120-kg-grade ultrahigh-strength galvanized steel sheet and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-2025389007-A1
Application number	US-202318879784-A
Country	US
Kind code	A1
Filing date	Jun 30, 2023
Priority date	Jun 30, 2022
Publication date	Dec 25, 2025
Grant date	—

Abstract

Provided in the present invention is a 120-kg-grade ultrahigh-strength galvanized steel sheet with a good resistance spot welding performance. The galvanized steel sheet comprises: 0.18-0.24% of C, 2.3-3.0% of Mn, 0.5-1.7% of Si, 0.02-1.0% of Al, 0.550.

First claim

1 . A 120 Kg grade ultra-high strength galvanized steel plate, which comprises the following chemical elements:

C
:

0.18
-
0.24
%

,

Mn
:

2.3
-
3.
%

,

Si
:

0.5
-
1.7
%

,

Al
:

0.02
-
1.
%

,

0.55
<

Si
+
Al

≤

1.75
%

,

C
+

Si
/
30

+

Mn
/
20

≤

0.395
%

,

at least one of Nb, Ti, B, Cr, Mo and REM,
and a balance of Al and unavoidable impurities, wherein
the thickness of the steel plate is set to t, the resistivity R 1 of the steel plate is 0<R 1 ≤55 μΩ·cm;
in the direction from the interface between the plating layer and the steel plate matrix to the steel plate matrix, the resistivity R 2 of the steel plate in the range of 0.025 t to 0.05 t is 0<R 2 ≤15 μΩ·cm, and the resistivity R 3 of the steel plate in the range of 0.01 t to 0.015 t is 0<R 3 ≤35 μΩ·cm, and they satisfy 1.5R 1 1/2 -0.1R 2 -0.25R 3 >0.

2 . A 120 Kg grade ultra-high strength galvanized steel plate, which comprises the following chemical elements in addition to Fe and other unavoidable impurities:

C
:

0.18
-
0.24
%

,

Mn
:

2.3
-
3.
%

,

Si
:

0.5
-
1.7
%

,

Al
:

0.02
-
1.
%

,

0.55
<

Si
+
Al

≤

1.75
%

,

C
+

Si
/
30

+

Mn
/
20

≤

0.395
%

,

at least one of Nb, Ti, B, Cr, Mo and REM,
wherein,
the thickness of the steel plate is set to t, the resistivity R 1 of the steel plate is 0<R 1 ≤55 μΩ·cm;
in the direction from the interface between the plating layer and the steel plate matrix to the steel plate matrix, the resistivity R 2 of the steel plate in the range of 0.025 t to 0.05 t is 0<R 2 ≤15 μΩ·cm, and the resistivity R 3 of the material in the range of 0.01 t to 0.015 t is 0<R 3 ≤35 μΩ·cm, and they satisfy 1.5R 1 1/2 -0.1R 2 -0.25R 3 >0.

3 . The 120 Kg grade ultra-high strength galvanized steel plate according to claim 1 , wherein the contents of Nb, Ti, B, Cr, Mo and REM are as follows:

0
≤
Nb
≤

0.1
%

;

0
≤
Ti
≤

0.1
%

;

0
≤
B
≤

0.003
%

;

0
≤
Cr
≤

0.1
%

;

0
≤
Mo
≤

0.1
%

;

0
≤
REM
<

0.05

%
.

4 . The 120 Kg grade ultra-high strength galvanized steel plate according to claim 3 , wherein, if present, the contents of Nb, Ti, B, Cr, Mo and REM are as follows:

Nb
:

0.08
-
0.1
%

;

Ti
:

0.01

Assignees

• Baoshan Iron & Steel

Inventors

• Chen Meng
• Bi Wenzhen
• Zhong Yong
• Wang Li

Classifications

• C21D8/02

  during manufacturing of plates or strips (C21D8/12 takes precedence) · CPC title

• C21D2211/008

  Martensite · CPC title

• C21D2211/001

  Austenite · CPC title

• C21D1/74

  Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material · CPC title

• C21D1/26

  Methods of annealing · CPC title