US 2025/0019812 A1 · HOT-ROLLED STEEL SHEET AND METHOD FOR MANUFACTURING SAME

Abstract

An embodiment of the present invention provides a hot-rolled steel sheet comprising, by wt %, 0.06-0.12% of C, 0.004-0.4% of Si, 0.8-2.0% of Mn, 0.01-0.05% of Al, 0.05-1.0% of Cr, 0.001-0.3% of Mo, 0.001-0.05% of P, 0.001-0.005% of S, 0.001-0.01% of N, 0.001-0.05% of Nb, 0.001-0.05% of Ti, 0.001-0.005% of B, and the remainder of Fe and other inevitable impurities, satisfying relational formula 1 below, and having a microstructure including, by area, 80% or more of auto-tempered martensite, and a remainder of at least one of fresh martensite, bainite, and ferrite. [Relational formula 1] (10[C]+[Si]+2.5[Mn])/(1.5[Cr]+2.0[Mo]−3.2[Nb])≤20

Claims8

Dependent claims

A hot-rolled steel sheet comprising, by weight:

0.06 to 0.12% of C, 0.004 to 0.4% of Si,0.8 to 2.0% of Mn, 0.01 to 0.05% of Al, 0.05 to 1.0% of Cr, 0.001 to 0.3% of Mo, 0.001 to 0.05% of P, 0.001 to 0.005% of S, 0.001 to 0.01% of N, 0.001 to 0.05% of Nb, 0.001 to 0.05% of Ti, 0.001 to 0.005% of B, with a remainder of Fe and other inevitable impurities, satisfying Relational Expression 1 below, and having a microstructure including, by area, 5 to 15% of austenite, 80% or more of auto-tempered martensite, and a remainder of at least one of bainite and ferrite,
(
10
[
C
]
+
[
S
⁢
i
]
+
2
.
5
[
M
⁢
n
]
)
/
(
1.
5
[
C
⁢
r
]
+
2
.
0
[
M
⁢
o
]
-
3
.
2
[
N
⁢
b
]
)
≤
20.
[
Relational
⁢
Expression
⁢
1
]

56 more elements

Dependencies are inferred from the claim text.

Hot-rolled steel sheet and method for manufacturing same

Life of this patent

Hot-rolled steel sheet and method for manufacturing same

Life of this patent

Abstract

Claims8