Search

KR-20260063613-A - Hot stamping component and method of manufacturing the same

KR20260063613AKR 20260063613 AKR20260063613 AKR 20260063613AKR-20260063613-A

Abstract

The present invention provides a method for manufacturing a hot stamping part, comprising: a blank feeding step of feeding a blank into a heating furnace; a heating step of heating the blank in the heating furnace; a transfer step of transferring the heated blank from the heating furnace to a press; a forming step of forming the transferred blank using the press; and a cooling step of cooling the transferred blank; wherein the heating step involves heating the blank in the heating furnace such that a first peak, which represents a change in the rate of increase of the heating of the blank from the point where the maximum value of the rate of increase of the blank appears after the blank is heated until the point where the rate of increase of the blank becomes zero, and a second peak, which represents a change in the rate of increase of the heating of the blank from the point where the rate of increase of the blank becomes zero until the heating step ends after the point where the maximum value of the rate of increase of the blank appears again.

Inventors

  • 윤승채
  • 박재명
  • 박계정
  • 공제열

Assignees

  • 현대제철 주식회사

Dates

Publication Date
20260507
Application Date
20241030

Claims (8)

  1. Blank feeding step of feeding the blank into the heating furnace; A heating step of heating the above blank in the above heating furnace; A transfer step of transferring the heated blank from the heating furnace to a press; A forming step of forming the conveyed blank using the press; and A cooling step for cooling the transferred blank; Includes, A method for manufacturing a hot stamping part, wherein the heating step involves heating the blank in the heating furnace such that a first peak, representing a change in heating rate from the time the blank starts heating until the time the maximum value of the heating rate of the blank appears, and a second peak, representing a change in heating rate from the time the heating rate of the blank becomes zero, through the time the maximum value of the heating rate of the blank appears again, and until the heating step ends.
  2. In paragraph 1, When the point at which the heating rate of the blank becomes zero is defined as the boundary point between the first peak and the second peak, A method for manufacturing a hot stamping part, wherein the heating step involves heating the blank such that the boundary point between the first peak and the second peak occurs at a time when the time is 40 seconds or more and 70 seconds or less after the blank is heated.
  3. In paragraph 1, A method for manufacturing a hot stamping part, wherein the heating step involves heating the blank such that the ratio of the area of the first peak to the area of the second peak is 1.0 or more and 8.4 or less.
  4. In paragraph 1, A method for manufacturing a hot stamping part, wherein the base material of the blank comprises carbon (C) 0.25 wt% or more and 0.5 wt% or less, silicon (Si) 0.1 wt% or more and 0.8 wt% or less, manganese (Mn) 0.3 wt% or more and 3.0 wt% or less, phosphorus (P) greater than 0 and 0.05 wt% or less, sulfur (S) greater than 0 and 0.01 wt% or less, aluminum (Al) 0.01 wt% or more and 0.05 wt% or less, boron (B) 0.0005 wt% or more and 0.005 wt% or less, chromium (Cr) 0.01 wt% or more and 1.0 wt% or less, molybdenum (Mo) 0.01 wt% or more and 1.0 wt% or less, nickel (Ni) 0.001 wt% or more and 1.0 wt% or less, and the remainder being iron (Fe) and other unavoidable impurities.
  5. A base material; a decarburized layer on the surface of the base material; and a plating layer formed on the base material, comprising The above base material comprises carbon (C) 0.25 wt% or more and 0.5 wt% or less, silicon (Si) 0.1 wt% or more and 0.8 wt% or less, manganese (Mn) 0.3 wt% or more and 3.0 wt% or less, phosphorus (P) greater than 0 and 0.05 wt% or less, sulfur (S) greater than 0 and 0.01 wt% or less, aluminum (Al) 0.01 wt% or more and 0.05 wt% or less, boron (B) 0.0005 wt% or more and 0.005 wt% or less, chromium (Cr) 0.01 wt% or more and 1.0 wt% or less, molybdenum (Mo) 0.01 wt% or more and 1.0 wt% or less, nickel (Ni) 0.001 wt% or more and 1.0 wt% or less, and the remainder being iron (Fe) and other unavoidable impurities. The above plating layer comprises iron (Fe) in an amount of 10 wt% or more and 70 wt% or less, silicon (Si) in an amount of more than 0 wt% and less than or equal to 5 wt%, manganese (Mn) in an amount of more than 0 wt% and less than or equal to 5 wt%, aluminum (Al) in an amount of more than 0 wt% and less than or equal to 5 wt%, and the remainder being zinc (Zn) and other unavoidable impurities. A hot stamping part having a thickness of the above decarburization layer of 8 μm or more and 13 μm or less.
  6. In paragraph 5, A hot stamping part having a tensile strength of 1650 MPa or more.
  7. In paragraph 5, A hot stamping part having a bending angle of 40 degrees or more.
  8. In paragraph 5, A hot stamping part having an average austenite crystal size (AGS) of 30 μm or less.

Description

Hot stamping component and method of manufacturing the same The present invention relates to a hot stamping part having high strength and excellent bendability by securing a decarburized layer, and a method for manufacturing the same. With the tightening of environmental regulations and safety standards in the automotive industry, there is a growing need for lightweight vehicle materials that are also high-strength. Hot stamping technology is attracting attention as a manufacturing method for such high-strength and lightweight vehicle materials, and active research and development on hot stamping materials is underway. The hot stamping process generally consists of heating, forming, cooling, and trimming, and can utilize microstructural changes such as phase transformation of the material and alloying of the plating during the process. In particular, to secure high strength, the material is heated to a high temperature to undergo austenite transformation, and then rapidly cooled in a mold to secure a martensite structure. When applying galvanized zinc plating (GA plating, Galva-annealed plating) to prevent surface oxidation during heating at high temperatures, failure to properly control the furnace temperature and heating time can lead to deterioration in bendability and, if strength decreases, fatal problems such as the occurrence of microcracks. In addition, the characteristics of the decarburized layer on the surface obtained from GA hot stamping cold-rolled material also change depending on the temperature of the furnace and the heating time. Therefore, when heated at high temperatures, a problem occurred in which the decarburized layer decreased excessively, strength was reduced, and flexibility was decreased. FIG. 1 is a flowchart schematically illustrating a method for manufacturing a hot stamping part according to one embodiment of the present invention. FIG. 2 is a graph showing the heating rate (°C/s) of a blank in a heating step according to one embodiment of the present invention. FIG. 3 is a cross-sectional view of a hot stamping part according to one embodiment of the present invention. FIG. 4 is a cross-sectional view of a hot stamping part according to one comparative example of the present invention. FIG. 5 is a cross-sectional view of a hot stamping part according to one embodiment of the present invention. FIG. 6 is a cross-sectional view of a hot stamping part according to one comparative example of the present invention. The present invention will be described in detail below. However, in describing the present invention, if it is determined that a detailed description of related known technologies or configurations may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component. In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise. In the following embodiments, when various components such as layers, films, regions, and plates are described as being "on" another component, this includes not only cases where they are "directly on" another component, but also cases where another component is interposed between them. In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and therefore the present invention is not necessarily limited to what is illustrated. In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added. In this specification, "A and/or B" indicates the case where it is A, B, or both A and B. Additionally, in this specification, "at least one of A and B" indicates the case where it is A, B, or both A and B. Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined. Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. FIG. 1 is a flowchart schematically illustrating a method for manufacturing a hot stamping part according to one embodiment of the prese