ALLOYED HOT-DIP GALVANIZED STEEL SHEET WITH EXCELLENT CORROSION RESISTANCE AFTER COATING

摘要

There are provided a galvannealed steel sheet having high corrosion resistance after painting based on a high-strength steel sheet containing Si and a method for manufacturing the galvannealed steel sheet. The galvannealed steel sheet contains C: 0.05% to 0.30%, Si: 1.0% to 3.0%, Mn: 0.5% to 3.0%, Al: 0.01% to 3.00%, S: 0.001% to 0.010%, and P: 0.001% to 0.100% on a mass percent basis and a remainder of Fe and incidental impurities. The steel sheet includes a galvannealed layer on the surface thereof. The galvannealed layer contains Fe: 7% to 15% and Al: 0.02% to 0.30% and a remainder being Zn and incidental impurities. The percentage of exposed Zn metal of the galvannealed layer surface is 20% or more.