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Permanent link (DOI): https://doi.org/10.7939/R3S895
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Erosion-corrosion of 304 stainless steel Open Access
- Other title
single particle impact
- Type of item
- Degree grantor
University of Alberta
- Author or creator
- Supervisor and department
Luo, Jingli (Chemical and Materials Engineering, University of Alberta)
- Examining committee member and department
Thomas H. Etsell (Chemical and Materials Engineering, University of Alberta)
John A. Nychka (Chemical and Materials Engineering, University of Alberta)
Zihui Xia (Meahcnical Engineering, University of Alberta)
Akram M. Alfantazi(Materials Engineering, University of British Columbia)
Department of Chemical and Materials Engineering
- Date accepted
- Graduation date
Doctor of Philosophy
- Degree level
Stainless steel is one of the most commonly used materials in most industries. Excellent corrosion resistance of stainless steel is due to the formation of an oxide film on the surface (passive film), which protects the material from continuous corrosion attacks. When subjected to an attack combining corrosion and erosion, the passive film is damaged and thus, higher and unpredictable degradation rates are observed, which may result in costly consequences.
In the first part of this study a model was developed for erosion enhanced corrosion of 304 stainless steel. A new device was designed and constructed, which made possible the impingement of single particles on the surface of sample material at different impact velocities and angles. Based on the electrochemical response of material to the impact of single particles, a model was proposed that considered the number of the impacting particles on the surface. The predictions made by this model were later compared with the results of a slurry jet experiment, which was used to simulate the service conditions.
The second part of the research included the basic mechanical and electrochemical studies of the interactions occurring between the particle and material surface during the particle impact. This included the effects of different impact parameters such as coefficient of friction, impact angle, impact energy and particle angular velocity on depassivation of 304 stainless steel and its erosion-corrosion. A depassivation mechanism was proposed that considered a combined effect of the friction force and its effective path of action on the surface.
In the last part improving the erosion-corrosion properties of 304 stainless steel was tried based on the results of the second part of the study. Samples were cold rolled and the effect of hardness on the coefficient of friction was investigated, which in the second part was proven responsible for the depassivation of the surface. It was found that the coefficient of friction between the particles and the surface remains unchanged in different applied percentages of cold work. Also it was shown that work hardening is an effective method for increasing the resistance of the material to erosion-corrosion.
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File title: University of Alberta