Creep is a design consideration in parts made from metals used in high temperature
applications. So what is creep?
When stress is applied to a metal part at its intended operating temperature, it would be a good
thing if it maintains its shape. If it deforms under the applied stress over long periods of time,
then we have encountered what the metallurgists know as creep. Typically this occurs at a
stress below the yield strength determined by standard tensile test performed at the same
temperature.
Seems logical that the amount of creep we see increases with rising temperature under the
same stress or that if we want the same or less creep we need less stress for any given
material.
Our application then needs to have a material that will last its lifetime under the same conditions
of stress and temperature, in other words its creep strength.