High strength hot dipped galvanized steel sheet and high strength alloyed hot dipped galvanized steel sheet each having tensile strength of 980 mpa or more excellent plating adhesion excellent formability and excellent bore expanding properties and method for producing same

摘要

pA high strength hot dipped galvanized steel sheet which has a tensile strength of 980 MPa or more while having excellent plating adhesion formability and bore expanding properties. This high strength hot dipped galvanized steel sheet has a hot dipped zinc plating layer on the surface of a matrix steel sheet and the matrix steel sheet contains in mass% 0.05 0.4% of C 0.01 3.0% of Si 0.1 3.0% of Mn and 0.01 2.0% of Al while satisfying Si + Al 0.5% and suppressing P to 0.04% or less S to 0.05% or less and N to 0.01% or less with the balance made up of iron and unavoidable impurities. The microstructure of the matrix steel sheet contains 40% by volume or more of martensite and bainite in total 8% by volume or more of residual austenite with the balance made up of ferrite or ferrite and 10% by volume or less of pearlite. The martensite contains two or more of the three kinds of martensite (1) (2) and (3) in an amount of 10% by volume or more in total and the hot dipped zinc plating layer contains less than 7% by mass of Fe./p