High-strength cold-rolled steel sheet and manufacturing method therefor

A cold-rolled steel plate, high-strength technology, applied in the direction of manufacturing tools, chemical instruments and methods, metal material coating technology, etc., can solve problems such as difficult to obtain high strength

Active Publication Date: 2020-10-30
NIPPON STEEL CORP
View PDF15 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, it is difficult to obtain high strength above 1310MPa

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 cold-rolled steel sheet and manufacturing method therefor
  • High-strength cold-rolled steel sheet and manufacturing method therefor
  • High-strength cold-rolled steel sheet and manufacturing method therefor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0161] The present invention will be described more specifically with reference to examples. Slabs having the chemical compositions shown in Table 1 were cast. The cast slab is heated to 1100°C or higher, hot-rolled to 2.8 mm so that the exit temperature of the finish rolling is equal to or higher than the Ar3 transformation point, coiled at 500°C to 650°C, and cooled to room temperature.

[0162] Thereafter, the scale was removed by pickling, and after cold rolling to 1.4 mm, annealing was performed for 120 seconds at the soaking temperature shown in Table 2A. For annealing, the furnace atmosphere during heating and soaking is set to a nitrogen-hydrogen mixed atmosphere having a dew point of -20°C to 20°C and containing hydrogen and nitrogen in an amount of 1.0% by volume to 20% by volume. The heating rate from 700° C. to the soaking temperature during heating for annealing is set to be less than 5.0° C. / s.

[0163] After annealing, it was cooled to the temperature shown in...

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
particle sizeaaaaaaaaaa
tensile strengthaaaaaaaaaa
elongationaaaaaaaaaa
Login to view more

Abstract

A high-strength cold-rolled steel sheet having a prescribed chemical composition, wherein the structure at a position 1 / 4 of the sheet thickness from the surface is, by volume ratio, 70.0% or more tempered martensite, more than 3.0% but less than 10.0% residual austenite, a total of 25.0% or less of ferrite and bainite, and 5.0% or less of martensite, the structure at a position 25 mum from the surface is, by volume ratio, a total of 70% or more of ferrite and bainite and a total of 30% or less of martensite and tempered martensite, and at the position 25 mum from the surface the average graindiameter of the martensite and the tempered martensite is 5.0 mum or less, the tensile strength is 1310 MPa or greater, the uniform elongation is 5.0% or greater, and the ratio R / t of the 90-degree V-bend limit bend radius R and the thickness t is 5.0 or less.

Description

technical field [0001] The invention relates to a high-strength cold-rolled steel plate and a manufacturing method thereof. [0002] This application claims priority based on Japanese Patent Application No. 2018-051020 for which it applied in Japan on March 19, 2018, and uses the content here. Background technique [0003] In today's highly specialized industrial technology field, special and high performance is required for materials used in each technical field. Especially with regard to steel sheets for automobiles, the demand for thin-walled high-strength steel sheets with high formability is remarkably increasing in order to reduce the weight of automobile bodies and improve fuel efficiency in consideration of the global environment. For steel sheets for automobiles, especially cold-rolled steel sheets (including coated steel sheets such as hot-dip galvanized steel sheets and alloyed hot-dip galvanized steel sheets) used in automotive steel sheets, not only high streng...

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): C22C38/00C21D9/46C22C38/38
CPCC22C38/38C21D9/46C22C38/001C22C38/002C22C38/02C22C38/04C22C38/06C22C38/14C22C38/22C21D2211/001C21D2211/002C21D2211/005C21D2211/008C21D8/0205C21D8/0226C21D8/0236C21D8/0273C21D6/005C21D6/008C23C2/40C21D1/76C21D1/19C21D1/22C23C2/28C22C38/32C22C38/24C21D8/0247C23C2/06B32B15/013C21D6/002Y10T428/12958Y10T428/12951B32B15/043C23C30/00C23C28/025B32B15/18C23C30/005Y10T428/12799B32B15/04C23C28/3225Y10T428/12972C22C38/18C22C38/48C22C38/26C22C38/28C22C38/44C22C38/54C22C38/50C22C38/12C22C38/46
Inventor 西尾拓也秋叶浩二郎成田欣正大野功太郎加藤敏东昌史
Owner NIPPON 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