1200-MPa-level cold milling steel and manufacturing method thereof

A manufacturing method and finishing rolling technology, applied in 1200MPa grade cold-rolled Q&P steel and its manufacturing field, can solve the problems of difficult to guarantee product surface quality, unfavorable automobile driving safety, and difficult industrial realization, and achieve good resistance to hydrogen-induced cracking and The effect of strong plasticity, inhibition of hydrogen diffusion, and simple process

Inactive Publication Date: 2015-10-21
HEBEI IRON AND STEEL
View PDF9 Cites 32 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the Chinese patent publications whose publication numbers are CN103215516A, CN103805851A, CN103233161A, CN103805869A, CN102226248A, and CN101775470A all disclose the production method of hot-rolled Q&P steel, which is characterized in that the process flow is short and the production cost is low; High requirements are put forward, it is difficult to realiz

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
  • 1200-MPa-level cold milling steel and manufacturing method thereof
  • 1200-MPa-level cold milling steel and manufacturing method thereof
  • 1200-MPa-level cold milling steel and manufacturing method thereof

Examples

Experimental program
Comparison scheme
Effect test

Example

[0025] Example 1-10: This 1200MPa grade cold rolled Q&P steel is manufactured by the following specific process.

[0026] The chemical composition in each embodiment is shown in Table 1, the hot rolling process system is shown in Table 2, the heat treatment process is shown in Table 3, and the mechanical properties of the products of each embodiment are shown in Table 4.

[0027] Table 1: Chemical composition of Q&P steel in each embodiment (H in ppm, other wt%)

[0028]

[0029] In Table 1, the balance of the composition ratio of each example is Fe and unavoidable impurities.

[0030] Table 2: Hot rolling and cold rolling process of each embodiment

[0031]

[0032] Table 3: Heat treatment process of each embodiment

[0033]

[0034] Table 4: Mechanical properties of Q&P steel obtained in each example

[0035]

[0036] It can be seen from Table 4 that the cold-rolled Q&P steel obtained in this example has high tensile strength, good hydrogen-induced cracking resistance and strong plastic...

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

The invention discloses 1200-MPa-level cold milling steel and a manufacturing method thereof. The steel comprises, by mass, 0.15-4.0% of C, 0.3-2.0% of Si, 1.0-5.0% of Mn, S with the amount equal to or smaller than 0.01 ppm, P with the amount equal to or smaller than 0.01 ppm, H with the amount equal to or smaller than 20 ppm, 0.02-2.0% of Al, 0.01-0.04% of Nb, and the balance Fe and unavoidable impurities. As the Nb element is added to the steel, crystal grain can be effectively refined, the area of crystal boundaries is increased to adsorb hydrogen atoms, and then hydrogen spreading is effectively restrained; in addition, a precipitate Nb (C, N) formed by Nb is a hydrogen trap and can effectively adsorb hydrogen in the steel so that hydrogen can be distributed uniformly in the steel and restrained from spreading or gathering, and the hydrogen induced cracking resistant characteristic of the steel is improved; in addition, the Nb element is a stable retained austenite element and can increase the strength and ductility product of the steel; due to microalloying of Nb, the hydrogen induced cracking resistant characteristic of the steel can be effectively improved; meanwhile, the crystal grain can be refined, and the stability of austenite is improved. The steel has the advantages of being high in hydrogen induced cracking resistance, large in strength and ductility product, and capable of effectively improving the driving safety of an automobile.

Description

technical field [0001] The invention relates to a high-strength automobile steel, in particular to a 1200MPa grade cold-rolled Q&P steel and a manufacturing method thereof. Background technique [0002] Q&P steel has excellent tensile strength and elongation. The tensile strength reaches 1200MPa while the elongation reaches more than 14%. It is of great significance to improve safety performance and reduce environmental emissions. Q&P adopts 80-90% volume fraction of martensite strengthening, so it has extremely high tensile strength. At the same time, using the "carbon partition" process and principle, the steel is heated to the austenite zone, and then cooled rapidly, at the quenching temperature and Keep warm at a slightly higher partition temperature to diffuse supersaturated carbon in martensite into austenite without forming or rarely forming carbide precipitation, so that 10-20% volume fraction of stable retained austenite remains to room temperature. During the de...

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): C22C38/12C21D8/00
Inventor 熊自柳李建新吝章国刘宏强张鹏刘天武赵燕青
Owner HEBEI IRON AND STEEL
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