IP Library Granted Patent US 10,570,493
Granted Patent B2
US 10,570,493 · App. 15/105,498 · Granted Feb 25, 2020

Steel sheet for hot press forming with excellent corrosion resistance and weldability, forming member, and manufacturing method therefor

Inventors: Myung-Soo Kim (Gwangyang-si, KR); Hyeon-Seok Hwang (Gwangyang-si, KR)
Assignee: POSCO
C23C2/12C22C21/06C22C21/08C22C38/00C23C2/26Y10T428/12736Y10T428/12757
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Quick Facts
Patent No.
US 10,570,493
App. No.
15/105,498
Granted
Feb 25, 2020
Kind
B2
Abstract

The present invention relates to: a steel sheet for hot press forming that is used for vehicle parts and the like and, more particularly, to a steel sheet for hot press forming with excellent corrosion resistance and weldability; a forming member; and a manufacturing method therefor.

Claims (20)

1. A steel sheet for hot press forming, comprising:

a base steel sheet including: 0.1 wt % to 0.4 wt % of carbon (C), 0.05 wt % to 1.5 wt % of silicon (Si), 0.5 wt % to 3.0 wt % of manganese (Mn), one or more selected from a group consisting of 0.001 wt % to 0.02 wt % of nitrogen (N), 0.0001 wt % to 0.01 wt % of boron (B), 0.001 wt % to 0.1 wt % of titanium (Ti), 0.001 wt % to 0.1 wt % of niobium (Nb), 0.001 wt % to 0.01 wt % of vanadium (V), 0.001 wt % to 1.0 wt % of chromium (Cr), 0.001 wt % to 1.0 wt % of molybdenum (Mo), 0.001 wt % to 0.1 wt % of antimony (Sb) and 0.001 wt % to 0.3 wt % of tungsten (W), and iron (Fe) as a residual component thereof, and inevitable impurities; and

an aluminum-magnesium alloy plating layer formed on at least one surface of the base steel sheet,

wherein the aluminum-magnesium alloy plating layer consists of aluminum and magnesium as principal components and 0.0005 wt % to 0.05 wt % of an element having a higher degree of oxidation than a degree of oxidation of magnesium (Mg) included in the aluminum-magnesium alloy plating layer and inevitable impurities,

wherein the element having a higher degree of oxidation than a degree of oxidation of the magnesium (Mg) is one or more selected from a group consisting of beryllium (Be), lithium (Li), and sodium (Na).

2. The steel sheet for hot press forming of claim 1 , wherein the aluminum-magnesium alloy plating layer includes 0.0005 wt % to 0.02 wt % of the element having a higher degree of oxidation than the magnesium (Mg).

3. The steel sheet for hot press forming of claim 1 , wherein the aluminum-magnesium alloy plating layer includes 0.5 wt % to 10 wt % of magnesium (Mg).

4. The steel sheet for hot press forming of claim 1 , wherein the aluminum-magnesium alloy plating layer has an average thickness of 5 μm to 30 μm.

5. A hot press forming member comprising:

a base steel sheet including: 0.1 wt % to 0.4 wt % of carbon (C), 0.05 wt % to 1.5 wt % of silicon (Si), 0.5 wt % to 3.0 wt % of manganese (Mn), one or more selected from a group consisting of 0.001 wt % to 0.02 wt % of nitrogen (N), 0.0001 wt % to 0.01 wt % of boron (B), 0.001 wt % to 0.1 wt % of titanium (Ti), 0.001 wt % to 0.1 wt % of niobium (Nb), 0.001 wt % to 0.01 wt % of vanadium (V), 0.001 wt % to 1.0 wt % of chromium (Cr), 0.001 wt % to 1.0 wt % of molybdenum (Mo), 0.001 wt % to 0.1 wt % of antimony (Sb) and 0.001 wt % to 0.3 wt % of tungsten (W), and iron (Fe) as a residual component thereof, and inevitable impurities;

an aluminum-magnesium alloy plating layer formed on at least one surface of the base steel sheet, wherein the aluminum-magnesium alloy plating layer consists of aluminum and magnesium as principal components and 0.0005 wt % to 0.05 wt % of an element having a higher degree of oxidation than a degree of oxidation of magnesium (Mg) included in the aluminum-magnesium alloy plating layer and inevitable impurities, and wherein the element having a higher degree of oxidation than a degree of oxidation of the magnesium (Mg) is one or more selected from a group consisting of beryllium (Be), lithium (Li), and sodium (Na); and

an oxide film layer formed in an upper part of the aluminum-magnesium alloy plating layer,

wherein the oxide film layer includes an element having a higher degree of oxidation than a degree of oxidation of magnesium (Mg) included in the aluminum-magnesium alloy plating layer.

6. The hot press forming member of claim 5 , wherein the element having a higher degree of oxidation than a degree of oxidation of the magnesium (Mg) is one or more selected from a group consisting of beryllium (Be), calcium (Ca), lithium (Li), and sodium (Na).

7. The hot press forming member of claim 5 , wherein the oxide film layer further comprises one or more of aluminum and magnesium.

8. The hot press forming member of claim 5 , wherein the aluminum-magnesium alloy plating layer has an average thickness of 5 μm to 35 μm, and the oxide film layer has an average thickness of 1 min or less (excluding 0 μm).

9. A method of manufacturing a steel sheet for hot press forming, comprising:

preparing a base steel sheet including: 0.1 wt % to 0.4 wt % of carbon (C), 0.03 wt % to 1.5 wt % of silicon (Si), 0.5 wt % to 3.0 wt % of manganese (Mn), one or more selected from a group consisting of 0.001 wt % to 0.02 wt % of nitrogen (N), 0.0001 wt % to 0.01 wt % of boron (B), 0.001 wt % to 0.1 wt % of titanium (Ti), 0.001 wt % to 0.1 wt % of niobium (Nb), 0.001 wt % to 0.01 wt % of vanadium (V), 0.001 wt % to 1.0 wt % of chromium (Cr), 0.01 wt % to 1.0 wt % of molybdenum (Mo), 0.001 wt % to 0.1 wt % of antimony (Sb) and 0.001 wt % to 0.3 wt % of tungsten (W), and iron (Fe) as a residual component thereof and inevitable impurities; and

forming an alloy plating layer by dipping the base steel sheet in an aluminum-magnesium alloy plating bath,

wherein the alloy plating layer consists of aluminum and magnesium as principal components and 0.0005 wt % to 0.05 wt % of an element having a higher degree of oxidation than a degree of oxidation of magnesium (Mg) included in the aluminum-magnesium alloy plating layer and inevitable impurities and wherein the element having a higher degree of oxidation than a degree of oxidation of the magnesium (Mg) is one or more selected from a group consisting of beryllium (Be), lithium (Li), and sodium (Na).

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 26, 2022
From: POSCO HOLDINGS INC.
To: POSCO CO., LTD
Reel/Frame 061777/0974 →
CHANGE OF NAME Recorded Sep 28, 2022
From: POSCO
To: POSCO HOLDINGS INC.
Reel/Frame 061562/0012 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 17, 2016
From: KIM, MYUNG-SOO; HWANG, HYEON-SEOK
To: POSCO
Reel/Frame 038939/0145 →
Priority Claims (1)
KR 10-2013-0161323 · Dec 23, 2013 · national
Continuity (1)
Related Publication 20170002450A1 · Jan 5, 2017