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

High-strength steel plate and method for producing same

A technology of high-strength steel plates and manufacturing methods, applied in the direction of manufacturing tools, chemical instruments and methods, and improvement of process efficiency, can solve problems such as deterioration of resistance to delayed fracture, delayed fracture, etc.

Active Publication Date: 2021-04-09
JFE STEEL CORP
View PDF10 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When a steel plate with a tensile strength of 980 MPa or higher is formed by press forming, delayed fracture may occur due to an increase in residual stress in the part or deterioration of the delayed fracture resistance of the steel plate itself.

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
  • High-strength steel plate and method for producing same
  • High-strength steel plate and method for producing same
  • High-strength steel plate and method for producing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0186] Steel ingots were melted and cast under the conditions shown in Table 2 using steels having the composition shown in Table 1. The obtained steel ingots were hot-rolled under the conditions shown in Table 2 to obtain hot-rolled steel sheets with a thickness of 2.8 mm. In addition, the coiling temperature of hot rolling was performed at 550 degreeC. Next, cold rolling at a cold rolling ratio of 50% was performed to have a plate thickness of 1.4 mm, and treatments under the annealing conditions shown in Table 2 were implemented. After annealing, temper rolling with an elongation of 0.2% was performed. It should be noted that the casting temperatures in Table 2 were obtained by actually measuring the molten steel temperature in the tundish. In addition, the solidification temperature is calculated|required from the following formula by actually measuring the component composition of steel.

[0187] Solidification temperature (°C)=1539-(70×[%C]+8×[%Si]+5×[%Mn]+30×[%P]+25×...

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
hardnessaaaaaaaaaa
tensile strengthaaaaaaaaaa
Login to View More

Abstract

The present invention addresses the problem of providing: a high-strength steel plate having excellent delayed fracture resistance and a tensile strength of at least 980 MPa; and a method for producing same. This high-strength steel plate has a specific composition, wherein the degree of Mn segregation in a specific region is 1.5 or less, the maximum concentration of P in a specific region is 0.08 mass% or less, specific MnS particles are included in a cross section parallel to the rolling direction of the steel plate in a region within 100 [mu]m from the surface of the plate in the thickness direction, the number of the specific MnS particles is 2.0 or less per 1 mm<2>, the number of specific oxide inclusions is 8 or less per 1 mm<2>, at least 80% by number of the oxide inclusions have a specific composition, the microstructure of the steel comprises 30-95% of martensite, 5-70% of ferrite phase, less than 30% (including 0%) of bainite, and less than 2.0% (including 0%) of austenite phase by volume percentage, and the tensile strength is at least 980 MPa.

Description

technical field [0001] The present invention relates to a high-strength steel sheet that is excellent in delayed fracture resistance and is suitable for use as a material for automobile parts and the like, and to a method for producing the same. Background technique [0002] In recent years, with the increasing awareness of the protection of the earth's environment, it is urgent to improve fuel consumption to reduce CO 2 emissions. As a result, there has been a growing trend to increase the strength of steel sheets used as raw materials for automobile parts, to achieve thinner parts, and to reduce the weight of vehicle bodies. When a steel sheet with a tensile strength of 980 MPa or higher is formed by press forming, delayed fracture may occur due to an increase in residual stress in the part or deterioration of the delayed fracture resistance of the steel sheet itself. Here, delayed fracture means that when a component is placed in a hydrogen intrusion environment under a...

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): C22C38/00B22D11/00B22D11/11B22D11/12C21C7/10C21D9/46C22C38/06C22C38/60C23C2/06B22D11/115
CPCC21D9/46C22C38/06C22C38/60C23C2/06C22C38/04C22C38/02C22C38/38C22C38/58C22C38/002C22C38/14C22C38/28C22C38/50C22C38/12C22C38/26C22C38/24C22C38/46C22C38/22C22C38/44C22C38/32C22C38/54C22C38/16C22C38/20C22C38/42C22C38/005C22C38/008B22D11/182B22D11/16C21D8/021C21D8/0226C21D8/0236C21D8/0273C21D8/0263C21D1/19C21D1/25C21D1/26C21D2211/004C21D2211/005C21D2211/008C21D2211/002C21D2211/001B32B15/013C23C2/024C23C2/02C23C2/0224C22C38/001C21C7/10B22D11/115B22D11/12C21D6/005C21D6/008C21D8/0205C21D8/0247C22C38/08C22C38/48C23C2/40
Inventor 小野义彦本田佑马吉冈真平谷口公一松田广志村井刚中村展之
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