CN102181609A

CN102181609A - Desulfurization method for smelting two-phase stainless steel

Info

Publication number: CN102181609A
Application number: CN 201110126703
Authority: CN
Inventors: 刘卫东
Original assignee: Shanxi Taigang Stainless Steel Co Ltd
Current assignee: Shanxi Taigang Stainless Steel Co Ltd
Priority date: 2011-05-17
Filing date: 2011-05-17
Publication date: 2011-09-14

Abstract

The invention discloses a desulfurization method for smelting two-phase stainless steel, belonging to desulfurization technologies for refining molten steel through an argon oxygen decarburization furnace in the field of metallurgy. The method comprises the steps of desulfurization at a reduction period in the argon oxygen decarburization furnace and slagging desulfurization in the argon oxygen decarburization furnace, and is characterized in that: slagging desulfurization in a furnace rear ladle is performed after the slagging desulfurization in the argon oxygen decarburization furnace and is carried out by completely removing slag in the furnace rear ladle, adding aluminum blocks or aluminum pills, lime and fluorite into the ladle and stirring for 10 minutes by using strong bottom blowing. In the method, desulfurization is performed three times, so that S content in steel is less than or equal to 0.003 percent, control requirement of the two-phase stainless steel on sulfur content is completely met, damages to thermal plasticity by sulfur during rolling of the two-phase stainless steel is reduced, and a corrosion resisting performance is improved.

Description

A kind of two-phase stainless smelting steel sulfur method

Technical field

The invention belongs to the desulfurization technology of field of metallurgy, be specifically related to a kind of two-phase stainless smelting steel sulfur method the argon oxygen decarburizing furnace refined molten steel.

Background technology

Duplex stainless steel is a kind of high chromium low nickel stainless steel, because of it has the advantage of ferritic stainless steel, austenitic stainless steel concurrently, have superior intergranular corrosion resistance, anti-spot corrosion, anticorrosion stress-resistant performance and superior mechanical property, therefore be widely used in fields such as petrochemical complex, flue gas desulfurization, bridge manufacturing.

With the S32205 duplex stainless steel is example, and micro-component content requirement is in the steel: C≤0.03%, Si≤1.00%, Mn≤2.50%, P≤0.030%, S≤0.010%, Cr are 22.00%-23.00%, Ni is 4.50%-6.50%, and Mo is 3.00%-3.50%, and N is 0.14%-0.20%.

Therefrom as can be seen, the requirement of sulphur content is very low in the two-phase stainless steel to steel.

The sulfur method of present argon oxygen decarburizing furnace refined molten steel generally adopts the secondary desulfurization, i.e. the 1st desulfurization is reduction period desulfurization in the argon oxygen decarburizing furnace, and the 2nd desulfurization is slag making desulfurization in the argon oxygen decarburizing furnace stove.Because of duplex stainless steel belongs to the Ultra-low carbon high chromium-stainless steel, the decarburization difficulty, so decarburization end back molten steel peroxidation is serious, causes bad desulfurization effects, generally adopting the secondary sulfur method is directly sulphur to be taken off to below 0.0050%.

Summary of the invention

The invention provides a kind of two-phase stainless smelting steel sulfur method, this method can guarantee that two-phase stainless product made from steel sulphur content is stable and be controlled at below the 30ppm.

The present invention includes reduction period desulfurization in the argon oxygen decarburizing furnace, slag making desulfurization in the argon oxygen decarburizing furnace stove, it is characterized in that carrying out after the slag making desulfurization in the argon oxygen decarburizing furnace stove slag making desulfurization in the ladle behind the stove, the working method of the interior slag making desulfurization of ladle is that ladle scratches clean slag behind the stove behind the stove, in bag, add aluminium block or aluminum shot, lime, fluorite, use strong bottom blowing to stir 10 minutes.

175 tons of argon oxygen decarburizing furnace refining duplex stainless steel molten steel desulfurizings, 6.0 tons of required reduction ferrosilicon, 4.8 tons in lime, 3.7 tons in fluorite, 0.7 ton of aluminium block or aluminum shot, 2.8 tons in lime, 0.2 ton in fluorite, wherein the desulfurization of argon oxygen decarburizing furnace reduction period adds 6.0 tons of ferrosilicon of reduction, 2.0 tons in lime, 3.5 tons in fluorite, secondary slag making desulfurization adds aluminium block or 0.5 ton of aluminum shot, 2.0 tons in lime in stove in the argon oxygen decarburizing furnace stove, slag making desulfurization adding aluminium block or 0.2 ton of aluminum shot, 0.8 ton in lime, 0.2 ton in fluorite in bag in the ladle.

Described aluminium block can replace with aluminum shot.

The present invention is through 3 desulfurization, can reach to contain S≤0.003% in the steel, satisfies the control requirement of duplex stainless steel to sulphur content fully, reduces sulphur to thermoplastic harm in the duplex stainless steel operation of rolling, and improves corrosion resisting property.

Embodiment:

Embodiment: the reaction vessel of present embodiment is: capacity is the ladle that 180 tons argon oxygen decarburizing furnace and capacity are 190 tons, and matallurgical products is: the S32205 duplex stainless steel.

In argon oxygen decarburizing furnace, be blended into 165 tons of smelting mother liquor of stainless steel from electric furnace and finish the desulfurization of carrying out 175 tons of argon oxygen decarburizing furnace refined molten steel after the dual phase steel decarburized alloyization.

Wherein, mass percent composition such as following table in the mother liquor of stainless steel:

C%

Si%

Mn%

P%

S%

Cr%

Ni%

1.0-1.5

≤0.50

≤1.00

≤0.030

20.00-2100

1.50-2.50

Step 1: reduction period desulfurization in the argon oxygen decarburizing furnace, be that oxygen decarburization to C content≤0.02% can enter reduction step, promptly add 6.0 ± 1.0 tons of low-carbon ferrosilicons, 2.0 ± 0.5 tons in lime, 3.5 ± 0.5 tons in fluorite, stir reduction 10 minutes, S content in the steel can be reduced to about 0.008% from 0.030%;

Slag making desulfurization in step 2 argon oxygen decarburizing furnace.Be that the stove that falls was outwelled 90% reducing slag after step 1 reduction finished, add 0.5 ton of aluminium block, 2.0 tons in lime in stove, bottom blowing nitrogen stirred 5 minutes, then tapping;

Step 3: the interior desulfurization of ladle behind the stove, promptly scratch clean slag in the ladle after the tapping, add 0.2 ton of aluminium block, 0.8 ton in lime, 0.5 ton in fluorite, argon bottom-blowing stirs desulfurization in 10 minutes then, and S content can reach below 0.0030% in the steel of desulfurization end back.

Claims

1. two-phase stainless smelting steel sulfur method, comprise reduction period desulfurization in the argon oxygen decarburizing furnace, slag making desulfurization in the argon oxygen decarburizing furnace stove, it is characterized in that carrying out after the slag making desulfurization in the argon oxygen decarburizing furnace stove slag making desulfurization in the ladle behind the stove, the working method of the interior slag making desulfurization of ladle is that ladle scratches clean slag behind the stove behind the stove, in bag, add aluminium block or aluminum shot, lime, fluorite, use strong bottom blowing to stir 10 minutes.

2. a kind of two-phase stainless smelting steel sulfur method according to claim 1 is characterized in that 175 tons of argon oxygen decarburizing furnace refining duplex stainless steel molten steel desulfurizings, 6.0 tons of required reduction ferrosilicon, 4.8 tons in lime, 3.7 tons in fluorite, 0.7 ton of aluminium block or aluminum shot ,2.8 tons in lime, 0.2 ton in fluorite ,Wherein the desulfurization of argon oxygen decarburizing furnace reduction period adds 6.0 tons of ferrosilicon of reduction, 2.0 tons in lime, 3.5 tons in fluorite, the slag making desulfurization adds aluminium block or 0.5 ton of aluminum shot, 2.0 tons in lime in stove in the argon oxygen decarburizing furnace stove, slag making desulfurization adding aluminium block or 0.2 ton of aluminum shot, 0.8 ton in lime, 0.2 ton in fluorite in bag in the ladle.