HOT-ROLLED STEEL SHEET WITH EXCELLENT LOW-TEMPERATURE IMPACT TOUGHNESS AND MANUFACTURING METHOD THEREFOR

摘要

Disclosed are a hot-rolled steel sheet having a thickness of 6 mm or more and an excellent impact property, and a manufacturing method thereof.;In accordance with an aspect of the present disclosure, a hot-rolled steel sheet with excellent low-temperature impact toughness includes, in percent (%) by weight of the entire composition, C: more than 0 and 0.03% or less, Si: 0.1 to 1.0%, Mn: more than 0 and 2.0% or less, P: 0.04% or less, Cr: 1.0 to 10%, Ni: more than 0 and 1.5% or less, Ti: 0.01 to 0.5%, Cu: more than 0 and 2.0% or less, N: more than 0 and 0.03% or less, Al: 0.1% or less, the remainder of iron (Fe) and other inevitable impurities, a value of the following Formula (1) satisfies 200 to 1,150, and a microstructure of the cross-section perpendicular to the rolling direction has an average grain size of 50 μm or less in which a misorientation between grains is 5° or more.; 1001.5*C+1150.6*Mn+2000*Ni+395.6*Cu−0.7*Si−1.0*Ti−45*Cr−1.0*P−1.0*Al+1020.5*N  (1)