Hyundai Steel Company

Hoon-Dong Kim

Man-Been Moon

Hyun-Ho Bok

Kang-Roh Lee

The present disclosure relates to a high strength steel sheet having good wettability, a tensile strength of 590 MPa or more and a strength-ductility balance (TS&#xd7;El) of 16,520 MPa&#xb7;% or more, and a manufacturing method thereof. The high strength steel comprises, in % by weight, C: 0.03&#x2dc;0.1%, Si: 0.005&#x2dc;0.105%, Mn: 1.0&#x2dc;3.0%, P: 0.005&#x2dc;0.04%, S: 0.003% or less, N: 0.003&#x2dc;0.008%, Al: 0.05&#x2dc;0.4%, Mo or Cr satisfying the inequality 10&#x2266;50&#xb7;[Mo %]+100&#xb7;[Cr %]&#x2266;30, at least one of Ti: 0.005&#x2dc;0.020%, V: 0.005&#x2dc;0.050% and B: 0.0005&#x2dc;0.0015%, and the balance of Fe and unavoidable impurities, wherein a microstructure of the steel sheet is a multi-phase structure comprising, in an area ratio of cross-sectional structure, 70% or more ferrite phase having a Vickers hardness Hv of 120&#x2dc;250 and 10% or more martensite phase having a Vickers hardness Hv of 321&#x2dc;555.

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Gyeonggi-do, South Korea

Hoon-Dong Kim