Flow‐dependent corrosion. I. Current understanding of the mechanisms involved

Abstract

Wall geometry, flow and corrosion patterns are interrelated and lead to corrosion types caused predominantly by either mass transport or wear, according to the nature and intensity of the flow. The relationships between flow rate and corrosion rate can be evaluated as diagnostic criteria. In addition to a synopsis of the information available on the basic processes for copper, aluminium and steel, an attempt is made to classify the various types of flow-dependent corrosion in relation to existing standards for corrosion and wear.Wand-, Stromungs-und Korrosionsgeometrie sind miteinander verkniipft und fiihren je nach Art und Intensitat der Stromung zu den vorwiegend stofftransport-oder verschleiabedingten Korrosionserscheinungen. Die Zusammenhange zwischen Stromungsgeschwindigkeit und Korrosionsrate lassen sich als mechanistisches Unterscheidungskriterium auswerten. Neben einer Zusammenstellung der Kenntnisse iiber die Grundvorgange an Kupfer-, Aluminium-und Eisenwerkstoffen wird eine Einordnung der verschiedenen Arten stromungsabhangiger Korrosion in bestehende Korrosionsund Verschleihormen vorgenommen.

Erosion in Disturbed Liquid/Particle Pipe Flow: Effects of Flow Geometry and Particle Surface Roughness

“…The test cell of tubular type 304 SS (UNS S30400) (1) was positioned in a vertical leg of a slurry flow loop, with an entry length of 50 diam ( Figure 1). The flow loop was composed of a rubber-lined centrifugal pump, a magnetic flow meter, a double-pipe heat exchanger, and steel wire-reinforced tubing.…”

“…As reported by Lotz and Heitz, high local erosion rates can lead to substantial changes in wall geometry, which in turn modifies the structure of the flow and leads to different rates of erosion. 1 The effect of changing wall geometry has been observed in industrial equipment and must be taken into account in experimental studies to determine erosion rates and in predictive models being developed to calculate erosion rates. 2,3 Another important time-dependent effect, especially in test systems, has been modification of the erosiveness of suspended particles.…”

Advanced models for erosion corrosion and its mitigation

“…Once destructed the protectivity of the scale is lost. The corrosion rate increases abruptly and finally becomes purely mass transport controlled according to the boundary conditions of a scale‐free system 4, 7.…”

Erosionskorrosion von Eisenwerkstoffen in feststoffhaltigen Flüssigkeiten

“…The results are discussed from the point of view of materials technology, flow mechanics and erosion corrosion mechanisms. ~~ * Auszug aus der Dissertation von T. Kohley [6].…”