One of the influencing parameters on the Flow Accelerated Corrosion rate in carbon steel is its chromium content. The value of the chromium content in low alloy steel varies from 0.0 to 0.30% according the grade and the influence on FAC has been demonstrated by EDF R&D department on the FAC test loop CIROCO for values from O.04 and up. Values over 0.15% have a significant influence on the FAC rate and the knowledge of the exact Cr content in the different components is important information to the operator to be taken into account. The FAC prediction software BRT-CICERO™ uses the Cr values in order to optimize FAC rate calculations.
The problem is that the manufacturer is not obliged to indicate the exact Cr values. He must only guarantee they are lower than the maximum acceptable values (0.25 or 0.30% depending on the brand for example)

In order to measure the precise chrome values in the components, EDF qualified a measurement method based on the XRF technique (X-Ray Fluorescence technique)

The presentation explains how the qualification was performed, the definition of the necessary tolerances, the results and the precautions to be taken during measurements on site.