Approach to on-line assessment of corrosion degradation under stress

The paper discusses the process of corrosion degradation assessment during running a plant, A stressed part (critical part) of a pressure vessel where the measured values of temperature and pressure are known to be time dependent is assessed. Values of chemical concentrations in global volume surrounding the critical part are measured and local chemical concentrations at the critical part are set by a user. Rapid calculation of stress intensity (K-1) values and its utilisation in the ON-LTNE assessment process of corrosion degradation in stressed places in-service by diagnostic system are discussed.