Production method of hot rolled steel strip Q355B for economical welded pipe

A technology of Q355B and production method, which is applied in the field of production of economical welded pipe hot-rolled steel strip Q355B, can solve the problems of difficult processing technology, affecting comprehensive processing performance, and serious Bauschinger effect, and achieves the reduction of Bauschinger effect, reduce the production of titanium oxide, and reduce the effect of coiling temperature

Active Publication Date: 2022-01-11
德龙钢铁有限公司
View PDF8 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The first method is simple in technology, but the cost is high, and has no considerable market benefits; the second method is more difficult in processing technology, but the quality of the billet is better, the cost is low, and there are considerable market benefits
The technical difficulty of the second process mainly lies in that titanium element has extremely active chemical properties, and it is easy to combine with oxygen and nitrogen so that the yield of Ti is low, resulting in many titanium inclusions in the steel, and the Bauschinger effect is serious, which reduces the The toughness of steel affects the comprehensive processing performance

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0051] Step ①: The carbon content of the Q355B hot-rolled steel strip for welded pipes of the present invention is 0.06% at the end point of converter smelting, and the content of sulfur element is 0.020%, and the temperature at the end point of converter smelting is controlled at 1650°C; The element content is 0.15%. Aluminum-containing materials are added for deoxidation during the tapping process. According to the manganese-carbon ratio ≥ 2.5, ferromanganese is added for alloying. The minimum manganese element content in the steel is calculated to be: 0.15%*2.5=0.375%; The sulfur element content is 0.020%, and the manganese-sulfur ratio is ≥ 15. The calculated minimum manganese element content in the steel is: 0.020%*15=0.3%. The content of manganese in steel is 0.375%. The converted ferromanganese alloy addition amount is (0.375-0.10) / 0.65 / 0.90*10=4.70kg / t, and the converter tapping amount is 100t, that is, the added ferromanganese alloy amount is 470kg.

[0052] Step ②: ...

Embodiment 2

[0060] Step ①: The carbon content of the Q355B hot-rolled steel strip for welded pipes of the present invention is 0.06% at the end point of converter smelting, and the content of sulfur element is 0.020%, and the temperature at the end point of converter smelting is controlled at 1645°C; carbon powder is added during the tapping process to make the carbon in the steel The element content is 0.17%. Aluminum-containing materials are added for deoxidation during the tapping process. According to the manganese-carbon ratio ≥ 2.5, ferromanganese is added for alloying. The minimum manganese element content in the steel is calculated to be: 0.17%*2.5=0.425%; The sulfur element content is 0.020%, and the manganese-sulfur ratio is ≥ 15. The calculated minimum manganese element content in the steel is: 0.020%*15=0.3%. Manganese element content is 0.425%. The converted ferromanganese alloy addition amount is (0.425-0.10) / 0.65 / 0.90*10=5.56kg / t, and the converter tapping amount is 100t, t...

Embodiment 3

[0069] Step ①: The carbon content of the Q355B hot-rolled steel strip for welded pipes of the present invention is 0.06% at the end point of converter smelting, and the content of sulfur element is 0.020%, and the temperature at the end point of converter smelting is controlled at 1650°C; The element content is 0.18%. Aluminum-containing material is added for deoxidation during the tapping process. According to the manganese-carbon ratio ≥ 2.5, ferromanganese is added for alloying. The minimum manganese element content in the steel is calculated to be: 0.18%*2.5=0.45%; The sulfur element content is 0.020%, and the manganese-sulfur ratio is ≥ 15. The calculated minimum manganese element content in the steel is: 0.020%*15=0.3%. Manganese element content is 0.45%. The converted ferromanganese alloy addition amount is (0.45-0.1) / 0.65 / 0.90*10=5.98kg / t, and the converter tapping amount is 100t, that is, the added ferromanganese alloy amount is 598kg.

[0070] Step ②: Bring the cont...

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
yield strengthaaaaaaaaaa
yield strengthaaaaaaaaaa
yield strengthaaaaaaaaaa
Login to view more

Abstract

The invention discloses a production method of a hot rolled steel strip Q355B for an economical welded pipe. The production method comprises the following steps of precise alloy content design, converter smelting, continuous casting, hot rolling and coiling, wherein the precise alloy content design step is conducted according to the following processes of a, determining the content of a carbon element; b, determining the content of a manganese element, specifically, determining a minimum value of the manganese content according to a manganese-carbon ratio and a manganese-sulfur ratio; and c, determining the content of a titanium element, specifically, calculating the content of the titanium element in steel according to a desired value of the yield strength of a product and a relational expression between the content of the carbon, manganese and titanium elements and the yield strength. According to the method disclosed by the invention, the elongation after fracture of the steel strip is improved and the Bauschinger effect is reduced by means of accurately determining the content of the elements such as carbon, manganese and titanium, controlling the chemical components in a narrow range, controlling the oxygen content in the steel, canceling an LF refining furnace process, increasing the temperature of a heating furnace, reducing the coiling temperature and the like. By adopting the method, the production cost is reduced by about 5.21 yuan / t under the same content of the carbon element, and the mechanical property of the steel strip is superior to that of the prior art.

Description

technical field [0001] The invention relates to a method for iron and steel smelting, in particular to a production method for economical welded pipe hot-rolled steel strip Q355B, which belongs to the technical field of iron and steel smelting. Background technique [0002] The iron and steel industry has now developed into one of the most internationally competitive industries in China, and the homogenization of competition in the domestic iron and steel market has become increasingly serious. For iron and steel enterprises, to maintain long-term stable operation, they must not only be satisfied with the production of iron and steel products, but also have High-efficiency, low-cost, and intelligent green manufacturing capabilities. For this reason, major domestic steel mills are boldly innovating and meticulous in product manufacturing processes based on product processing characteristics. The Q355B hot-rolled steel strip for welded pipe implements the GB / T3274 standard of ...

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): C22C33/06C21C7/06C21C7/072C21C7/00C22C38/04C22C38/02C22C38/06C22C38/14B21B1/22B21B37/74
CPCC22C33/06C21C7/06C21C7/072C21C7/0025C22C38/04C22C38/02C22C38/06C22C38/14B21B1/22B21B37/74Y02P10/20
Inventor 黄伟丽杨志刚王信威陈四平牛跃威徐子谦朱云杰张立广东根来
Owner 德龙钢铁有限公司
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