High-Temperature Sealed Disc Spring Compression Load-Holding Performance Testing and Material Parameter Calibration

In high-temperature sealed assemblies, disc springs provide sustained preload to suppress leakage. However, at elevated temperatures, material creep and stress relaxation may reduce elastic recovery and accumulate permanent deformation, thereby degrading sealing reliability. Because the material properties of commercially procured disc springs vary with suppliers and production batches, they are difficult to apply directly in the analysis of high-temperature components. This study investigates Inconel-800 disc springs. Sustained compression tests were conducted at 600–900 °C to systematically obtain load–time responses and the temperature dependence of permanent deformation. The results show that, as temperature increases, the rate of force decay accelerates significantly and the residual load decreases markedly. At 800 °C and 900 °C, the permanent deformation approaches the compression limit, indicating that time-dependent material deformation becomes the dominant factor. Based on these results, a finite-element model consistent with the test conditions was established. Material creep parameters were calibrated from component-level compression data by minimizing the discrepancy between simulated and experimental curves. The identified parameters were validated under different temperature conditions and loading cases. The simulation results agree well overall with the experiments, and the errors remain within engineeringly acceptable limits. This study provides baseline data and an engineering method for obtaining material parameters to support material selection and structural optimization of high-temperature sealed disc springs.