Grants and Contributions:

Grant or Award spanning more than one fiscal year (2017-2018 to 2018-2019).

Thermal fatigue is widely recognized as an important damage mechanism in mixing points of hot and coldx000D
fluids. This phenomenon is an important subject in the life-time management of piping components ofx000D
refineries and power plants. In particular, high frequency temperature fluctuations in tee connections as a resultx000D
of mixing the hot and cold fluids may cause material degradation with consequence of cracking and thus affectx000D
the system integrity.x000D
In order to predict failure caused by cyclic thermal loading, a strain base fatigue curve is needed. In particular,x000D
two group of pipeline steels will be targeted, the 300series stainless steel and 2.25 Cr-1Mo steel. For the formerx000D
ones, strain-based fatigue tests will be conducted at different temperatures to extend the application of ASMEx000D
code for fatigue design for higher strain ranges at higher temperature. For the latter, the temperature range ofx000D
the ASME code will be extended to account for the elevated temperature as seen at the mixing tees.x000D
The results of the proposed research will be used to capture the Chaboche viscoelastic material model whichx000D
will be used in the finite element code to predict thermal fatigue failure of pipeline steels at the mixing tees.x000D
This will help minimize the likelihood of fatigue failure, and therefore, improve the structural integrity ofx000D
piping components of refineries and power plants.