NORMALIZING HEAT TREATED STEEL SHEET HAVING GOOD LOW IMPACT TOUGHNESS AND METHOD FOR MANUFACTURING SAME

• Main Authors: KIM, Woo-Gyeom, YUN, Ki-Ho, BAEK, Dae-Woo
• Format: Patent
• Language: English; French; German
• Published: 19.06.2024
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

A normalizing heat treated steel sheet having good low impact toughness and a method for manufacturing the same are 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 the balance of Fe and unavoidable impurities, and has a steel microstructure consisting 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.