High-strength steel sheet having excellent processability and low-temperature toughness, and method for producing same

A high-strength steel plate, low-temperature toughness technology, applied in chemical instruments and methods, manufacturing tools, hot-dip plating processes, etc., can solve problems such as poor low-temperature toughness and no consideration of low-temperature toughness

Inactive Publication Date: 2016-05-11
KOBE STEEL LTD
View PDF11 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In addition to improving the above characteristics, high-strength steel sheets are expected to improve low-temperature toughness in order to improve crash safety at low ...

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 sheet having excellent processability and low-temperature toughness, and method for producing same
  • High-strength steel sheet having excellent processability and low-temperature toughness, and method for producing same
  • High-strength steel sheet having excellent processability and low-temperature toughness, and method for producing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0235] Below, the present invention is described in more detail by enumerating the examples, but the present invention is not limited by the following examples, and of course it can also be implemented by adding appropriate changes within the scope of the above and the following contents, and these are also included in this document. within the technical scope of the invention.

[0236] Steels with the chemical composition shown in Table 1 below (with the balance being iron and inevitable impurities other than P, S, N, and O) were subjected to vacuum melting to manufacture experimental slabs. In Table 1 below, the REM uses misch metal containing about 50% of La and about 30% of Ce.

[0237] Ac was calculated based on the chemical composition shown in Table 1 below and the above formula (a). 3 The Ms point was calculated based on the chemical components shown in Table 1 below and the above formula (b). It should be noted that for No. D-3, the reverse transformation did not pr...

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

A high-strength steel sheet according to the present invention satisfies a predetermined chemical composition, wherein the metal structure of the steel sheet is composed of a polygonal ferrite, a bainite formed in a high temperature range, a bainite formed in a low temperature range and a retained austenite each having a predetermined area ratio, and the distribution of specific crystal grains as determined by an electron backscatter diffraction method employing an average IQ value for each of the crystal grains satisfies formulae (1) and (2) shown below. According to the present invention, it becomes possible to provide a high-strength steel sheet that can exhibit excellent processability and low-temperature toughness even at tensile strength of 590 MPa or more. (1) (IQave-IQmin)/(IQmax-IQmin) >= 0.40; (2) [sigma]IQ/(IQmax-IQmin) <= 0.25

Description

technical field [0001] The present invention relates to a high-strength steel sheet having a tensile strength of 590 MPa or more and excellent workability and low-temperature toughness, and a method for producing the same. Background technique [0002] In the automotive industry, CO 2 Countermeasures against global environmental problems, such as emission restrictions, are urgently needed. On the other hand, from the viewpoint of ensuring the safety of passengers, collision safety standards for automobiles are being strengthened, and structural designs that can sufficiently ensure safety in the passenger space are being carried out. In order to meet these requirements at the same time, it is effective to use high-strength steel sheets with a tensile strength of 590 MPa or more as structural members of automobiles, and further reduce the thickness of the steel sheets to reduce the weight of the vehicle body. However, in general, if the strength of a steel sheet is increased...

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): C22C38/00C21D9/46C22C38/60
CPCC22C38/00C22C38/60C21D8/0236C21D8/0247C21D8/0284C21D9/573C21D1/20C21D1/22C21D2201/05C21D2211/001C21D2211/002C21D2211/005C21D2211/008C21D9/46B32B15/013C21D1/19C21D6/004C21D6/005C21D6/008C22C38/001C22C38/002C22C38/005C22C38/02C22C38/04C22C38/06C22C38/08C22C38/12C22C38/14C22C38/16C22C38/34C22C38/38C23C2/285C23C2/06C23C2/36C25D3/22
Inventor 村田忠夫粕谷康二水田纱江二村裕一
Owner KOBE STEEL LTD
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