Primærspænding

Primærspænding refers to the inherent stress that exists within a material even in the absence of external loads. This internal stress arises from the manufacturing process and the material's history. For example, during the cooling of a casting, different parts of the material cool at different rates, leading to differential contraction and thus inducing residual stresses. Similarly, processes like welding, machining, or heat treatment can introduce primary stresses due to localized heating and cooling cycles or plastic deformation. These stresses can significantly influence a material's behavior under service loads, affecting its strength, fatigue life, and susceptibility to fracture. Understanding and managing primary stresses is crucial in engineering design to ensure the safety and reliability of components. Techniques like stress relieving heat treatments are often employed to reduce or eliminate these internal stresses.