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CN-116855870-B - Cladding hot stamping steel part and preparation method thereof

CN116855870BCN 116855870 BCN116855870 BCN 116855870BCN-116855870-B

Abstract

The application relates to the technical fields of preparation and stamping forming manufacturing of hot stamping steel with a coating, in particular to a hot stamping steel part with a coating and a preparation method thereof. The method comprises the steps of setting a single heat-preserving step to carry out first-mode austenitizing heat treatment on a first plate to obtain a first austenitizing plate, obtaining the ratio of the thickness of an interdiffusion layer in the first austenitizing plate to the thickness of a surface alloy layer, judging whether to carry out different-mode austenitizing heat treatment on a plurality of plates in a mode of increasing the number of the heat-preserving steps one by one according to the ratio, and carrying out n-th-mode austenitizing heat treatment on the n-th plate when the n-th heat-preserving step is set, so that the ratio of the thickness of the interdiffusion layer in the n-th plate to the thickness of the surface alloy layer reaches a preset ratio, and then stamping and maintaining pressure to obtain a plated hot stamped steel part. The application solves the technical problem that the existing coating hot stamping steel is easy to cause coating sticking roll phenomenon in the heating process.

Inventors

  • LIU XINGQUAN
  • ZHANG LIANG
  • MA WENYU
  • HUANG XUEQI
  • LIN XINGMING
  • XIE PENG
  • MA YAOFENG
  • XU QILIANG

Assignees

  • 北京首钢股份有限公司

Dates

Publication Date
20260508
Application Date
20230720

Claims (8)

  1. 1. A method of producing a coated hot stamped steel part, the method comprising: Setting a single heat-insulating step to perform first-mode austenitizing heat treatment on the first plate to obtain a first austenitized plate; Sampling and detecting the first austenitized sheet material to obtain the ratio of the thickness of the interdiffusion layer in the first austenitized sheet material to the thickness of the surface alloy layer; judging whether the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the first austenitizing plate is more than 0.1; If the ratio is not greater than 0.1, carrying out austenitizing heat treatment on a plurality of plates in different modes in a mode of increasing the number of heat preservation steps one by one, sampling and detecting the heat treated plates after increasing the number of heat preservation steps each time to obtain the ratio of the thickness of an interdiffusion layer to the thickness of a surface alloy layer, and taking the nth plate as a target austenitizing plate after detecting that the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the nth plate is greater than 0.1 after setting the nth heat preservation step to carry out the nth mode austenitizing heat treatment on the nth plate; if the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the first austenitizing plate is greater than 0.1, the first austenitizing plate is taken as a target austenitizing plate; and stamping and maintaining the pressure of the target austenitized sheet to obtain the hot stamping steel part of the coating.
  2. 2. The method of claim 1, wherein the end point soak temperature in the n-mode austenitizing heat treatment is >840 ℃.
  3. 3. The method of claim 1, wherein the n-th mode austenitizing heat treatment time is <12 minutes.
  4. 4. The method of claim 1, wherein the end point soak temperature in the n-th mode austenitizing heat treatment is 933 ℃, the time of the n-th mode austenitizing heat treatment is 4 minutes, and the ratio of inter-diffusion layer thickness to surface alloy layer thickness in the target austenitized sheet material is >0.2.
  5. 5. The method of claim 1, wherein the energy absorbed by the sheet material is equal in each of said modes of austenitizing heat treatment.
  6. 6. The method of claim 1, wherein the stamping die temperature is <100 ℃.
  7. 7. The method of claim 1, wherein the stamping and maintaining the target austenitized sheet to obtain a plated hot stamped steel part comprises: And stamping and maintaining the pressure of the target austenitized sheet, and controlling the cooling speed of the target austenitized sheet to obtain a coated hot stamping steel part, wherein the cooling speed is more than 27 ℃ per second.
  8. 8. A coated hot stamped steel part, characterized in that it is produced by the method according to any one of claims 1-7.

Description

Cladding hot stamping steel part and preparation method thereof Technical Field The application relates to the technical fields of preparation and stamping forming manufacturing of hot stamping steel with a coating, in particular to a hot stamping steel part with a coating and a preparation method thereof. Background Automobile weight reduction is a major trend of current times development, so the hot stamping technology is widely used. In the hot stamping process, it is necessary to heat the hot-formed steel sheet to a temperature higher than the austenitizing temperature and then stamp it. Because the bare board is easy to cause serious oxide scale during stamping, the shape accuracy of the part can be affected by subsequent shot blasting. Thus, a hot stamped steel with a coating is proposed. Hot stamped steel with a coating layer, however, is prone to cause sticking of the coating layer during heating. The adhesive roller influences the service life of the heating furnace roller, and simultaneously influences the coating quality of the steel plate, thereby causing adverse effects on subsequent use. There is therefore a need for new methods for reducing the sticking phenomenon. Disclosure of Invention The application provides a coating hot stamping steel part and a preparation method thereof, which are used for solving the technical problem that the coating hot stamping steel is easy to cause coating sticking roll phenomenon in the heating process. In a first aspect, the present application provides a method for producing a coated hot stamped steel part, the method comprising: Setting a single heat-insulating step to perform first-mode austenitizing heat treatment on the first plate to obtain a first austenitized plate; Sampling and detecting the first austenitized sheet material to obtain the ratio of the thickness of the interdiffusion layer in the first austenitized sheet material to the thickness of the surface alloy layer; According to the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the first austenitizing plate, carrying out austenitizing heat treatment in different modes on a plurality of plates in a mode of judging whether to increase the number of heat preservation steps one by one or not until the nth plate is subjected to the nth mode austenitizing heat treatment when the nth heat preservation step is arranged, so that the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the nth plate reaches a preset ratio, and obtaining a target austenitizing plate; and stamping and maintaining the pressure of the target austenitized sheet to obtain the hot stamping steel part of the coating. Optionally, according to the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the first austenitizing slab, determining whether to perform austenitizing heat treatment in different modes on the plurality of slabs in a mode of increasing the number of heat preservation steps one by one until the nth slab is subjected to the nth mode austenitizing heat treatment when the nth heat preservation step is set, so that the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the nth slab reaches a preset ratio, and obtaining the target austenitizing slab, including: if the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the first austenitizing plate is less than or equal to 0.1, carrying out austenitizing heat treatment in different modes on a plurality of plates in a mode of increasing the number of heat preservation steps one by one until the nth plate is subjected to the nth mode austenitizing heat treatment when the nth heat preservation step is arranged, so that the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the nth plate reaches a preset ratio, and obtaining a target austenitizing plate; And if the ratio of the thickness of the interdiffusion layer to the thickness of the surface alloy layer in the first austenitizing plate material is more than 0.1, obtaining the target austenitizing plate material. Optionally, the preset ratio is >0.1. Optionally, the end point holding temperature in the n-mode austenitizing heat treatment is >840 ℃. Optionally, the time of the n-th mode austenitizing heat treatment is <12min. Optionally, the end point heat preservation temperature in the nth mode austenitizing heat treatment is 933 ℃, the time of the nth mode austenitizing heat treatment is 4min, and the ratio of the thickness of the interdiffusion layer in the target austenitizing plate material to the thickness of the surface alloy layer is more than 0.2. Optionally, in each of the modes of austenitizing heat treatment, the energy absorbed by the sheet material is equal. Optionally, the die temperature of the stamping is <100 ℃. Optionall