Check patentability & draft patents in minutes with Patsnap Eureka AI!

Q550D high-strength steel with ultra-low carbon equivalent and production method thereof

A production method and ultra-low carbon technology, applied to ultra-low carbon equivalent Q550D high-strength steel and its production field, can solve the problems of unstable weldability, high and low strength and low plasticity of hot-rolled high-strength steel, and low impact power value, etc. The effect of low cost and short process flow

Inactive Publication Date: 2015-09-23
NANJING IRON & STEEL CO LTD
View PDF4 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In view of the defects in the above-mentioned prior art, the purpose of the present invention is to propose a low-carbon plus a small amount of chromium alloy and Nb, Ti, B micro-alloying composition design to solve the problem of high strength and low plasticity and low impact energy of hot-rolled high-strength steel. Q550D high-strength steel with ultra-low carbon equivalent and production method thereof

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
  • Q550D high-strength steel with ultra-low carbon equivalent and production method thereof
  • Q550D high-strength steel with ultra-low carbon equivalent and production method thereof
  • Q550D high-strength steel with ultra-low carbon equivalent and production method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] A kind of Q550D high-strength steel with ultra-low carbon equivalent provided in this embodiment is produced by a reversible four-high rolling mill with a thickness of 30 mm as the rough rolling mill with a rolling force of 5,000 tons and a finishing mill with a rolling force of 4,000 tons. The standard Q550D high-strength steel is taken as an example. The specific element composition refers to Table 1, and the balance is Fe and unavoidable impurities.

[0025] The present invention also relates to a production method of the 30mm ultra-low carbon equivalent Q550D high-strength steel, the method comprising molten iron desulfurization pretreatment→converter smelting→RH refining→(LF refining)→continuous casting→slab stacking and slow cooling→slab inspection → Slab identification → Slab acceptance → Slab heating → Descaling → Rolling → Cooling → (Flaw detection) → Cutting, sampling → Printing marking → Inspection → Storage and other steps. details as follows:

[0026] Tabl...

Embodiment 2

[0040] An ultra-low carbon equivalent Q550D high-strength steel provided in this embodiment is also taken as an example of a Q550D high-strength steel with a thickness specification of 30mm. The difference is the mass percentage of various elements, as shown in the following table:

[0041] Table 1-1 The actual weight percentage of the chemical composition of Q550D high-strength steel with a thickness of 30 mm

[0042]

[0043] Considering high strength and high impact performance requirements at -20°C, the medium-thickness steel plate enters the cooling device from 790-810°C and is cooled to 450-490°C in a short period of time. In the composition design, a small amount of low carbon is used to improve hardenability The Cr and B elements can improve the cooling rate and design ideas to meet the production requirements of high-grade equipment.

[0044] Table 2-1 Heating process

[0045]

[0046] Due to the high strength of the experimental steel, the 30mm thin-gauge stee...

Embodiment 3

[0053] An ultra-low carbon equivalent Q550D high-strength steel provided in this embodiment is also taken as an example of a Q550D high-strength steel with a thickness specification of 30mm. The difference is the mass percentage of various elements, as shown in the following table:

[0054] Table 1-2 The actual weight percentage of the chemical composition of Q550D high-strength steel with a thickness of 30 mm

[0055]

[0056] Considering high strength and high impact performance requirements at -20°C, the medium-thickness steel plate enters the cooling device from 790-810°C and is cooled to 450-490°C in a short period of time. In the composition design, a small amount of low carbon is used to improve hardenability The Cr and B elements can improve the cooling rate and design ideas to meet the production requirements of high-grade equipment.

[0057] Table 2-2 Heating process

[0058]

[0059] Due to the high strength of the experimental steel, the 30mm thin-gauge stee...

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 relates to Q550D high-strength steel with ultra-low carbon equivalent. The Q550D high-strength steel comprises, by weight, 0.05% to 0.07% of C, 0.2% to 0.3% of Si, 1.4% to 1.6% of Mn, not greater than 0.015% of P, not greater than 0.003% of S, 0.15% to 0.2% of Cr, 0.03% to 0.04% of Nb, 0.01% to 0.02% of Ti, not greater than 0.002% of B, not greater than 0.035% of Als, not greater than 0.35% of Ceq, and the balance of Fe plus unavoidable impurity. The technical difficulty that hot-rolled high-strength steel has high strength but low plasticity, low impact energy and instable weldability is successfully solved, and the demands of mine machinery, engineering machinery and carrier vehicles for welding structure materials are well met.

Description

technical field [0001] The invention relates to a production method of high-strength steel, in particular to an ultra-low carbon equivalent Q550D high-strength steel and a production method thereof. Background technique [0002] High-strength structural steel is a resource-saving product with high technical content and high added value. Low-alloy high-strength steel has strong applicability and is mainly suitable for welding construction. Therefore, not only requires steel to have high strength and plastic toughness, It also has good weldability and processability. As a low-alloy high-strength structural steel, Q550D is the most widely used high-strength steel because of its high strength, good toughness, good processing performance and good welding performance. It is mainly used in construction machinery, coal mining machinery, shipbuilding and Steel structures and other fields. In recent years, Q550D steel plate has a low one-time pass rate due to special reasons such as...

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): C22C38/38C22C38/32C22C38/28C21D8/02
Inventor 郑建平侯中华杨海涛牛继龙姜在伟李堂夏成胜
Owner NANJING IRON & STEEL CO LTD
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com