Hot stamping component and manufacturing method therefor
A hot stamping component according to an embodiment of the present disclosure includes a steel sheet, a plating layer located on the steel sheet and including Zn, and a surface layer located on the plating layer, wherein the surface layer includes a post-treatment layer including an Si-based inorganic post-treatment agent, a Zn oxide layer located on a same layer as the post-treatment layer on the plating layer, and an inter-diffusion layer located between the plating layer and at least one of the post-treatment layer and the Zn oxide layer to overlap at least one of the post-treatment layer and the Zn oxide layer, the inter-diffusion layer including at least one of Si, Mn, O, Fe, Zn, and SiO, wherein a tensile strength of the steel sheet is 1680 MPa or more.
1 . A hot stamped component comprising:
a steel sheet;
a plating layer located on the steel sheet and comprising Zn; and
a surface layer located on the plating layer, wherein the surface layer comprises:
an Si layer comprising an Si-based inorganic agent;
a Zn oxide layer wherein both the Si layer and the Zn oxide layer are on the plating layer; and
an inter-diffusion layer located between the plating layer and at least one of the Si layer and the Zn oxide layer, the inter-diffusion layer extending into at least one of the Si layer and the Zn oxide layer and comprising at least one of Si, Mn, O, Fe, Zn, and silicon oxide,
wherein an area ratio of the inter-diffusion layer to the Si layer is at least 10% but not more than 80%, and
wherein a tensile strength of the hot stamped component is 1680 MPa or more.
2 . The hot stamped component of claim 1 , wherein the Si layer comprises at least one of Si, Mn, O, Fe, Zn, and silicon oxide as components diffused from the steel sheet and the plating layer, and an oxide of the Si-based inorganic agent.
3 . The hot stamped component of claim 1 , wherein an average thickness of the Si layer is less than an average thickness of the Zn oxide layer,
wherein the average thickness of the Si layer is 5% or more and less than 100% of the average thickness of the Zn oxide layer.
4 . The hot stamped component of claim 3 , wherein the average thickness of the Si layer ranges from 0.5 μm to 3 μm, and
the average thickness of the Zn oxide layer ranges from 1 μm to 10 μm.
5 . The hot stamped component of claim 4 , wherein an average thickness of the inter-diffusion layer ranges from 0.1 μm to 2 μm.
6 . A method of manufacturing a hot stamped component, the method comprising:
applying an Si-based inorganic agent on a zinc-containing plating layer of a steel sheet and drying the applied Si-based inorganic agent to form a pre-post-treatment laver;
heating the steel sheet in a furnace for about 120 seconds to about 600 seconds, wherein during the heating a temperature of the steel sheet increases from about 700° C. to a temperature in a range of about Ac3 to about 910° C. at an average heating rate of about 1.5° C./second to about 7° C./second, thereby forming a surface layer on the plating layer comprising a Si layer and a Zn oxide layer, and forming an inter-diffusion layer at an interface between the plating layer and at least one of the Si layer and the Zn oxide layer, the inter-diffusion layer extending into at least one of the Si layer and the Zn oxide layer and comprising at least one of Si, Mn, O, Fe, Zn, and silicon oxide; and
hot stamping the heated steel sheet to form the hot stamped component;
wherein the Si-based inorganic agent is applied to the steel sheet to a thickness of 0.5 μm to 3 μm to form the pre-post-treatment layer,
wherein an amount of the applied Si-based inorganic agent is 0.5 g/m 2 to 3 g/m 2 , and
wherein a tensile strength of the hot stamped component is 1680 MPa or more.
7 . The method of claim 6 , wherein an area ratio of the inter-diffusion layer to the Si layer is at least 10% but not more than 80%.
8 . The method of claim 7 , wherein the Si layer comprises at least one of Si, Mn, O, Fe, Zn, and silicon oxide as components diffused from the steel sheet and the plating layer, and an oxide of the Si-based inorganic agent.
9 . The method of claim 6 , wherein an average thickness of the Si layer is less than an average thickness of the Zn oxide layer,
wherein the average thickness of the Si layer is 5% or more and less than 100% of the average thickness of the Zn oxide layer.
10 . The method of claim 9 , wherein the average thickness of the Si layer ranges from 0.5 μm to 3 μm, and
the average thickness of the Zn oxide layer ranges from 1 μm to 10 μm.
11 . The method of claim 10 , wherein an average thickness of the inter-diffusion layer ranges from 0.1 μm to 2 μm.
12 . The method of claim 6 , wherein the Si-based inorganic agent is applied to the steel sheet and dried at a temperature of 70° C. to 150° C. for 1 second to 10 seconds.