Patent ID: 8703241

Claim:
A method of batch hot-dip galvanizing steel parts, wherein the steel parts are a) degreased into an acidic aqueous 10 wt % solution, at room temperature for 10 minutes; b) rinsed into tap-water; c) pickled into HCl 10 wt %, at room temperature for 15 minutes; d) rinsed into tap-water; e) immersed into an aqueous flux solution, based on chlorides and containing bismuth chloride, said aqueous flux solution containing 50-300 g/L ZnCl 2 , 20-300 g/L NH 4 Cl, 0.1-1 g/L Bi 2 O 3 , 10-100 g/L KCl and having a pH between 0.5 and 1.0, adjusted by adding HCl or KOH 0.1N, and having a temperature between 3 and 50° C., the immersion time being between 10 seconds and 10 minutes; f) dried in warm air at 60-120° C. and g) hot-dip galvanized into an alloy containing mainly zinc and 0.01 wt %-0.1 wt % of aluminium.