Integration and Automation of Residual Stress and Service Stress Modeling for Superalloy Component Design

Abstract

The residual stress distribution generated during manufacturing processes of a jet engine component plays an important role in determining component life. The heat treatment, machining and pre-service spin variables (if used) contribute to the magnitude and location of residual stresses generated prior to service. Such variables have traditionally not been included in design optimization due to the lack of accurate and efficient process modeling design tools. Increased demand for higher speed and higher temperature disks has necessitated advanced multidisciplinary modeling tools in order to deliver high performance, robust and cost favorable solutions. Component process modeling that considers disk stresses through heat treatment, machining, pre-service spin and design operation has been linked and automated to minimize service stress for locations of interest. This paper uses a superalloy 718 disk as an example to illustrate integration and automation of residual stress and service stress modeling that will ultimately impact component life.

Integrated computational materials engineering from a gas turbine engine perspective

“…A 2.8× increase in total life to failure (crack initiation and crack growth) was observed for the pre-spun components compared to the baseline condition. Further details of this experiment are provided in depth by Shen et al Figure 16 Generic example of detailed design process for a critical rotor compressor blisk [10].…”

“…Successful control of the manufacturing process allows for tailoring of the final component residual stress and potential for total life improvement in low-cycle fatigue crack initiation and fatigue crack growth. The work done by Shen et al [10] opens up the possibility of tailoring the forging shape and/or heat treatment cooling rates to achieve an optimized component solution. Such solution may be minimum weight -a full life component design that meets the sub-system goals.…”

Influence of Pre-strain on the Microstructure and Mechanical Properties of GH4169 Superalloy

“…In the production process of turbine discs, residual stresses are inevitably generated, and their distribution and magnitude have a valid influence on the performance of the discs during service [5] . To reduce deformation during the machining of turbine discs and simultaneously enhance their lifespan, major aerospace engine giants such as GE, PW, and Rolls-Royce employ a technique known as high-speed pre-spinning for stress control during the manufacturing of turbine discs [6] . This technique alters the microstructural state, resulting in considerable effects on the properties of the discs.…”

Experiment and Modelling of the Pre-Strain Effect on the Creep Behaviour of P/M Ni-Based Superalloy FGH96

“…Due to the high requirements of reliability and durability of turbine discs, creep properties of P/M superalloy are of great importance to the safety of the component [ 1 , 2 , 3 , 4 ]. Cold pre-deformation is usually used in engineering practice to control residual stress, to improve dimensional stability, and to improve the low cycle fatigue life of aero-engine discs [ 5 , 6 ]. However, pre-deformation also affects the creep properties of Ni-based superalloys at the same time, which might reduce the creep resistance of the disc material [ 7 , 8 , 9 ].…”