Microstructural Relieving

What you have there is not a clean term. If you want to relieve stresses from a component, you do a stress-relief annealing. The part is heated in a controlled manner, held at temperature, and then slowly cooled. This reduces the internal stresses that are in there after welding or machining. It lowers the risk of the part cracking or warping later on. It's important to heat the part evenly and not cool it too fast, otherwise you'll introduce new stresses.