High strength galvanized steel plate excellent in adhesion of plated metal and formability in press working and high strength alloy galvanized steel plate and method for production thereof
First Claim
1. A high strength hot-dip galvanized steel sheet with excellent plating adhesion and press formability, the steel sheet containing in terms of weight percent,C:
- 0.05-0.2%, Si;
0.2-2.0%, Mn;
0.2-2.5%, Al;
0.01-1.5%, Ni;
0.2-5.0%, P;
<
0.03% and S;
<
0.02% where the relationship between Si and Al is such that 0.4(%)≦
Si(%)+0.8 Al(%)≦
2.0% and the remainder consists of Fe and unavoidable impurities, characterized in that the volume percentage of the retained austenite in the steel sheet is 2-20% and the steel sheet surface wherein the relationship between the Ni and Si, Al in 0.5 μ
m of the steel sheet surface layer is such that Ni(%)≧
¼
Si(%)+⅓
Al(%), has a Zn plating layer comprising Al;
≦
1% with the remainder Zn and unavoidable impurities.
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Accused Products
Abstract
The invention relates to a high strength hot-dip galvanized and galvannealed steel sheets with excellent drawability for press forming and excellent plating adhesion that is useful as a member for automobiles, construction, electric devices and the like, and to a process for its manufacture. According to an embodiment of the invention, the steel sheet contains in terms of weight percent, C: 0.05-0.2%, Si: 0.2-2.0%, Mn: 0.2-2.5%, Al: 0.01-1.5%, Ni: 0.2-5.0%, P: <0.03% and S: <0.02%, the relationship between Si and Al being such that 0.4(%)≦Si+0.8 Al(%)≦2.0% and the remainder consisting of Fe and unavoidable impurities, the volume percentage of the retained austenite is 2-20% and the steel sheet surface wherein the relationship between the Ni and Si, Al in 0.5 μm of the steel sheet surface layer is such that Ni(%)≦¼ Si+⅓Al(%), has a Zn plating layer comprising Al: ≦1% with the remainder Zn and unavoidable impurities.
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Citations
15 Claims
-
1. A high strength hot-dip galvanized steel sheet with excellent plating adhesion and press formability, the steel sheet containing in terms of weight percent,
C: - 0.05-0.2%,
Si;
0.2-2.0%,Mn;
0.2-2.5%,Al;
0.01-1.5%,Ni;
0.2-5.0%,P;
<
0.03% andS;
<
0.02%where the relationship between Si and Al is such that 0.4(%)≦
Si(%)+0.8 Al(%)≦
2.0% and the remainder consists of Fe and unavoidable impurities, characterized in that the volume percentage of the retained austenite in the steel sheet is 2-20% and the steel sheet surface wherein the relationship between the Ni and Si, Al in 0.5 μ
m of the steel sheet surface layer is such that Ni(%)≧
¼
Si(%)+⅓
Al(%), has a Zn plating layer comprising Al;
≦
1% with the remainder Zn and unavoidable impurities.- View Dependent Claims (2, 3, 4, 5, 6, 13)
- 0.05-0.2%,
-
7. A high strength alloyed hot-dip galvannealed steel sheet with excellent press formability, characterized in that a steel sheet containing in terms of weight percent,
C: - 0.05-0.2%,
Si;
0.2-2.0%,Mn;
0.2-2.5%Al;
0.01-1.5%,Ni;
0.2-5.0%.P;
<
0.03% andS;
<
0.02%,where the relationship between Si and Al is such that 0.4(%)≦
Si(%)+0.8 Al(%)≦
2.0%, the remainder consists of Fe and unavoidable impurities, the volume percentage of the retained austenite in the steel sheet is 2-20% and the relationship between the Ni and Si, Al in 0.5 μ
m of the steel sheet surface layer is such that Ni(%)≧
¼
Si(%)+⅓
Al(%), has a Zn alloy plating layer comprising Fe;
8-15%, Al;
≦
1% with the remainder Zn and unavoidable impurities.- View Dependent Claims (8, 9, 10, 11, 12, 14, 15)
- 0.05-0.2%,
Specification