steel with an electrically isolated zinc silicon dioxide dispersionsueberzug with excellent korrosionsbestaendigkeit.

摘要

A composite zinc-silica electro-galvanized steel sheet excellent in corrosion resistance, having on at least one surface thereof a zinciferous plating layer, preferably in an amount of from 5 to 100 g/m2 per side thereof, into which silica particles are dispersed. The above-mentioned plating layer consists essentially of: silica particles: from 0.1 to 20 wt.%, nitrogen compounds: from 0.0005 to 0.5 wt.% as converted into nitrogen, and the balance being zinc and incidental impurities. The above-mentioned plating layer further additionally contains as required at least one element selected from the group consisting of: iron :from 2 to 80 wt.%, nickel :from 2 to 25 wt.%, cobalt :from 0.1 to 5 wt.%, and chromium :from 0.5 to 20 wt.%. The total amount of the above-mentioned at least one element thus additionally contained is limited to up to 80 wt.%.