High-strength steel plate having excellent formability, toughness and weldability, and production method of same

A high-strength steel plate and manufacturing method technology, applied in the direction of manufacturing tools, metal rolling, furnaces, etc., can solve the problems of reduced formability and difficulty in processing, and achieve the effect of excellent toughness and weldability

Active Publication Date: 2021-07-23
NIPPON STEEL CORP
View PDF20 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in general, if the strength of the steel plate is increased, the formability (ductility, hole expandability, etc.) will decrease, and it will become difficult to process into complicated shapes. Therefore, strength and formability (ductility, hole expandability, etc.) The balance of the two is not simple, so far, various techniques have been proposed

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 having excellent formability, toughness and weldability, and production method of same
  • High-strength steel plate having excellent formability, toughness and weldability, and production method of same
  • High-strength steel plate having excellent formability, toughness and weldability, and production method of same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0543] (Example 1: Manufacture of steel plate for heat treatment)

[0544] Molten steels having the composition shown in Table 1 and Table 2 were cast to produce steel slabs. Next, the billets were hot-rolled under the conditions shown in Tables 3 to 4.

[0545] Table 1

[0546]

[0547] ※Underlined items are outside the scope of the present invention.

[0548] Table 2

[0549]

[0550] ※Underlined items are outside the scope of the present invention.

[0551] table 3

[0552]

[0553] ※Underlined items are outside the scope of the present invention.

[0554] Table 4

[0555]

[0556] ※Underlined items are outside the scope of the present invention.

[0557] The hot-rolled steel sheets were further processed under the conditions shown in Tables 5 to 9 to obtain heat-treated steel sheets.

[0558] The examples described as "manufacturing method A" in Tables 5 to 9 are examples manufactured by the manufacturing method a1 (without performing intermediate heat ...

Embodiment 2

[0571] (Example 2: Manufacture of high-strength steel plate)

[0572] By subjecting the steel sheets for heat treatment shown in Tables 10 to 14 to heat treatment (final heat treatment) under the conditions shown in Tables 15 to 20, high-strength steel sheets excellent in formability, toughness, and weldability can be obtained.

[0573]

[0574]

[0575]

[0576]

[0577]

[0578]

[0579] Some steel sheets for heat treatment were subjected to plating treatment under the conditions shown in Table 21 in addition to the heat treatments shown in Tables 15 to 20. It should be noted that in Table 21, GA refers to an alloyed hot-dip galvanized steel sheet, GI refers to a non-alloyed hot-dip galvanized steel sheet, and EG refers to an electroplated steel sheet.

[0580] Table 21

[0581]

[0582] ※Underlined items are outside the scope of the present invention.

[0583] Tables 22 to 27 show the microstructures of the obtained high-strength steel sheets and the ...

experiment example 2

[0609] Experimental example 2 is an example in which the temperature change process during the heating process does not satisfy the formula (3) when the steel plate 1a for heat treatment is heat treated, and the steel plate that has a large amount of coarse and massive martensite and does not satisfy the formula (A) has a toughness become inferior.

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
diameteraaaaaaaaaa
tensile strengthaaaaaaaaaa
particle sizeaaaaaaaaaa
Login to view more

Abstract

The invention provides a high-strength steel plate which has excellent formability, toughness and weldability, and is characterized in that the component composition has, in mass%, C: 0.05-0.30%, Si: 2.50% or less, Mn: 0.50-3.50%, P: 0.100% or less, S: 0.0100% or less, Al: 0.001-2.500%, N: 0.0150% or less, and O: 0.0050% or less, the remainder being Fe and unavoidable impurities, wherein the microstructure of the region from 1 / 8t (t: plate thickness) to 3 / 8t (t: plate thickness) from the surface of the steel plate contains, in vol%, at least 20% acicular ferrite and at least 10% martensite (4), and is limited to no more than 20% globular ferrite and no more than 2.0% retained austenite, and the martensite satisfies expression (A).

Description

technical field [0001] The present invention relates to a high-strength steel sheet excellent in formability, toughness, and weldability, and a method for producing the same. Background technique [0002] In recent years, in automobiles, high-strength steel sheets are widely used in order to reduce the weight of the vehicle body to improve fuel efficiency and reduce carbon dioxide emissions, and to absorb collision energy in the event of a collision to ensure the protection and safety of passengers. However, in general, if the strength of the steel plate is increased, the formability (ductility, hole expandability, etc.) will decrease, and it will become difficult to process into complicated shapes. Therefore, strength and formability (ductility, hole expandability, etc.) The balance is not simple, and various techniques have been proposed so far. [0003] For example, Patent Document 1 discloses a technology in which, in a high-strength steel sheet having a tensile strengt...

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): C22C38/00B21B3/00C21D9/46C22C38/06C22C38/60C25D5/26C25D5/50
CPCC21D9/46C22C38/06C22C38/02C22C38/04C22C38/12C22C38/14C22C38/26C22C38/28C22C38/16C22C38/08C22C38/38C22C38/22C22C38/32C22C38/002C22C38/005C25D5/50C23C2/06C23C2/02C23C30/00C21D8/021C21D8/0226C21D8/0263C21D8/0268C21D8/0236C21D1/19C21D8/0273C21D8/0426C21D8/0436C21D8/0463C21D8/0468C21D8/0473C21D9/48C21D2211/008C21D2211/002C21D2211/005C21D2211/001C21D1/185C21D1/25C21D1/26C22C38/60C23C2/0224C22C38/001C22C38/58C22C38/42C22C38/54C22C38/44B21B3/00B21C47/02C21D8/0205C22C38/46C22C38/48C22C38/50C23C2/40
Inventor 川田裕之樱田荣作佐野幸一横山卓史
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