Wrinkling is generally induced because of metal instability and considered as an undesirable defect in sheet metal forming processes. Wrinkling leads to severe influence on functional requirements and aesthetic appeal of final component. Thus, the present research is mainly dedicated on the experimental and numerical analysis for wrinkling behavior prediction of Inconel 718 alloy at elevated temperature conditions. Initially, Yoshida buckling tests (YBT) have been conducted to investigate wrinkling tendencies of Inconel 718 alloy from room temperature (RT) to 600°C by an interval of 200°C. Subsequently, Finite Element (FE) analysis of YBT has been performed to analyze post buckling behavior. Critical strain values at onset of wrinkling are determined and strain based wrinkling limit curves (ε-WLCs) are plotted at different temperatures. In-plane principal strains are transferred to effective plastic strain (EPS) versus triaxiality (η) space to differentiate the transformation between safe and wrinkling instability. Finally, complete forming behavior of alloy is represented by means of fracture, forming, and wrinkling limit curves. The gap between forming and wrinkling limit curves at elevated temperature is ∼1.5 times higher than that at room temperature.

起皱通常是由于金属不稳定性引起的，并且被认为是金属板成形过程中不希望有的缺陷。起皱会严重影响最终组件的功能要求和美感。因此，目前的研究主要致力于 Inconel 718 合金在高温条件下的起皱行为预测的实验和数值分析。最初，吉田屈曲试验 (YBT) 已进行以研究 Inconel 718 合金从室温 (RT) 到 600°C 的起皱趋势，间隔为 200°C。随后，对 YBT 进行了有限元 (FE) 分析以分析后屈曲行为。确定起皱开始时的临界应变值，并在不同温度下绘制基于应变的起皱极限曲线 (ε-WLC)。面内主应变被转移到有效塑性应变 (EPS) 与三轴性 (η) 空间，以区分安全和起皱不稳定性之间的转换。最后，合金的完整成形行为通过断裂、成形和起皱极限曲线来表示。高温下的成型和起皱极限曲线之间的差距比室温高约 1.5 倍。