VOD furnace uses property of magnesian chromic firebrick

Craft of VOD furnace decarbonization, it is a kind of technology that is used at element of material emergence carbon.

When stainless steel of VOD furnace fine, content of the C when steel fluid enters furnace, Si is exorbitant it is the immediate cause that causes accident of splash of the process that blow oxygen. The basis produces practice, put forward two kinds to reduce what splash accident produces odds to optimizeVacuum is spentAdjust means, lengthen 2×10 namely⁴Pa dwell time; 3×10⁴Pa and 2×10⁴Two paragraphs of type protect Pa pressure. When C≥0.65% of fluid of the steel that enter furnace, Si≥0.20% , use the vacuum after optimizing to spend adjust means, can prevent the splash accident of the process that blow oxygen effectively, improve VOD smelt quality and efficiency.

Vacuum of VOD(Vacuum Oxygen Decarburization) blows oxygen decarbonization craft, it is the CO that uses vacuum to reduce decarbonization to react cent is pressed, improve technology of the fine outside the stainless steel furnace of decarbonization efficiency thereby, it is very easy that because be in,vacuum condition falls the carbon in steel fluid purify arrives very low level, accordingly, this fine method basically uses 2 Yu Chaochun, fine that exceed low carbon stainless steel and alloy. The decarbonization that the core function of stainless steel of VOD furnace fine is steel fluid protects chromium, its fine process includes to blow oxygen decarbonization and reductive take off gas 2 phase. Vacuum of phase of the decarbonization that blow oxygen is spent adjust to raising decarbonization smelt quality is mixed efficiency, avoid steel fluid splash to wait to having crucial effect.

One, the basic function of VOD

VOD law issues a kind of method that has smelt stainless steel for vacuum condition, have following typical metallurgy functions:

(1) blows oxygen decarbonization. The carbolic content in speed of decarbonization of tall carbon area and steel has nothing to do, by decision of the quantity that feed oxygen, speed of decarbonization of low carbon area decreases along with content of the carbon in steel and reduce.

(2) goes carbon protects chromium. Close chromicly so that lead tenability to be in 98.5%~99.5% .

(3) blows oxygen to warm up. Rely on a metal (silicon, manganese, chromic, iron, aluminium) the temperature that the exothermic that oxidation reacts will come to raise smelt molten steel.

(4) vacuum takes off gas. It is OK to blow argon and vacuum to spend quicken gas to diffuse mediumly in steel fluid, be helpful for taking off gas.

(Be mingled with of 5) slagging, to oxigenate, to decoke, purify. The tall alkalinity broken bits that builds reproducibility is helpful for deoxidization and to decoke.

(6) alloy is changed. Alloy is joined to be able to raise the close so that lead and controls molten steel well and truly part of alloy below vacuum condition.

2, VOD furnace is mixed to the action of fireproof material requirement

1, course of VOD furnace fine is right the action of fireproof material

VOD leaves the smelt stainless steel of the decarbonization that blow oxygen, fine unit that exceeds mild steel and alloy for vacuum condition. The action of fireproof to lining in fine process material basically has:

(1) vacuum high temperature. VOD furnace is in below vacuum when smelt, the vacuum inside furnace spends 66.66~133.32Pa, at the same time the temperature inside furnace can achieve 1700 ℃ above.

(2) alkalinity changes. Alkalinity is 0.5~4, the alkalinity change of slag is big, erode to lining material strong. Smelt initial stage is low alkalinity slag, later period goes to protect chromium sulfur, the requirement builds slag of reproducibility tall alkalinity, alkalinity can amount to 4 above.

(Flow of 3) steel fluid and loop are fast. Because at the same time gush blows argon gas and oxygen, aeriform agitate action is strong, steel fluid and slag are right of lining material erode and wear away big.

(Action of 4) thermal shock is violent. VOD furnace operates facility for intermittence, use 2~3 everyday second, temperature change is so big, the temperature change of fireproof material is acuteness, impact of be heated shake is big.

(Time of effect of 5) high temperature is long. Because smelt time is long, it is 1h left and right sides commonly, lining material should suffer effect of long vacuum high temperature.

2, the VOD furnace requirement to fireproof material

According to the smelt craft condition of VOD furnace, fireproof material should have following characteristics:

(1) is good in the stability below condition of high temperature vacuum.

(2) operates a condition to fall in high temperature, fireproof material should be had fight broken bits to permeate ability and erode ability.

(3) should have good heatproof shake sex.

3, the fireproof data that VOD furnace uses

Position of VOD slag line uses qualitative brick of magnesian chromic qualitative brick or magnesian calcium, sidewall pledges with magnesian chromium commonly or magnesian calcium pledges the brick, bottom also uses qualitative brick of magnesian chromic qualitative, tall aluminium (watch 1) ,

Function of VOD furnace firebrick:

VOD furnace is commonly used and fireproof material: Be united in wedlock directly

Magnesian chromic brick,

Recombine magnesium chromic brick,

Half recombine magnesium chromic brick,

Tall calcic magnesian dolomite brick,

Magnesian dolomite brick.