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

Manufacturing method of cold-rolled steel sheet, cold-rolled steel sheet, and automobile component

A technology of cold-rolled steel sheets and manufacturing methods, applied in the field of cold-rolled steel sheets, can solve the problems of inability to obtain high-strength cold-rolled steel sheets with corrosion resistance, corrosion resistance, and improved corrosion resistance, and achieve excellent chemical conversion treatment , Excellent corrosion resistance after painting, improved chemical conversion treatment and corrosion resistance after painting

Active Publication Date: 2016-06-01
JFE STEEL CORP
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] However, for the high-strength cold-rolled steel sheet described in Patent Document 1, even if the Si concentration on the surface of the steel sheet is reduced before cold rolling, since Si-containing oxides are formed on the surface of the steel sheet by annealing after cold rolling, it cannot be expected Corrosion resistance will be improved after painting
In addition, for the high-strength cold-rolled steel sheet described in Patent Document 2, although the corrosion resistance does not pose a problem in a corrosive environment such as the salt spray test specified in JISZ2371, the salt-warm water immersion test and the combined cycle corrosion test In such a harsh corrosive environment, sufficient corrosion resistance after painting cannot be obtained
That is, high-strength cold-rolled steel sheets excellent in corrosion resistance after coating cannot be obtained only by reducing the Si concentration on the surface of the hot-rolled steel sheet or by reducing the linear oxides containing Si.

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
  • Manufacturing method of cold-rolled steel sheet, cold-rolled steel sheet, and automobile component
  • Manufacturing method of cold-rolled steel sheet, cold-rolled steel sheet, and automobile component
  • Manufacturing method of cold-rolled steel sheet, cold-rolled steel sheet, and automobile component

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0093]Steel containing C: 0.125% by mass, Si: 1.5% by mass, Mn: 2.6% by mass, P: 0.019% by mass, S: 0.008% by mass, and Al: 0.040% by mass with the balance consisting of Fe and unavoidable impurities Steel raw material (steel billet) is produced by melting and continuous casting through ordinary refining processes such as a converter and degassing treatment. Next, after reheating the billet to a temperature of 1150-1170°C, hot rolling is performed with the finishing temperature set at 850-880°C, and coiled at a temperature of 500-550°C to form a plate Hot-rolled steel plate with a thickness of 3~4mm. Next, these hot-rolled steel sheets are pickled to remove scale, and then cold-rolled to produce cold-rolled steel sheets with a thickness of 1.8mm. Then, these cold-rolled steel sheets are heated to a soaking temperature of 750~780°C and kept After 40 to 50 seconds, perform continuous annealing at 20 to 30°C / second from the above soaking temperature to the cooling stop temperatu...

Embodiment 2

[0120] The steels A to Z having the composition shown in Table 3 were smelted and continuously cast through a common refining process such as a converter and degassing treatment to form a billet. These billets were hot-rolled under the hot-rolling conditions shown in Table 4 to produce hot-rolled steel sheets with a thickness of 3 to 4 mm, pickled to remove scale on the surface of the steel sheets, and then cold-rolled to obtain sheet thicknesses of 3 to 4 mm. 1.8mm cold-rolled steel plate. Next, these cold-rolled steel sheets were continuously annealed under the conditions shown in Table 4, then pickled under the conditions shown in Table 5, then pickled again, washed with water and dried, and subjected to elongation of 0.7%. Skin pass rolling to obtain No. 1~39 cold-rolled steel sheets.

[0121]

[0122]

[0123]

[0124]

[0125]

[0126] Test pieces were cut out from the above-mentioned cold-rolled steel sheets obtained in this way, and the surface coverage...

Embodiment 3

[0133]Steel containing C: 0.125% by mass, Si: 1.5% by mass, Mn: 2.6% by mass, P: 0.019% by mass, S: 0.008% by mass, and Al: 0.040% by mass with the balance consisting of Fe and unavoidable impurities Smelting and continuous casting are carried out to produce steel raw materials (billets). After reheating the slab to a temperature of 1150-1170°C, hot rolling is performed with the finish rolling temperature set at 850-880°C, and coiling is performed at a temperature of 500-550°C to produce a plate with a thickness of 3~ 4mm hot rolled steel plate. These hot-rolled steel sheets were pickled to remove scale, and then cold-rolled to obtain cold-rolled steel sheets with a thickness of 1.8 mm. Next, these cold-rolled steel sheets are heated to a soaking temperature of 750 to 780° C., held for 40 to 50 seconds, and then cooled from the above soaking temperature to a cooling stop temperature of 350 to 400° C. at a rate of 20 to 30° C. / second. Keep the continuous annealing for 100 to ...

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
thicknessaaaaaaaaaa
tensile strengthaaaaaaaaaa
elongationaaaaaaaaaa
Login to View More

Abstract

The present invention provides a method for producing a cold-rolled steel sheet, a cold-rolled steel sheet produced by the method, and an automobile member using the steel sheet. In the production method, it is preferable to carry out continuous rolling after cold-rolling containing 0.5 to 3.0% by mass of Si. The annealed cold-rolled steel sheet is pickled to remove the Si-containing oxide layer on the surface of the steel sheet, and then further pickled so that the surface coverage of the iron-based oxides on the surface of the steel sheet is 40% or less, more preferably the iron-based oxides The maximum thickness of the material is 150nm or less, thereby obtaining a cold-rolled steel sheet that is excellent in chemical conversion treatability and excellent in corrosion resistance after coating in severe corrosion environments such as salt-temperature water immersion test and combined cycle corrosion test.

Description

technical field [0001] The present invention relates to a method for manufacturing cold-rolled steel sheets, cold-rolled steel sheets, and automotive components. Specifically, the present invention relates to excellent chemical conversion treatability and excellent post-paint corrosion resistance as evaluated by a salt-warm water immersion test and a combined cycle corrosion test. A method for manufacturing a cold-rolled steel sheet, a cold-rolled steel sheet manufactured by the method, and an automobile component using the cold-rolled steel sheet. It should be noted that the cold-rolled steel sheet of the present invention can be suitably used as a high-strength cold-rolled steel sheet containing Si and having a tensile strength TS of 590 MPa or more. Background technique [0002] In recent years, there has been an urgent need to improve the fuel efficiency of automobiles from the viewpoint of protecting the global environment. In addition, from the viewpoint of ensuring t...

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 Patents(China)
IPC IPC(8): C23G1/08B21B3/02C21D9/46C22C38/00C22C38/02C22C38/58
CPCB21B3/02C21D8/0236C21D8/0278C23G1/00C23G1/081C23G1/085C23G1/086C23G1/088C22C38/02C22C38/04C22C38/001C22C38/002C22C38/005C22C38/06C22C38/08C22C38/12C22C38/14C22C38/16C22C38/22C22C38/32C22C38/34C22C38/38Y10T428/26C22C38/00C23G1/08C21D9/46B21B45/0269
Inventor 增冈弘之安藤聪山本俊佑
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