HIGH-HARDNESS STEEL SHEET, AND MANUFACTURING METHOD THEREOF

• Main Authors: IM, Young-Roc, JANG, Jun-Sang
• Format: Patent
• Language: English; French; German
• Published: 22.05.2024
• 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

The objective of one aspect of the present invention is to provide a high-hardness steel sheet and a manufacturing method, the high-hardness steel sheet having Brinell hardness of 500 HB or more by setting a steel composition according to a minimum carbon content relation (1). Another aspect of the present invention relates to, as a high-hardness steel sheet having Brinell hardness of 500 HB or more and to be manufactured by comprising a process of cooling a hot rolled steel sheet, a high-hardness steel sheet having a minimum carbon (C) content which meets the following relation (1), having a microstructure comprising 95 vol% or more of martensite phase, and having Brinell hardness of 500 HB or more; and a manufacturing method therefor. Cminimumcarbonccontent≥0.481−0.104Mn−0.035Si−0.088Cr−0.054Ni−0.035Mo−0.0003C.R. (wherein Mn, Si, Cr, Ni and Mo are a value representing the content of each element by wt%, and C.R. is a value represent cooling rate during cooling a hot rolled steel sheet and the unit thereof is °C /sec)