| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-strength hot dip galvanized steel sheet having TS (tensile strength) of at least 980 MPa, favorable in formability such as hole expandability, and excellent in energy absorbing power in high speed deformation and a method of manufacturing the same. <P>SOLUTION: In the high-strength hot dip galvanized steel sheet, a composition contains C:0.03-0.13%, Si:1.0-2.0%, Mn:2.4-3.5%, P:0.001-0.05%, S:0.0001-0.01%, Al:0.001-0.1%, N:0.0005-0.01%, B:0.0003-0.01% in mass%, and contents of C, Mn, B satisfy the following formula (1), the residue consists of Fe and obligatory impurities, a structure contains a tempered martensitic phase and a bainitic phase of at least 30% in total area rate (the tempered martensitic phase of at least 30% in total area rate in absence of the bainitic phase), and a maximum proximity distance between the tempered martensitic phases is not more than 10 μm. (%Mn)+1,000×(%B)≥35×(%C) (1). <P>COPYRIGHT: (C)2012,JPO&INPIT |
