Rolling process for refining M-A components in low-carbon bainite steel

A carbon bainite steel and low carbon bainite technology is applied in the field of rolling technology for refining M-A components in low carbon bainite steel, and can solve the problem of strength, toughness, performance stability and thickness direction of thick steel plates. Lack of performance uniformity regulation, high yield-to-strength ratio, and strength that does not meet service requirements, etc., to achieve the effect of easy implementation of the preparation plan, easy control of the production process, low cost and stable batch industrial production

Active Publication Date: 2021-12-21
YANSHAN UNIV
View PDF12 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the coarse M-A components can be decomposed by tempering heat treatment to achieve the purpose of improving the low-temperature toughness at 1 / 4 of the thickness of the plate, but due to insufficient rolling and cooling penetration in the center, it is difficult to improve the low-temperature toughness of the center, and the thickness cannot be completely solved. Thickness performance uniformity problem
[0007] The authorized announcement numbers are CN1323187C, CN103451537B and CN103451561B and other invention patents. By adjusting the alloy composition and controlling the addition of lower elements such as C, Si, Mn or Cr, to reduce the brittle phase of M-A components, it is beneficial to improve the impact toughness of the base metal , but the tensile strength is often insufficient, the yield ratio is high, and the strength does not meet the service requirements
[0008] It can be seen that in the current research, most of the alloy composition or heat treatment process is used to regulate the M-A component, and the research on the regulation of the M-A component through the rolling process is not deep enough, resulting in the strength and toughness, performance stability and thickness of the thick gauge steel plate. There are still many deficiencies in the control of uniformity of performance, and the development of related preparation technology is urgently needed

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
  • Rolling process for refining M-A components in low-carbon bainite steel
  • Rolling process for refining M-A components in low-carbon bainite steel
  • Rolling process for refining M-A components in low-carbon bainite steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0026] The invention provides a rolling process for refining the M-A component in the structure of low-carbon bainite steel, which includes the following steps.

[0027] (1) Heating stage: the slab is heated at T 1 Heating to 1100~1200℃ within 1 minute, keep warm T 2 minutes, and 280≤T≤352, where T=T 1 +T 2 ,T 1 =(0.80~1.10)H,T 2 =(0.14~0.22)H, H is the thickness of the slab (mm).

[0028] (2) Rolling stage, including rough rolling stage and finish rolling stage.

[0029] In the rough rolling stage, the starting rolling temperature is 1020-1080°C, the final rolling temperature is 980-1060°C, and the intermediate billet is formed in 3-5 rolling passes. The reduction rate of a single pass is ≥12%, and the total reduction rate is not less than 55. %.

[0030] Intermediate billet thickness h=(1.8~2.2)t, t is the final target thickness of the steel plate (mm). The water spray device next to the intermediate billet to be warmed will spray water to accelerate the cooling of t...

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
sizeaaaaaaaaaa
thicknessaaaaaaaaaa
yield strengthaaaaaaaaaa
Login to view more

Abstract

The invention discloses a rolling process for refining M-A components in low-carbon bainite steel and belongs to the technical field of steel production. The rolling process comprises three steps of heating, rolling and cooling. The rolling process has the following beneficial technical effects: (1), the average size of the M-A components in the low-carbon bainite steel is not greater than 1.5 microns; (2), the average value of KV2 impact energy at 40 DEG C below zero of typical positions (1/4 position and 1/2 position) in a thickness direction of a low-carbon bainite steel plate with high thickness of more than 50mm is not less than 200J, and the difference value between single values is not greater than 20J; (3), the yield strength of typical positions (1/4 position and 1/2 position) in the thickness direction of the low-carbon bainite steel plate with high thickness of more than 50mm is 521-595MPa, the tensile strength is 652-710MPa, the yield ratio is 0.79-0.85, and the elongation rate is 19-23%; and (4), the preparation scheme of the low-carbon bainite steel is easy to implement, the production process is easy to control, low-cost stable batch industrial production can be realized, and the construction requirements of main bearing structures such as bridges, buildings, maritime work, pipelines, wind power towers and the like on high-thickness and high-strength steel can be met.

Description

technical field [0001] The invention belongs to the technical field of iron and steel manufacturing, and particularly relates to a rolling process for refining M-A components in low-carbon bainite steel. The steel plate produced by this process has excellent low-temperature toughness and performance stability, and is well uniform in thickness direction . Background technique [0002] In recent years, low-carbon bainitic steel has been widely used in bridges, construction, marine engineering, pipelines, wind power towers and other fields due to its excellent strength, toughness and weldability. In the actual production process of low-carbon bainite steel, phase transformation occurs in the continuous cooling process to form all or a certain amount of granular bainite room temperature structure. When the rolling or cooling penetration is insufficient, especially for steel plates with a thickness of more than 50mm, the size of the martensite-austenite component (M-A component)...

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): B21B1/38B21B37/74C21D8/02C21D11/00C22C38/00C22C38/02C22C38/04C22C38/42C22C38/44C22C38/46C22C38/48C22C38/50C22C38/58
CPCB21B1/38B21B37/74C22C38/02C22C38/04C22C38/58C22C38/42C22C38/44C22C38/48C22C38/46C22C38/50C22C38/001C21D8/0205C21D8/0226C21D8/0247C21D11/005C21D2211/002B21B2001/386
Inventor 王青峰赵丽洋谯明亮陈林恒陈克坚崔强高燕戴胜勇王军陈建峰张志勇杨啸雨刘东博
Owner YANSHAN UNIV
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