| 摘要 |
<p>A hot-dip metal coated high-strength steel sheet for press working which has a tensile strength of 380MPa or above but below 540MPa and press formabi lity suitable for automotive use, particularly fuel tanks and which is excel lent in the resistance to secondary operation embrittlement, the low-tempera ture toughness of seam welds, and the properties of plating; and a process f or the production of the steel sheet. A hot-dip metal coated high-strength s teel sheet for press working which comprises both a cold-rolled steel sheet and a hot-dip plating layer formed on the surface of the steel sheet, charac terized in that the cold-rolled steel sheet contains by mass C: 0.0005 to 0. 0050%, Si: more than 0.3 to 1.0%, Mn: 0.70 to 2.0%, P: 0.05% or below, Ti: 0 .010 to 0.050%, Nb: 0.010 to 0.040%, B: 0.0005 to 0.0030%, S: 0.010% or belo w, Al: 0.01 to 0.90% and N: 0.0010 to 0.01% and has TB* of 0.03 to 0.06 as d efined by the formula while satisfying the relationship , wherein [Ti] is Ti content (%); [B] is B content (%); and [P] is P content (%). TB* = (0.11 - [Ti])/(ln([B] x10000))</p> |
