Studies on Corrosion Resistance of Hot Dipping Aluminized Steel Wire

The corrosion resistance of hot dipping aluminized steel wire in regard to the effects of additive elements in aluminum bath was studied in comparison with that of galvanized steel wire. According to the above fundamental studies, exposure tests were performed on the aluminized wire with Mn-Al-alloy, the alloy of the highest corrosion resistance, in comparison with galvanized wire in various districts.The results obtained are summarized as follows:(1) In the aqueous solution of pH less than 11, the corrosion resistance of aluminized wire was higher than that of galvanized wire; while, in the solution of pH more than 11, the resistance of the former was lower than that of the latter.(2) In the aqueous solution of 1% HCl, the addition of Mn gave no bad effects on the corrosion resistance of the aluminized wire: though the addition of Si, Ti, Be, etc. gave bad effects. The resistance of aluminized wire with various Al-alloys was remarkably higher than that of galvanized wire.(3) The results of corrosion resistance in the aqueous solution of 1% NaOH of aluminized wire were much lower than those of galvanized wire, but the addition of Si, Ti, Be, or Mn improved the above results.(4) The results of corrosion resistance in salt spray test of aluminized wire were higher than those of galvanized wire, and the addition of one of the above elements more improved the results.(5) The corrosion of galvanized steel wire in A.C.S.R. was advanced by the contact with aluminum wire: while, the corrosion of aluminized steel wire in A.C.S.R. was less than the case of without contact, but rather prevented by aluminizing.(6) According to the results of salt water immersion test and exposure tests in industrial area, seaside district, and volcanic or hot spring zone, the corrosion resistance of aluminized (with 1.5% of Mn-Al alloy) steel wire was always higher than that of galvanized steel wire.