Patent ID: 7572407

Claim:
A welded vehicle structural component having a welding heat-affected zone comprising: a martensitic stainless steel sheet having superior workability comprising, on a mass basis, less than about 0.02% of carbon; about 1.0% or less of silicon; less than about 1.5% of manganese; about 0.04% or less of phosphorus; about 0.01% or less of sulfur; about 0.05% or less of aluminum; about 1.5% or more and less than about 4.0% of nickel; more than 13.0% and less than about 15% of chromium; about 0.5% to less than 1.5% of molybdenum; and less than about 0.02% of nitrogen, the balance being iron and unavoidable impurities, wherein relationships (1) to (4) are satisfied: 15.0%≦[Cr]+1.5×[Mo]+1.2×[Ni]≦20.0% (1) [C]+[N]<0.030% (2) [Ni]+0.5×([Mn]+[Mo])+30×[C]>3.0% (3) 8.0%≦72×[C]+40×[N]+3 ×[Si]+2×[Mn]+4×[Ni]+[Mo]≦18.0% (4). wherein the steel sheet is 1) a cold rolled steel sheet having a thickness of 0.3-3.0 mm or 2) a hot rolled steel sheet having a thickness of 1.5-8.0 mm and generates a Charpy impact value of the welding heat-affected zone at −50° C. of 50J/cm 2 or more and a tensile strength of more than about 600 MPa.