Internal Stresses in Engineering Materials

Summary

In all materials, workpieces, and components, every small volume element is subject to forces exerted by its surroundings onto the surface of the volume element. The stress tensor can be transposed to any reference system using the tensor transformation laws. Residual stress is the stress, which remains in a body that is stationary and at equilibrium with its surroundings. Residual stresses, thus, are mechanical stresses present in a workpiece or a component, which is not subject to external forces, a momentum, or temperature gradient. The formation of residual stresses during primary forming by hot isostatic pressing (HIP) of a two‐phase material is a well‐defined problem that can be understood relatively easily. Heat treatment processes usually lead to residual stress formation during cooling the component to room temperature because of temperature gradients and/or volume changes induced by phase transformations.