Chapter 6: Corrosion Prevention: Design, Coatings & Protection

Corrosion Prevention: Design, Coatings & Protection begins by emphasizing the critical importance of strategic materials selection, debunking common myths about stainless steels while highlighting the specific utility of metals like tantalum, aluminum, and various nonmetallics such as ceramics, polymers, and carbons. Beyond material choice, the text explores environmental alteration techniques, including the modification of temperature, fluid velocity, and the removal of corrosive agents like oxygen through deaeration or the use of scavengers. A significant portion of the discussion focuses on the application of chemical inhibitors—ranging from adsorption-type organic compounds to vapor-phase substances—and the vital role of structural design in avoiding pitfalls like galvanic contact, crevice formation, and poor drainage. The chapter provides a deep dive into electrochemical protection methods, contrasting traditional cathodic protection, which utilizes sacrificial anodes or impressed currents to suppress metal dissolution, with the technique of anodic protection that uses potentiostats to stabilize the passive films of active-passive alloys. Finally, the chapter details a vast array of protective coatings, covering metallic processes such as electroplating, cladding, and hot dipping, alongside organic solutions like high-performance paints, stressing the absolute necessity of rigorous surface preparation for long-term coating adherence and effectiveness.