A CRITICAL REVIEW OF MEASURING TECHNIQUES FOR CORROSION RATES UNDER FLOW CONDITIONS

摘要

The rotated disc, rotated cylinder, rotated cage, jet impingement, pipes and channels are frequently used to study the corrosion performance of materials in flowing media. All these corrosion investigation and test tools are discussed critically with respect to beneficial aspects and inherent shortcomings. Clear distinction is made between corrosion experiments and electrochemical measurements in order to clarify the depth of information and the limits of application of both approaches. This is important specifically for reliable estimation of threshold conditions for the initiation of flow induced localized corrosion (FILC). For all experimental tools the preferential range of flow regime, the known power laws for mass transport relationships with their range of validity, the equations to quantify wall shear stresses and the equations relating diffusion limited current densities (specifically from microelectrodes) to specific data of the flow system are given. The paper aims to help extracting as much information from flow experiments as possible.