| 摘要 |
<p>For obtaining a hot dip galvannealed steel sheet having high strength and high ductility and excellent phosphatability, a chemical composition of a material steel sheet for forming the hot dip galvannealed steel sheet comprises 0.4 to 2.0 mass % of Si and 1.0 to 3.5 mass % of Mn, and an average Mn concentration for a region from the uppermost surface to 0.01 mum depth in the coating layer is defined as 0.14% or more.</p> |
