Importance

Loading Importance Indicators...

Abstract

A normalizing heat-treated steel sheet having good low-temperature impact toughness and a method for manufacturing the same is provided. The normalizing heat treated steel sheet of the present invention contains, by weight %, C: 0.04 to 0.1%, Si: 0.05 to 0.5%, Mn: 1.0 to 2.0%, Sol. Al: 0.015 to 0.04%, Nb: 0.003 to 0.03%, Ti: 0.005 to 0.02%, Cu: 0.35% or less, Ni: 0.05 to 0.8%, N: 0.002 to 0.008%, P: 0.01% or less (excluding 0%), S: 0.003% or less, and a balance of Fe and unavoidable impurities and has a steel microstructure composed of 70 to 90 area % of polygonal ferrite having a grain size of 20 μm or less, and 10 to 30 area % of spheroidized pearlite.

Loading the Abstract Image...

First Claim