid-solution hardening Low-cycle fatigue Slip mode Fatigue life prediction model 

分 类 号：TG146.21[一般工业技术—材料科学与工程]