Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Efficient circulation modification smelting method for RH furnace steel ladle top slag

A smelting method and upgrading technology, which is applied in the field of iron and steel metallurgy and steelmaking, can solve the problems of product composition stability and the influence of pass rate, the modifier cannot fully react with the slag surface, and the carbon at the end of the decarburization effect is too high, so as to avoid Secondary oxidation pollution, good kinetics and slag adsorption capacity, solve the effect of improving the inclusion removal function

Inactive Publication Date: 2018-09-28
SHANDONG IRON & STEEL CO LTD
View PDF4 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the excessive addition of the ladle top slag modifier in the early stage and excessive deoxidation, oxygen transfer and aluminum deoxidation reactions will occur at the steel slag interface, the reaction rate of oxygen and carbon in molten steel will slow down, and the decarburization effect and end point carbon tend to be too high , which has a great impact on the product's compositional stability and pass rate
[0005] Insufficient modification of ladle top slag: Converter-RH furnace-slab continuous casting machine smelting process is adopted. The modifier is usually added when the RH furnace is repressed and exits the station. Because the top slag is prone to crusting problems, it cannot Fully react with the slag surface, the modification effect is obviously insufficient
At the same time, the modification is carried out at this time, and the addition is late according to the process reasoning. Because the molten steel is completely deoxidized after alloying, but the total oxygen of the top slag is high, it will inevitably cause a direct reaction at the interface of the steel slag, which will affect the purity of the molten steel.

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
  • Efficient circulation modification smelting method for RH furnace steel ladle top slag

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] combine figure 1 As shown, a RH furnace ladle top slag efficient circulation upgrading smelting method. In the present invention, the slag is modified after deep decarburization and alloying in the RH furnace; the vacuum degree of the vacuum tank is controlled within 20-30 Pa; the depth of the dipping tube inserted into the molten steel is between 250-300 mm; The argon circulation gas rises into the vacuum tank 1, and the molten steel flows into the ladle 4 from the downcomer 3 after being degassed, and the molten steel forms a closed loop flow on the upper layer of the ladle 4; at the same time, the ladle bottom blowing 5 bottom blowing argon at the ladle ascending pipe position (the pressure is 0.2 ~0.4Mpa, the flow rate is 30~50NL / min); the amount of modifier 6 added in the vacuum tank 1 is 200~300kg, and the ladle slag is deoxidized and modified by using the rapid reaction of the steel slag interface.

[0029] An RH furnace ladle top slag efficient circulation upgr...

Embodiment 2

[0037]When smelting strip ultra-low carbon steel (grade: DCO4-S), the converter-RH furnace-CC process is adopted, and the RH furnace adopts the deep treatment smelting mode. Furnace number H183-1250, continuous casting machine section 175×1270mm, entry temperature 1601°C, oxygen 450ppm; oxygen blowing temperature rise 25°C; vacuum pump to full pump (level 5), vacuum degree controlled within 67pa, end point after natural decarburization of molten steel Carbon: 13ppm; add 140kg of aluminum particles + 110kg of high titanium for deoxidation and alloying; operate according to the steps of the invention, recompress and leave the station to sample and analyze the top slag of the ladle, the results are shown in Table 1:

[0038] Table 1 Sampling and analysis results of ladle top slag

[0039] TF

Embodiment 3

[0041] When smelting strip ultra-low carbon steel (grade: DCO4), the converter-RH furnace-CC process is adopted, and the RH furnace adopts the deep treatment smelting mode. Furnace number H181-1420, cross-section of continuous casting machine 175×1270mm; entry temperature 1611°C, oxygen 480ppm; oxygen blowing temperature rise 15°C; vacuum pump to full pump (level 5), vacuum degree controlled within 67pa, end point after natural decarburization of molten steel Carbon: 14ppm; add 150kg of aluminum particles + 110kg of high titanium for deoxidation and alloying; operate according to the steps of the invention, repress and leave the station to sample and analyze the top slag of the ladle, the results are shown in Table 2:

[0042] Table 2 Sampling and analysis results of ladle top slag

[0043] TF

SiO 2

CaO

MgO

Alkalinity

Al 2 o 3

1.59

6.0

36.75

6.76

6.13

23.12

[0044] From the results of the invention examples, when s...

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 efficient circulation modification smelting method for RH furnace steel ladle top slag. The modification smelting method includes the following steps that 1), after RH furnace circulation deep decarbonization is completed, aluminum particles / ferrotitanium is added for deoxygenation alloying, the vacuum degree of a vacuum tank is reduced to 20-30 kpa, and closed circulation is formed by molten steel in the vacuum tank and molten steel on the upper layer of a steel ladle; 2), 200-300 kg of modifier is weighed from an alloy material bin, and the modifier is added into the vacuum tank through an alloy vacuum hopper; 3), steel ladle bottom argon blowing is started, the pressure is adjusted to be 0.2-0.4 Mpa, the flow is 30-50 NL / min, and it is guaranteed that the steel ladle top slag slightly moves and the molten steel is not exposed; and 4), the modifier is added for circulation for 3-4 min, the steel ladle bottom argon blowing is stopped, the vacuum degree of the vacuum tank is controlled below 67 pa, the top slag is re-pressed after pure circulation is carried out for 8-10 min, and the top slag is delivered out of a station. The furnace slag total iron is controlled within 2%, the purity degree of the molten steel is increased, the continuous casting pouring continuous pulling charge number is 10, and the quality of casting blanks and rolled metal is obviously improved.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy and steelmaking, and in particular relates to a high-efficiency circulation upgrading smelting method for RH furnace ladle top slag. Background technique [0002] With the simultaneous and rapid development of domestic metallurgical equipment and technology, special steel products have been more extensively developed and applied. RH vacuum furnace originated in Germany and developed in Japan. In recent years, it has been rapidly applied and developed in China, and the smelting products are increasing, including thick plate high strength, pipeline, ship plate, pressure vessel, and broadband cold-rolled ultra-low carbon deep-drawing steel and silicon steel. Wait. Among them, when smelting ultra-low carbon and other deep-drawing steels, the converter-RH furnace-slab continuous casting machine smelting process is adopted, and the LF refining furnace is not used for deoxidation and slagging op...

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): C21C7/10C21C7/068C21C7/06
CPCC21C7/10C21C7/0006C21C7/06C21C7/068
Inventor 邹春锋韩蕾蕾
Owner SHANDONG IRON & STEEL CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products