Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Hot-press member and method for manufacturing same, and cold-rolled steel sheet for hot pressing and method for manufacturing same

A technology of cold-rolled steel plate and manufacturing method, which is applied in the field of hot-pressed components and its manufacture, as well as cold-rolled steel plate for hot-pressing and its manufacture, can solve problems such as liquid metal brittle steel plate cracks, zinc melting, etc., and achieve high tensile strength, Excellent resistance to resistance welding cracking and delayed fracture resistance, excellent resistance to resistance welding cracking

Active Publication Date: 2020-02-14
JFE STEEL CORP
View PDF13 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] However, most automobile assembly processes are assembled by resistance spot welding. In this case, there is a Zn-containing plating layer on the surface of the cold-rolled steel sheet for hot-pressing, even if the cold-rolled steel sheet for hot-pressing However, in the case of assembly by resistance spot welding with a plated steel sheet containing Zn, since the zinc on the surface of the steel sheet is melted during welding and residual stress is generated near the welded part, there is a concern that liquid metal brittleness and cracks in the steel sheet will occur. welding crack

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Hot-press member and method for manufacturing same, and cold-rolled steel sheet for hot pressing and method for manufacturing same
  • Hot-press member and method for manufacturing same, and cold-rolled steel sheet for hot pressing and method for manufacturing same
  • Hot-press member and method for manufacturing same, and cold-rolled steel sheet for hot pressing and method for manufacturing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0176] Hereinafter, examples of the present invention will be described.

[0177] It should be noted that the present invention is not limited to the following examples, and can also be appropriately modified within the scope of the gist of the present invention, and all of them are included in the technical scope of the present invention.

[0178] Steel with the composition shown in Table 1 was melted and cast to form a slab, heated to 1250° C., and then hot-rolled at the finish rolling finish temperature (FDT) as shown in Table 2. Next, the hot-rolled steel sheet was cooled to the coiling temperature (CT) at the first average cooling rate (cooling rate 1) shown in Table 2, and coiled into a coil.

[0179] Next, after pickling the obtained hot-rolled sheet, it cold-rolled by 50% of rolling reduction, and it was set as the cold-rolled sheet (sheet thickness: 1.4 mm).

[0180] Next, the cold-rolled steel sheet obtained in this way is subjected to the first and second annealing...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
tensile strengthaaaaaaaaaa
particle diameteraaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

Provided is a hot-press member that can have very high tensile strength such as TS: 1780 MPa or larger after hot pressing, and excellent crack resistance during resistance welding and delayed fractureresistance after resistance welding, the hot press member being obtained by appropriately adjusting the component composition thereof and making the microstructure thereof such that the average crystal grain size of prior austenite is 7 microns or less, the volume ratio of martensite is 90% or more, the average number of Nb-based precipitate having a grain size of less than 0.08 microns in a 100-micron<2> 2-section parallel with the thickness direction of the member is 5 or more in a region within 100 microns from the surface of the member in the plate thickness direction, and a Ni-diffused region having a thickness of 0.5 microns or more is present in the surface layer of the member.

Description

technical field [0001] The present invention relates to a hot-pressed member and a manufacturing method thereof, a cold-rolled steel sheet for hot-pressing and a manufacturing method thereof, in particular to a hot-pressed member whose resistance to resistance welding cracking and resistance to delayed fracture after resistance welding are improved for a hot-pressed member . [0002] In the present invention, a hot-pressed member refers to a member obtained by hot-press forming a hardenable cold-rolled steel sheet to increase its strength. Background technique [0003] In recent years, due to increasing environmental concerns, CO 2 Emission regulations have become stricter, and weight reduction of vehicle bodies for fuel efficiency improvement has become an issue in the automotive field. For this reason, the application of high-strength steel sheets to automotive parts to achieve thinning is being promoted, and the application of steel sheets with a tensile strength (TS) o...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/00C21D1/18C21D9/00C21D9/46C22C38/14C22C38/60
CPCC21D1/18C22C38/14C22C38/60C21D2211/004C21D2211/008C21D2211/005C22C38/002C22C38/005C22C38/008C22C38/02C22C38/04C22C38/06C22C38/10C22C38/12C22C38/32C21D9/48C21D1/25C21D1/84C21D7/13C21D8/0426C21D8/0436C21D8/0463C21D1/185C25D7/0614C25D5/50C23C2/06C23C2/12C23C2/40C23C2/28C23C10/28B21D22/022B21D22/208B21D53/88B21D35/005B21D22/20C21D9/46C22C38/001C22C38/42C22C38/58C22C38/48C22C38/50B32B15/015C21D6/001C21D6/002C21D6/005C21D6/007C21D6/008C21D8/0205C21D8/0226C21D8/0236C21D8/0263C22C38/08C22C38/16C22C38/26C22C38/28C22C38/38
Inventor 高岛克利泽西央海小林崇船川义正
Owner JFE STEEL CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com