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US 2026/0097428 A1Published application
Cold rolled steel sheet for hot-press forming having excellent surface quality, hot-press-formed member, and method for manufacturing same
AssigneePosco
InventorsSea-Woong Lee, Jin-Keun Oh, Seong-Woo Kim, Sang-Heon Kim, Sang-Cheol Lee, Kwon-Il Kim
Life of this patent
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Abstract
The present invention relates to a cold rolled steel sheet for hot-press forming, a hot-press-formed member, and a method for manufacturing same and, more specifically, to a cold rolled steel sheet for hot-press forming, having excellent surface quality, a hot-press-formed member, and a method for manufacturing same.
Claims21
1-20. (canceled)
A cold-rolled steel sheet comprising:
- a base steel sheet and a first oxide layer formed on the base steel sheet,
- wherein the first oxide layer comprises two or more of Fe, Mn, Cr, and Si, and has a thickness of 5 to 500 nm.
A member comprising:
- a base steel sheet;
- a first oxide layer formed on the base steel sheet;
- and a second oxide layer formed on the first oxide layer, wherein the first oxide layer comprises two or more of Fe, Mn, Cr, and Si, and the second oxide layer is formed of an Fe-based oxide and has a thickness of 0.1 to 10 μm.
A manufacturing method of a cold-rolled steel sheet, comprising:
- reheating a steel slab;
- hot rolling the reheated steel slab;
- cooling and coiling the hot-rolled steel sheet;
- cold rolling the coiled steel sheet;
- and
- performing continuous annealing on the cold-rolled steel sheet,
- wherein during the continuous annealing, a temperature increase rate at an atmosphere temperature of room temperature to 700° C. is 3.0 to 20.0° C./s, a temperature increase rate at an atmosphere temperature of 700 to 800° C. is 0.08 to 1.5° C./s, a temperature increase rate at an atmosphere temperature of 800 to 900° C. is 0.01 to 1.5° C./s, and a temperature increase rate at an atmosphere temperature of 900 to 1,000° C. is 0.01 to 1.0° C./s.
4 more elements
Dependencies are inferred from the claim text.