Technological method of using high-phosphorus molten iron to produce ultralow-phosphorus steel

A process method, the technology of ultra-low phosphorus steel, applied in the field of iron and steel smelting, can solve the problems of deterioration of steel impact toughness, cold brittleness, and increase of steel ductile-brittle transition temperature, so as to reduce phosphorus content, reduce production costs, and optimize steelmaking process The effect of the process

Active Publication Date: 2019-05-21
BAOTOU IRON & STEEL GRP
View PDF8 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Phosphorus is a harmful element in steel. Phosphorus will increase the ductile-brittle transition temperature of steel, deteriorate the impact toughness of steel, and cause cold and brittle

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
  • Technological method of using high-phosphorus molten iron to produce ultralow-phosphorus steel
  • Technological method of using high-phosphorus molten iron to produce ultralow-phosphorus steel
  • Technological method of using high-phosphorus molten iron to produce ultralow-phosphorus steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] 1. Pretreatment of KR molten iron: The labels of the 7 furnaces of molten steel produced by continuous smelting are 1 to 7 in sequence. %.

[0040] Table 1 Situation of molten iron after KR desulfurization treatment (%)

[0041]

[0042]

[0043] 2. Converter smelting: control the final slag alkalinity, the blowing temperature at the end point; block the slag and tap the steel, blow the argon gas at the bottom of the ladle before tapping and stir for 1-2 minutes, and blow the argon gas at the bottom of the ladle to stir during the tapping process, and do not add molten steel for deoxidation agent and slag deoxidizer; the end temperature of converter smelting, the basicity of final slag and the composition of tapping molten steel are listed in Table 2. It can be seen from Table 2 that the P content of the steel is 0.0065-0.0123%, and the average dephosphorization rate is 94.1%. Furthermore, by controlling the end point temperature at 1600-1620°C, the P content ca...

Embodiment 2

[0054] 1. Pretreatment of KR molten iron: the grades of the 4 furnaces of molten steel produced by continuous smelting are 8-11 in sequence. %.

[0055] Table 5 Situation of molten iron after KR desulfurization treatment

[0056] label

[0057] 2. Converter smelting: control the final slag alkalinity, the blowing temperature at the end point; block the slag and tap the steel, blow the argon gas at the bottom of the ladle before tapping and stir for 1-2 minutes, and blow the argon gas at the bottom of the ladle to stir during the tapping process, and do not add molten steel for deoxidation agent and slag deoxidizer; converter smelting end temperature, final slag basicity and tapping molten steel composition are listed in Table 6. It can be seen from Table 2 that the content of P in the steel is 0.010-0.012%.

[0058] Table 6 Composition of tapping at the end of converter (%) and end temperature of blowing (℃)

[0059] label

[0060] 3. LF refining: during...

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 the field of steel and iron smelting, in particular to a technological method of using high-phosphorus molten iron to produce ultralow-phosphorus steel. The technological method comprises the steps that pretreatment of the KR molten iron is conducted; converter smelting is conducted, specifically, the alkalinity of final slag is controlled to range from 3.0 to 4.5, and thefinishing point converting temperature is controlled to range from 1600 DEG C to 1620 DEG C; slag stopping and steel tapping operation is conducted, specifically, molten steel deoxidizing agents andfurnace slag deoxidizing agents are not added in the steel tapping process; LF refining operation is conducted, specifically, high-alkalinity furnace slag is generated in the refining process, argon is blown to the bottom of a steel ladle, stir operation is conducted, and the temperature of molten steel ranges from 1520 DEG C to 1560 DEG C; the slag is removed, and slag formation is conducted again; and deoxidization treatment is conducted. By the adoption of the technology, the molten steel which is formed by the molten iron can be used, the phosphorus content of the molten iron is larger than 0.160%, the content of the component P element which is processed can be stably lower than or equal to 0.005%, the minimum content of the P element can be 0.002%, the requirements of various steel grades for the component P element of the molten steel can be met, the purpose of producing the ultralow-phosphorus steel can also be achieved, and the technological control process is stable and reliable.

Description

technical field [0001] The invention relates to the field of iron and steel smelting, in particular to a process for producing ultra-low-phosphorus steel by using high-phosphorus molten iron. Background technique [0002] Phosphorus is a harmful element in steel. Phosphorus will increase the ductile-brittle transition temperature of steel, deteriorate the impact toughness of steel, and cause cold brittleness. Phosphorus is also a strong segregation element in steel, which can easily lead to segregation in the center of the slab during the solidification of molten steel, causing cracks in the middle of the slab. Phosphorus comes from the ore used as raw material for ironmaking, and dephosphorization is one of the main tasks in steelmaking. At present, high-quality steel products such as automobile steel, low-temperature oil and gas pipeline steel, and industrial pure iron have very low requirements on the phosphorus content of molten steel. Iron and steel plants continue to...

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): C22C33/04C21C5/36C21C7/064C21C7/06
CPCY02P10/20
Inventor 杨峰罗海明张嘉华刘少峰陈胜魏晓东段云波董磊
Owner BAOTOU IRON & STEEL GRP
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