Using Magnetoelastic Testing for Mechanical Stresses Evaluation in StructuralComponents

摘要

Structural components of NPP are submitted to the influence of different factors such us temperature, corrosivernenvironment and radiation fields. The combined effect of these factors allied to the presence of residual stresses and thernstresses due to the inservice conditions have an extremely important influence on the components life and inservice behavior.rnTo perform structural integrity and life extension programs, it is important to know the real stress state present in therncomponent. In this context, the possibility to determine the stress state acting in a structural component by means of arnnondestructive test method presents an important feature by the fact that it does not introduce any changes into the materialrntested. Amongst the available nondestructive testing method for stress measurements, the magnetoelastic test method presentsrnadvantages such as the possibility to perform measurements at high temperatures. This paper presents a study concerning tornthe use of the magnetoelastic method as a NDT for determining the stress state in ferromagnetic materials. The experimentsrnwere carried out in ASTM A-515 and ASTM A-36 steels, used for pressure vessels manufacturing. The results obtained havernshown a good sensitivity to stress changes. The main restrictions and applications are discussed.