HIGH-STRENGTH Zn-Al-PLATED STEEL WIRE FOR BRIDGES WHICH HAS EXCELLENT CORROSION RESISTANCE AND FATIGUE PROPERTIES, AND PROCESS FOR PRODUCTION THEREOF

摘要

This is a high-strength Zn-Al coated steel for bridges, steel and plated body layer and comprises a Zn-Al-coated with the Fe-Al-based alloy layer generated at the interface of the steel produced in the surface layer and the plating layer and the body, the composition of the matrix of the steel, by mass%, of C more than 0.70% containing 1.2% or less, Si of 0.01% or more and 2.5% or less, the Mn less than 0.01% and less than 0.9%, the P less than 0.02%, S 0.02%, restricting N to less than 0.01%, and the balance being Fe and unavoidable including impurities, and the composition of the mother phase in the metal structure of the steel wire, and the fresh processing pearlite structure of this kind included in most tissues, the average composition of the Zn-Al plating, by mass%, of Al more than 3.0 containing 15% or less, and limiting the Fe to less than 3.0%, and the thickness of the Fe-Al-based alloy layer produced below 5 . ;