Partial repair of thermally sprayed and sealed corrosion protection - Organic coating material or thermal spraying?

摘要

For many decades thermally sprayed corrosion protection systems on the basis of ZnAl or Al carry out their service for structures in coastal areas, the offshore sector, as CUI (corrosion protection under insulation) or anywhere, where the properties of thermally sprayed corrosion protection systems bring important advantages in terms of durability. A thermally sprayed corrosion protection system is about to protect the structure for 25 to 30 years against corrosion. During this time it may be damaged due to factors like construction work, improper handling or simple aging. There are many standards and regulations which describe the initial design of thermal spray systems, however, there cannot be found any information regarding repair. In particular, a mending of partial regions is hardly described. Specific repair instructions are rare and if present, they differ from one another. Overall there is a lack of knowledge of the proper procedures for partial repair of thermally sprayed coating systems. This project was concerned with tangible corrosion technical issues of the coating repairs: How does the critical overlap area perform? Have organic coatings benefits? To what extent does a renewed damage affect the lifetime? The aim of this study was to develop practice relevant instructions for the repair of thermally sprayed duplex systems.