1. Construction of Erosion-Corrosion Maps for Pure Metals in Aqueous Slurries B. D. Jana and M. M. Stack Department of Mechanical Engineering, University of Strathclyde

2. Objectives: Developing mathematical equation for erosion- corrosion problem Developing a performance relationship between all the variables and parameters of erosion- corrosion in aqueous slurries in a map form Easy way of representing such graphs

3. Erosion Corrosion Phenomena Substrate Corrosion film Particle

4. Available Erosion Models at Normal Impact Sundararajan and Shewmon: Hutchings:

5. Available Corrosion Models Activation controlled kinetics (-Butler Volmer Equation) Passivation controlled kinetics (-repassivation rate due to particle impact)

6. Erosion-corrosion Work “… combine wastage due to aqueous corrosion and mechanical erosion process…” “…the total wastage can be significantly higher than the sum of the two processes…”

7. Erosion-corrosion Rate  K E is the synergistic effect and refer to the influence of corrosion on the erosion rate  K C is the additive effect, and refers to the erosion enhancement of the corrosion rate.

8. Active Region For simplification, we neglect the additive effect and synergistic effect. So  K C and  K E is zero

9. Passive Region In the passive region K CO is neglected, only additive effect is considered

10. K C and K E Determination in the Active Region

11.  K C and K E Determination in the Passive Region

12. Regime Map Boundaries Erosion dominated K C /K E  0.1 Erosion corrosion 0.1  K C /K E  1 corrosion erosion 1  K C /K E  10 corrosion dominated K C /K E  10

13. Construction Methodology: Fe at Ph-7

14. Pourbaix Diagram for All the Metals. Fe Ni Cu Al

15. Maps of All the Metals for Ph 7 Fe Ni CuAl

16. Wastage Map Boundary LOW K E-C  1 MEDIUM 1  K E-C  10 HIGH K E-C  10

17. Wastage Map for All the Metals for Ph 7 Al Ni Fe Cu

18. Comparison of Low Wastage of All the Metals-ph 7

19. Conclusions There is a significant difference between the regime and wastage map for all the metals. The variation above is attributed to the differences in tribo-corrosion behaviour. Al suffers high erosion corrosion due its less hardness than the other metals Due to its high immunity, Cu suffers less erosion- corrosion than the other materials, under the conditions modelled.

20. Thank You