High-strength steel plate and method for manufacturing same

A high-strength steel sheet, a technology for manufacturing methods, applied in manufacturing tools, furnace types, hot-dip plating processes, etc., can solve the problems of reduced ductility and stretch flangeability, and achieve excellent ductility and stretch flangeability, and fuel consumption. The effect of improving and improving collision safety

Active Publication Date: 2018-10-26
JFE STEEL CORP
View PDF4 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, in general, when the strength of the steel plat

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0106] Next, the action and effect of the high-strength steel sheet and its manufacturing method of the present invention will be described using examples.

[0107] Vacuum-melted steel having the composition shown in Table 1 was smelted in a laboratory to produce a thin slab with a thickness of 20 mm. These thin plate slabs were rolled at a heating temperature of 1250°C and a finishing exit temperature of 880°C, cooled to 650°C at a rate of 40°C / sec after rolling, and coiled at 650°C for heat treatment. The hot-rolled sheet thus obtained was pickled with hydrochloric acid and cold-rolled at a reduction ratio of 50% to produce a cold-rolled steel sheet with a thickness of 1.2 mm. Next, it was heat-treated under the heat treatment conditions shown in Table 2 to manufacture out of cold-rolled steel. In addition, this cold-rolled steel plate was used as a starting steel plate.

[0108] In addition, vacuum-melted steel having the composition shown in Table 1 was smelted in a labo...

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

No PUM Login to view more

Abstract

Provided are a high-strength steel plate having superior ductility and stretch flangeability and a method for manufacturing the same. This high-strength steel plate is formed from a prescribed component composition and has C/Mn of 0.08-0.20 with the balance being iron and inevitable impurities. The structure has, in surface area to total structure, a total of 40-70% of ferrite and bainitic ferrite, and 5-35% of martensite, with the remainder austenite being 5-30%, and furthermore, and the proportion of martensite (including the remainder austenite) adjacent to bainitic ferrite being 60% or greater of the total martensite (including the remainder austenite). The proportion of hardness differential for microhardness measured at a measurement interval of 0.5 [mu]m being 4.0 GPa or less is 70%or greater, and the proportion of structure out of the total structure having a microhardness of 8.0 GPa or less is 85% or greater.

Description

technical field [0001] The present invention relates to a high-strength steel sheet having excellent ductility and stretch-flangeability and having a tensile strength (TS) of 980 MPa or more, and a method for producing the high-strength steel sheet, which is suitable for compression molding into complex-shaped automobile parts and the like. Background technique [0002] In recent years, from the perspective of protecting the global environment, fuel consumption of automobiles has been improved, and the weight reduction of automobile bodies has been promoted. In addition, from the viewpoint of ensuring the safety of occupants during a collision, it is also required to improve the collision safety of the automobile body. In view of such demands, the application of high-strength steel sheets with a TS of 980 MPa or more to automobile bodies is expanding. [0003] However, generally, when the strength of a steel sheet is increased, the ductility and stretch-flangeability decrea...

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
IPC IPC(8): C22C38/00C21D8/02C21D9/46C22C38/06C22C38/58
CPCC21D8/02C21D9/46C22C38/00C22C38/06C21D8/0205C23C2/06C23C2/28C22C38/001C22C38/02C22C38/04C22C38/38C21D2211/001C21D2211/002C21D2211/005C21D2211/008C23C2/12C21D8/0247C22C38/002C22C38/005C22C38/08C22C38/12C22C38/14C22C38/16C22C38/22C23C2/024C23C2/02C23C2/0224
Inventor 椎森芳惠金子真次郎长泷康伸
Owner JFE STEEL CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap