HOT ROLLED STEEL SHEET HAVING SUPERIOR HOT PRESS FORMING PROPERTY AND HIGH TENSILE STRENGTH, FORMED ARTICLE USING THE STEEL SHEET AND METHOD FOR MANUFACTURING THE STEEL SHEET AND THE FORMED ARTICLE

摘要

There are provided a hot rolled steel sheet that has superior hot press forming property and high tensile strength and is used for structural members and their parts of automobiles and the like, a formed article, and a method for manufacturing the hot rolled steel sheet and the formed article. The hot rolled steel sheet having superior hot press forming property and high tensile strength includes, by weight: C: 0.1 to 0.5%, Mn: 1.0 to 3.0%, Si: 0.5% or less, W: 0.1% or less, N: 0.01 to 0.1%, Al: 0.01 to 0.1%, S: 0.03% or less, P: 0.1% or less and B: 0.001 to 0.01%, at least one element selected from the group consisting of Ti: 0.001 to 0.1%, Nb: 0.001 to 0.1% and V: 0.001 to 0.1%, at least one element selected from the group consisting of Mo: 0.01 to 1.5%, Cr: 0.01 to 1.5%, Cu: 0.005 to 1.0% and Ni: 0.005-2.0%, and the balance of iron (Fe) and other inevitable impurities, wherein a structure of the hot rolled steel sheet includes 10% or less of proeutectoid ferrite, 10% or less of pearlite and the balance of bainite, or includes 10% or less of proeutectoid ferrite, 10% or less of pearlite and the balance of bainite and martensite.