Plated steel sheet for hot press forming having excellent impact property, hot press formed part, and manufacturing method thereof
One aspect of the present invention relates to a plated steel sheet for hot press forming, having an excellent impact property.
1. A hot press formed part comprising:
a base material;
a plated layer comprising aluminum (Al) on the base material; and
a carbon-enriched region is formed in a surface layer region of the base material,
wherein the carbon-enriched region means a region which the carbon content is 110% or more of an average carbon amount (C 0 ) of the base material,
wherein the surface layer region means a region from an interface between the base material and the plated layer to a depth of 200 μm wherein the interface between the base material and the plated layer means a point at which aluminum (Al) content is 1 wt %,
wherein the aluminum (Al) content is analyzed by a Glow Discharge Spectrometer (GDS) method, and
wherein a thickness of the carbon-enriched region is 150 μm or less.
2. The hot press formed part of claim 1 , wherein the thickness of the carbon-enriched region is 10 μm or more.
3. The hot press formed part of claim 1 , wherein a microstructure of the base material comprises 10% or less of ferrite phase.
4. The hot press formed part of claim 1 , wherein the base material comprises, by wt %, 0.15-0.4% of C, 0.1-1.0% of Si, 0.6-3.0% of Mn, 0.001-0.05% of P, 0.0001-0.02% of S, 0.01-0.1% of Al, 0.001-0.02% of N, 0.001-0.01% of B, 0.01-0.5% of Cr, 0.01-0.05% of Ti, and the balance of Fe and inevitable impurities.
5. The hot press formed part of claim 4 , wherein the base material further comprises, by wt %, at least one selected from Mo, Nb, and V in such a manner that a sum thereof is 0.05 to 0.5 wt %.
6. The hot press formed part of claim 1 , wherein the hot press formed part has tensile strength (TS) of 1300 MPa or more and impact absorption energy (IE) of 4.0 J or more measured using a sample having a thickness of 1.5 mm at 25° C.
7. The hot press formed part of claim 1 , wherein the hot press formed part has a product (TS×IE) of tensile strength (TS) and impact absorption energy (IE), measured using a sample having a thickness of 1.5 mm at 25° C., greater than or equal to 8000 MPa·J.
8. The hot press formed part of claim 1 , wherein the thickness of the carbon-enriched region is 21 μm to 150 μm.
9. The hot press formed part of claim 8 , wherein the thickness of the carbon-enriched region is 40 μm to 150 μm.
10. The hot press formed part of claim 9 , wherein the thickness of the carbon-enriched region is 51 μm to 150 μm.
11. A hot press formed part comprising:
a base material;
a plated layer comprising aluminum (Al) on the base material; and
a carbon-enriched region is formed in a surface layer region of the base material,
wherein the carbon-enriched region means a region which the carbon content is 110% or more of an average carbon amount (C 0 ) of the base material,
wherein the surface layer region means a region from an interface between the base material and the plated layer to a depth of 200 μm
wherein the interface between the base material and the plated layer means a point at which aluminum (Al) content is 1 wt %,
wherein the aluminum (Al) content is analyzed by a Glow Discharge Spectrometer (GDS) method, and
wherein the carbon-enriched region is spaced from the interface between the base material and the plated layer.
12. The hot press formed part of claim 11 , wherein the thickness of the carbon-enriched region is 10 μm or more and 150 μm or less.
13. The hot press formed part of claim 11 , wherein a microstructure of the base material comprises 10% or less of ferrite phase.
14. The hot press formed part of claim 11 , wherein the base material comprises, by wt %, 0.15-0.4% of C, 0.1−1.0% of Si, 0.6−3.0% of Mn, 0.001−0.05% of P, 0.0001−0.02% of S, 0.01−0.1% of Al, 0.001-−0.02% of N, 0.001−0.01% of B, 0.01−0.5% of Cr, 0.01−0.05% of Ti, and the balance of Fe and inevitable impurities.
15. The hot press formed part of claim 14 , wherein the base material further comprises, by wt %, at least one selected from Mo, Nb, and V in such a manner that a sum thereof is 0.05 to 0.5 wt %.
16. The hot press formed part of claim 11 , wherein the hot press formed part has tensile strength (TS) of 1300 MPa or more and impact absorption energy (IE) of 4.0 J or more measured using a sample having a thickness of 1.5 mm at 25° C.
17. The hot press formed part of claim 11 , wherein the hot press formed part has a product (TS×IE) of tensile strength (TS) and impact absorption energy (IE), measured using a sample having a thickness of 1.5 mm at 25° C., greater than or equal to 8000 MPa·J.
18. The hot press formed part of claim 11 , wherein the thickness of the carbon-enriched region is 21 μm to 150 μm.
19. The hot press formed part of claim 18 , wherein the thickness of the carbon-enriched region is 40 μm to 150 μm.
20. The hot press formed part of claim 19 , wherein the thickness of the carbon-enriched region is 51 μm to 150 μm.