High Temperature Materials
Disc springs functioning at high temperatures use a variety of precipitation-hardened materials from the nickel-base alloys group. The high temperature materials are vastly ductile and exhibit very high fatigue strength. The lower tensile strength and adverse elastic limit – tensile strength ratio are important when designing disc springs made of high temperature material. If ignored, a high degree of setting loss is potential. An upper operating temperature limit is not viable to indicate and the overall spring height lessens under load due to creep. The tangible level of creep is a function of temperature, time and stress. For example, a disc spring can be used at higher temperatures if either a lower load is applied or the duration at the higher temperature is minimal. As a result, the values are valuable references for the maximum temperatures at which the disc springs will demonstrate the same performance as at room temperature. The modulus of elasticity is somewhat lower at the upper temperature limit of the material. Therefore, disc springs produced with thermally stable materials can be used at temperatures approximately 150 °C higher than those acknowledged . High temperature materials generally have long lead times from the steel mills and are typically very expensive. Nimonic 90 is better suited for extremely high temperatures than Inconel X 750 (or Inconel 718).
