Technological process for removing fine occluded foreignsubstance in molten steel

A process method and inclusion technology, which is applied in the field of removing fine inclusions in molten steel, can solve problems such as inability to control fine inclusions, and achieve high collision probability and scientific and reasonable preparation

Active Publication Date: 2010-04-14
ANGANG STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Although the above method can remove inclusions to a certain extent, it cannot effectively control fine inclusions.

Method used

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  • Technological process for removing fine occluded foreignsubstance in molten steel
  • Technological process for removing fine occluded foreignsubstance in molten steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Transport the steel from the converter to the LF station for refining, measure the temperature and take samples, and adjust the composition. After the alloying is completed, stop argon blowing and inject powder; the conveying gas is Ar, and the conveying pressure is controlled at 0.01-1.2MPa, and the powder conveying rate is at 0.01~3kg / s, the feed rate is 0.3~1.5kg / t; stand still for 1~5min after powder spraying, then lightly treat with argon blowing, the delivery pressure is controlled between 0.13~0.2MPa, and the flow rate of argon gas is 50~120Nl / Min, the light treatment time of argon blowing is 3-10min, pouring directly on the machine after powder spraying, continuous casting adopts full protection pouring.

[0031] For the preparation of the powder, first, the low melting point pre-slag is prepared by taking 40kg of CaO, Al 2 o 3 35kg, SiO 2 10kg, MgO 10kg, CaF 2 Put 5kg into a mixer for uniform mixing, then melt and cool in a magnesia crucible, and then grind...

Embodiment 2

[0033] Transport the steel from the converter to the RH station for refining, vacuumize, measure temperature and sample, adjust the composition, and clean the cycle. After the alloying is completed, spray the powder and transport the gas as CO 2 , the conveying air pressure is controlled at 0.01-1.5MPa, the powder conveying rate is 0.01-3kg / s, and the feeding amount is 0.3-1.8kg / t. After powder spraying, the net cycle is 3 to 10 minutes, the vacuum is broken, moved out, poured on the machine, and the continuous casting adopts the whole process of protective pouring.

[0034] The preparation of powder, at first take CaO10kg, Al 2 o 3 50kg, SiO 2 5kg, MgO5kg, CaF 230kg prepares low-melting point pre-melting slag, its method is the same as embodiment 1; Get its particle diameter again according to formula ratio and be that the prepared low-melting point pre-melting slag 1kg of 1nm~3.5mm, magnesium oxide 98kg, magnesium carbonate 1kg enter stand Mix the materials uniformly in ...

Embodiment 3

[0036] Transport the steel from the converter to the CAS-OB station for refining, measure the temperature and take samples, and adjust the composition. When the alloying is finished, stop blowing argon, inject powder, and transport gas as Ar and CO 2 The mixed gas, the ratio of the two is 3:1, the delivery pressure is controlled at 0.01-1.8MPa, the powder delivery rate is 0.01-2.8kg / s, and the feeding amount is 0.3-1.8kg / t. After powder spraying, argon is blown lightly, the delivery pressure is controlled between 0.13-0.2MPa, and the flow rate of argon gas is 50-120Nl / min. The light treatment time of argon blowing is 3-10 minutes. After spraying the powder, it is poured directly on the machine, and the continuous casting adopts the whole process of protective pouring.

[0037] The preparation of powder, first take CaO70kg, Al 2 o 3 15kg, SiO 2 3kg, MgO 2kg, CaF 2 10kg prepares low-melting point pre-melting slag, its method is the same as embodiment 1; Getting its particle...

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Abstract

The invention relates to an external refining technology of various micro-alloy steels and special steels, in particular to a technology for removing slag inclusions in molten steel. The technology ofthe invention comprises the steps: a. molten steel is refined at LF, RH, VD or CAS-OB work position; b. a powder spraying technology is adopted to spray powder into the molten steel at the work positions; c. the molten steel is then directly cast on a machine after the powder spraying and the continuous casting adopts a whole-process protection casting. As the added powder has a scientific and reasonable prescription, when micro-air bubbles occur in the molten steel, the bubbles have high collision probability with the slag inclusions and fine slag drops have the function of wash heat and canalso effectively remove the slag inclusions in the molten steel. The technology of the invention can control the size and the quantity of the non-metallic inclusions in steel and the total oxygen amount to be 3ppm to 14ppm, the equivalent diameter of the impurities to be 0.5micron to 9micro and the average area of the impurities to be 0.002 percent to 0.008 percent, thus greatly improving the clearity of the molten steel and reducing the smelting cost.

Description

technical field [0001] The invention relates to an out-of-furnace refining process for various microalloy steels and special steels, in particular to a process for removing fine inclusions in molten steel, which is a process for secondary refining of various microalloy steels or special steels preferred process method. Background technique [0002] In recent years, due to the progress of ladle refining technology and continuous casting technology, the content of oxide-based non-metallic inclusions has been reduced, so that molten steel with excellent cleanliness can be produced. However, due to the use of steel and the harsh conditions of use, the requirements for inclusions in steel are more stringent. [0003] The harm of inclusions to steel is mainly related to the quantity and size of inclusions. To control the quality of inclusions, the most important thing is to control the quantity and size of inclusions. Due to different steel types and smelting cost constraints, t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21C7/04C21C7/076
CPCY02P10/20
Inventor 唐复平王晓峰刘万山孟劲松任子平李德刚陈本文王仁贵张军王文仲李镇张晓军孙群栗红
Owner ANGANG STEEL CO LTD
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