Low-Cost, Corrosion-Resistant Coatings for Steel Rebars and Components

摘要

This research is a follow-on study from a previous SHRP-IDEA project in which acorrosion-resistant Si-Ti coating on steel rebars was produced using fluidized bed technology. The current project scaled up the coating process. A bench-scale reactor system was designed and shown feasible for coating 3-ft long steel rebars. Further research has shown that strong and coherent coating also could be produced by a plasma spray process or simply by spray painting metal powder mixture (along with a flux) followed by low heat treatment (about 600 C). The results demonstrate that corrosion resistance coatings of various metals and alloys such as Si, Ni, Ti, and Ti-Ni can be formed on steel rebars by fluidized bed chemical vapor deposition (FBR-CVD), paint-and-heat, or FBR-plasma spray techniques. The paint-and heat process appears most suitable for commercial application. Data on microstructural characteristics of the coated steel surface and corrosion resistance are presented.