Annealing method of ultrahigh-strength hot-forming steel

A hot forming and intense heating technology, applied in the field of heat treatment of high-strength automotive steel, can solve the problems of high energy consumption and long production cycle, and achieve the effects of improving production efficiency, saving costs and reducing energy consumption

Inactive Publication Date: 2013-12-25
UNIV OF SCI & TECH BEIJING
View PDF1 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the current recrystallization bell annealing process h

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
  • Annealing method of ultrahigh-strength hot-forming steel
  • Annealing method of ultrahigh-strength hot-forming steel
  • Annealing method of ultrahigh-strength hot-forming steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Heat the cold-rolled steel plate to 780°C, hold it for 10 minutes, then cool it to 700°C at a cooling rate of 1°C / s, hold it for 1 hour, and finally cool it to room temperature at a cooling rate of 1°C / s. The microstructure after annealing is ferrite + granular carbide, the recrystallization of ferrite is not complete, and the fiber structure of the cold-rolled state is still retained, and the distribution of granular carbide is uneven.

Embodiment 2

[0025] Heat the cold-rolled steel plate to 780°C, hold it for 0.5h, then cool it to 700°C at a cooling rate of 1°C / s, hold it for 1h, and finally cool it to room temperature at a cooling rate of 1°C / s. The microstructure after annealing is ferrite + granular carbide, the recrystallization of ferrite is basically completed, and the granular carbide is dispersedly distributed on the ferrite matrix. Embodiment three

Embodiment 3

[0026] Heat the cold-rolled steel plate to 780°C, hold it for 1 hour, then cool it to 700°C at a cooling rate of 1°C / s, hold it for 1 hour, and finally cool it to room temperature at a cooling rate of 1°C / s. The microstructure after annealing is ferrite + granular carbide, the recrystallization of ferrite is completed, and the granular carbide is dispersed on the ferrite matrix.

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 an annealing method of ultrahigh-strength hot-forming steel, belonging to the technical field of heat treatment on high-strength automobile steel. After hot rolling and cold rolling, the ultrahigh-strength hot-forming steel is subjected to annealing treatment to obtain a steel plate substrate before hot forming. The hot rolling process comprises the steps of heating a hot-rolled plate blank to 1,100-1,250 DEG C, and preserving heat for 0.5-1 hour, wherein the final rolling temperature is 800-900 DEG C, the coiling temperature is 600-700 DEG C, and the cold rolling reduction rate is 70-80%. The annealing process comprises the steps of slowly heating the cold-rolled steel plate to a two-phase region (alpha+gamma), namely a temperature above A1; preserving heat for 0.1-5 hours; cooling to a temperature below A1 at a cooling speed of 0.1-10 DEG C per second; preserving heat for 0.1-5 hours; finally, cooling to room temperature at a cooling speed of 0.1-10 DEG C per second. According to the ultrahigh-strength hot-forming steel prepared by the method disclosed by the invention, granular carbides are dispersed on a ferrite matrix of the microscopic structure of the steel plate before hot forming, the carbides are uniformly distributed, the reversion and re-crystallization of the ferrite are sufficient, and the sufficiency and uniformity of austenitizing in a hot forming heating stage are facilitated; compared with a traditional cover annealing process, the annealing time is short, and the production efficiency is high.

Description

technical field [0001] The invention belongs to the technical field of heat treatment of high-strength automobile steel, and in particular relates to an annealing method of ultra-high-strength hot-formed steel. Background technique [0002] With the development of the automobile industry, energy saving and emission reduction has become the focus of common attention in the world today. Automobile lightweight is the main measure to achieve this goal, and more advanced high-strength steel and ultra-high-strength steel are widely used in automobile bodies. [0003] Usually, ultra-high-strength automotive steel with a tensile strength greater than 1000MPa has a narrow range of plastic deformation due to its high strength, poor formability, and requires a large stamping force. When stamping and deforming at room temperature, it is easy to crack, and the springback of the parts after forming is serious, resulting in poor dimensional and shape stability of the parts, and it is more...

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): C22C38/38C22C38/34C22C38/32C21D8/00C21D1/26
Inventor 陈银莉程俊业赵爱民丁然苏岚赵征志佟婷婷张帆
Owner UNIV OF SCI & TECH BEIJING
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