MECHANICAL PROPERTIES AND CORROSION PERFORMANCE OF HIGH-STRENGTH BOLTS COVERED WITH METAL COATING GENERATED BY COLD SPRAY TECHNIQUE

Abstract

The high tension bolted joints of steel bridges can be often as weak points in respect of anti-corrosion maintenance. The authors have developed “Smart ZIC (SZ)” method which is coating system spraying metal powder toward the high tension bolted joints for their undercoating by cold spray technology. Metal powder in SZ is collides against base metal surface under its melting temperature point at supersonic speed. Zinc is regarded as undercoating material for the moment. Because metal powder does not reach to its melting point, material qualities of base metal don't change and high density or high adhesive strength of coating layer can be obtained. This paper reports about the outline of SZ and result of basically tests such as salt spray tests, mechanical tests and trial tests at field structures.