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

Abstract

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.

Description

technical field [0001] The present invention relates to a hot-rolled steel sheet for structural parts of automobiles or parts thereof, etc., and a method for preparing the hot-rolled steel sheet, and more particularly, to a hot-rolled steel sheet having excellent hot-press formability and high tensile strength A hot-rolled steel sheet, a shaped product using the hot-rolled steel sheet, and a method for producing the hot-rolled steel sheet and the shaped product. Background technique [0002] Recently, the automotive industry has produced lighter-weight automotive structures and components thereof with high tensile strength in order to comply with environmental regulations and ensure passenger safety. Therefore, an attempt has been made to develop a method for producing a steel sheet having excellent formability and high tensile strength with the aim of providing the steel sheet with high tensile strength. [0003] In order to achieve the excellent formability and high tensi...

AI Technical Summary

Problems solved by technology

[0004] However, this hot press forming method has a problem in that the cost burden is necessarily high because its productivity is low and the cold rolled steel sheet used in the hot press forming method is expensive.

Images