CN100447271C - Method for smelting carbon dioxide corrosion resistant steel - Google Patents

Method for smelting carbon dioxide corrosion resistant steel Download PDF

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CN100447271C
CN100447271C CNB2005100262931A CN200510026293A CN100447271C CN 100447271 C CN100447271 C CN 100447271C CN B2005100262931 A CNB2005100262931 A CN B2005100262931A CN 200510026293 A CN200510026293 A CN 200510026293A CN 100447271 C CN100447271 C CN 100447271C
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steel
converter
temperature
content
corrosion resistant
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CN1873037A (en
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蒋晓放
许春雷
马志刚
章耿
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Baoshan Iron and Steel Co Ltd
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Baoshan Iron and Steel Co Ltd
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Abstract

The present invention relates to a method for smelting alloy steel, particularly to a method for smelting CO2 corrosion resistant steel. The present invention solves the technical problems of high production cost of an electric furnace, overoxidation of molten steel caused by two-time converting and two-time tapping of the existing converter, etc. The method for smelting the CO2 corrosion resistant steel is characterized in that the method comprises the following steps: dephosphorizing desulfurized molten iron by a converter; adding semi-molten steel to a decarburizing converter; raising the temperature of the converter for blowing, decarbonization and Cr preservation; adding high-carbon ferrochromium to smelt at a certain carbon content and temperature; continuously blowing oxygen and raising the temperature for decarbonization to make the Cr content in the molten steel reach over 8% and the P content less than 0.020%; then carrying out tapping and alloying; carrying out temperature elevation and alloy adjustment in a refining LF furnace; carrying out alloy composition fine-adjustment and degassing treatment in a refining RH furnace; finally carrying out casting in a mold to obtain a steel ingot. The present invention mainly uses the converter to produce the CO2 corrosion resistant steel L80-13Cr.

Description

A kind of smelting process of carbon dioxide corrosion resistant steel
Technical field:
The present invention relates to a kind of smelting process of steel alloy, particularly a kind of smelting process of carbon dioxide corrosion resistant steel.
Background technology:
Anti-CO 2Corrosion steel L80-13Cr is a kind of high-alloy stainless steel, and the main component of L80-13Cr is: [C]≤0.21%, [Si]≤0.55%, [Mn]≤0.65%, [P]≤0.020%, [S]≤0.008%, [Cr] 12～14%, [Al]≤0.030%.Since this steel grade chromium content height, and require phosphorus content low, therefore, this steel grade is smelted very difficulty, generally adopts electric furnace to produce the L80-13Cr stainless steel, because the electric furnace tonnage is less relatively, production cost is higher.Chinese patent 87100166 has been introduced a kind of high quality steel, especially the oxygen converter smelting technology method of the steel alloy that oxyphie alloying element such as chromium and manganese content are high.This invention belongs to steelmaking technical field by smelting technology being divided into two steps and carrying out making tapping temperature to remain within the satisfied scope at alloying element content during the melt aftertreatment after the higher and depletion temperature and can keeping low phosphorus content without difficulty.This inventive features is, in the first step smelting process, make the furnace charge nationality of forming by ferrous material and slag former help oxygen blast below formed basic slag, to carry out decarburization, dephosphorization and desulfurization also are heated to tapping temperature, the slag former such as the Wingdale of under the situation that reclaims converter slag, molten steel being emitted and in tapping process, carry out deoxidation and alloying and make molten steel and newly add, fluorite and alumina in case of necessity generate the high alkalinity slag, deoxidation reagent wherein, particularly the minimum amount of silicon is than reaching the necessary amount height of predetermined component, and determine the consumption of alloying additive according to existing melt heat storage capacity in the melting process, and in the second step smelting process, melt is injected oxygen converter and carries out after-blow, make the content of at least a reductor reach requirement and reach required outlet temperature, continue in case of necessity to add, make necessary alloying additive meet the final analysis result.This patent adopts twice tapping of twice blowing of converter, converter smelting needs decarburization, dephosphorization and desulfurization for the first time, when tapping, carry out alloying, converter smelting carries out after-blow for the second time, this method increases the possibility of Molten Steel over-oxidation, and causes the alloy partial oxidation when bessemerizing for the second time that adds when tapping for the first time easily, has reduced the recovery rate of alloy like this, and this patent do not have clear and definite temperature control when bessemerizing for the second time, more is unfavorable for the raising of yield of alloy; Simultaneously, this patent is not clear and definite to the chromium content in the steel, unclear related steel alloy composition range.Chinese patent 95111781.5 has been introduced a kind of method of utilizing the direct smelting stainless steel of top and bottom combined blown converter melting and reducing chrome ore, during smelting reduction, three layers of compound top of double flow duct rifle is blown into inert gas, a combustion oxygen flow, two combustion oxygen flows from bottom to top respectively to slag, one combustion oxygen flow, two combustion oxygen flow stirring heating slags, heat Cr materials efficiently, inert gas impacts the metal that is formed by the bottom blowing stirring of inert gas and gushes, make carbon in the molten drop of the metal side of swarming to the furnace wall disperse, fully mix with the carbon-bearing pellet that is enriched in this, promote the reduction of chromium.After melting and reducing finishes, adopt same top rifle in stove, to be blown into the decarburization oxygen of using inert gas dilution, high chromium hot melt is blown, the rare gas element of bottom blowing simultaneously violent stirring molten bath.This patent characteristic is: in the top and bottom combined blown converter with bottom blowing air port and top rifle, by carbon-bearing pellet in the adding stove and/or the chromium in the carbon source reducing chrome ore stone in the carbonaceous material, after obtaining high chromium hot melt, in same converter, saturated carbonaceous high chromium hot melt is carried out Decarburising and refining, finally make stainless steel.This is a kind of method of directly smelting stainless steel by chromium ore fusion reduction.This method can only be utilized the specialized stainless converter production of producing, and its equipment is different with conventional converter with the bottom blowing member, can't apply.
Summary of the invention:
The purpose of this invention is to provide the anti-CO of a kind of converter smelting 2The method of corrosion steel solves the technical problems such as Molten Steel over-oxidation of electric furnace production cost height and twice tapping of twice blowing of existing converter.Technical scheme of the present invention is: a kind of anti-CO 2The smelting process of corrosion steel, it is characterized in that may further comprise the steps: at first adopt converter dephosphorization behind the desulfurizing iron, then half steel water being blended into heats up after the decarburization converter bessemerizes and decarburization and cr yield, add the fusing of high-carbon ferrochrome when arriving certain carbon content and temperature, continue the heating by O2 blowing decarburization, when making the converter blow off in the molten steel [Cr] content reach more than 8%, [P] content goes out steel alloying then less than 0.020%; To refining LF stove heat up, the alloy adjustment; Carry out alloying constituent fine setting and degassing processing to refining RH again; Pour into steel ingot to die casting at last.The processing route that adopts: desulfurizing iron-converter dephosphorization-bessemerize+decarburization and cr yield-LF-RH-die casting.Concrete processing step is as follows:
The converter operation:
(6) desulfurizing iron arrives [S] content less than 0.005%;
(7) converter dephosphorization, control half steel water [P] content≤0.008%, 1300～1350 ℃ of blow off temperature;
(8) bessemerize, the ton steel control quantity of slag is less than 30kg, and the finishing blowing temperature is controlled at 1680～1720 ℃;
(9) bessemerize top, end back rifle and adopt low discharge oxygen supply, top rifle oxygen supply intensity 2.2～3.2m 3/ t.min, bottom blowing rare gas element, bottom blowing intensity 0.1～0.2m 3/ t.min utilizes the converter high hopper to criticize the throwing high carbon ferro-chrome, and every batch of steel per ton is thrown 10～16kg, and steel per ton is thrown 130～150kg altogether, and blow off molten steel [Cr] content is greater than 8%, and temperature is controlled at 1670～1700 ℃, and the blow off carbon content is controlled at 0.14～0.22%;
(10) converter ladle target [Cr] content 10～10.5%, adopt extra low carbon ferrochromium to increase [Cr], 1580 ℃ ± 10 ℃ of target ladle temperature.
Refining LF operation:
(4) add extra low carbon ferrochromium at the LF stove and adjust chromium composition to 12.7～13.0%, carry out slag making desulfurization and temperature adjustment simultaneously.
(5) other alloying constituent is adjusted to the target lower limit;
(6) target LF end ladle temperature is 1605 ± 5 ℃.
Refining RH operation:
(4) RH carries out alloy fine setting, the degassing and removes being mingled with;
(5) control vacuum tightness is less than 133.3Pa in RH handles, and target [H] requirement≤2ppm, last batch of alloy join and handle the concluding time assurance greater than 8min;
(6) RH handles whole target temperature: 1560 ± 5 ℃.
The die casting operation:
(3) ingot mould of die casting adopts up big and down small band heat-insulating shield hot top ingot mold;
(4) adopt the protection of feed trumpet blown inert gas in the casting process, adopt kish slag protection cast in the ingot mould.
Beneficial effect of the present invention:. adopt the present invention to make converter realize decarburization and cr yield in oxidation period, the rate of recovery of chromium reaches more than 87% in the stove, and the finished product phosphorus content successfully is controlled at below 0.020%.Other composition also satisfies fully produces the anti-CO of L80-13Cr 2The requirement of corrosion steel pipe materials has realized the purpose of converter steelmaking to the steel pipe feed.
Embodiment:
The anti-CO of embodiment 1-3:L80-13Cr 2Corrosion steel for steel pipes finished product composition sees Table 1.Converter finishes that the recovery rate of chromium reaches more than 87% in the high carbon ferro-chrome oxidation period, to refining finish the back all the chromium recovery rate of ferrochromes reach more than 91%.
Table 1 finished product composition unit: %
Numbering C Si Mn P S Cr Al H
Target component 0.18～0.21 0.35～0.55 0.45～0.65 ≤0.020 ≤0.008 12.5～14.0 0.010～0.030 ≤2ppm
Embodiment 1 0.1916 0.447 0.57 0.020 0.0012 12.93 0.023 1.2
Embodiment 2 0.1852 0.44 0.45 0.020 0.0022 13.03 0.023 1.1
Embodiment 3 0.1976 0.430 0.54 0.015 0.0059 12.71 0.026 1.6
Embodiment 1 concrete processing step following (300 tons):
The converter operation:
(1) desulfurizing iron, [S] content is 0.004% in the molten iron;
(2) converter dephosphorization, half steel water [P] content is 0.008%, 1325 ℃ of blow off temperature;
(3) bessemerize, the ton steel is controlled the quantity of slag less than 30kg, 1717 ℃ of finishing blowing temperature;
(4) bessemerize top, end back rifle and adopt low discharge oxygen supply, top rifle oxygen supply intensity 2.5m 3/ t.min, bottom blowing rare gas element, bottom blowing intensity 0.13m 3/ t.min utilizes the converter high hopper to criticize the throwing high carbon ferro-chrome, and every batch of steel per ton is thrown 12kg, and steel per ton is thrown 135kg altogether, and blow off molten steel [Cr] content is 8.1%, and temperature is controlled at 1671 ℃, and the blow off carbon content is controlled at 0.21%;
(5) adopt extra low carbon ferrochromium to increase [Cr], converter ladle [Cr] content 10.1%, 1572 ℃ of ladle temperature;
Refining LF operation:
(1) adds extra low carbon ferrochromium at the LF stove and adjust chromium composition to 12.9%, carry out slag making desulfurization and temperature adjustment simultaneously.
(2) other alloying constituent is adjusted to the target lower limit;
(3) LF end ladle temperature is 1608 ℃.
Refining RH operation:
(1) RH carries out alloy fine setting, the degassing and removes being mingled with;
(2) control vacuum tightness is less than 133.3Pa in RH handles, and target [H] requirement≤2ppm, last batch of alloy join and handle the concluding time is 8.5min;
(3) RH processing finishing temperature is 1561 ℃
The die casting operation:
(1) ingot mould of die casting adopts up big and down small band heat-insulating shield hot top ingot mold;
(2) adopt the protection of feed trumpet blown inert gas in the casting process, adopt kish slag protection cast in the ingot mould.
The implementing process of embodiment 2 is:
(1) desulfurizing iron, [S] content is 0.005% in the molten iron;
(2) converter dephosphorization, half steel water [P] content is 0.008%, 1350 ℃ of blow off temperature;
(3) bessemerize, the ton steel is controlled the quantity of slag less than 30kg, 1700 ℃ of finishing blowing temperature;
(4) bessemerize top, end back rifle and adopt low discharge oxygen supply, top rifle oxygen supply intensity 2.8m 3/ t.min, bottom blowing rare gas element, bottom blowing intensity 0.16m 3/ t.min utilizes the converter high hopper to criticize the throwing high carbon ferro-chrome, and every batch of steel per ton is thrown 14kg, and steel per ton is thrown 140kg altogether, and blow off molten steel [Cr] content is 8.3%, and temperature is controlled at 1690 ℃, and the blow off carbon content is controlled at 0.20%;
(5) adopt extra low carbon ferrochromium to increase [Cr], converter ladle [Cr] content 10.2%, 1580 ℃ of ladle temperature;
Refining LF operation:
(1) adds extra low carbon ferrochromium at the LF stove and adjust chromium composition to 12.9%, carry out slag making desulfurization and temperature adjustment simultaneously.All the other are identical with embodiment 1.
The implementing process of embodiment 3 is:
(1) desulfurizing iron, [S] content is 0.003% in the molten iron;
(2) converter dephosphorization, half steel water [P] content is 0.005%, 1311 ℃ of blow off temperature;
(3) bessemerize, the ton steel is controlled the quantity of slag less than 30kg, 1690 ℃ of finishing blowing temperature;
(4) bessemerize top, end back rifle and adopt low discharge oxygen supply, top rifle oxygen supply intensity 3.0m 3/ t.min, bottom blowing rare gas element, bottom blowing intensity 0.18m 3/ t.min utilizes the converter high hopper to criticize the throwing high carbon ferro-chrome, and every batch of steel per ton is thrown 15kg, and steel per ton is thrown 150kg altogether, blow off molten steel [Cr] content 8.7%, and temperature is controlled at 1700 ℃, and the blow off carbon content is controlled at 0.17%;
(5) adopt extra low carbon ferrochromium to increase [Cr], converter ladle [Cr] content 10.3%, 1582 ℃ of ladle temperature;
Refining LF operation:
(1) adds extra low carbon ferrochromium at the LF stove and adjust chromium composition to 12.7%, carry out slag making desulfurization and temperature adjustment simultaneously.
All the other are identical with embodiment 1.

Claims (5)

1, a kind of smelting process of carbon dioxide corrosion resistant steel, it is characterized in that may further comprise the steps: desulfurizing iron at first adopts converter dephosphorization to S content after 0.005%, control half steel water P content≤0.008%, 1300～1350 ℃ of blow off temperature, then half steel water being blended into heats up after the decarburization converter bessemerizes and decarburization and cr yield, bessemerize ton steel control quantity of slag less than 30kg, the finishing blowing temperature is controlled at 1680～1720 ℃, bessemerize and finish the oxygen supply of top, back rifle employing low discharge, top rifle oxygen supply intensity 2.2～3.2m 3/ t.min, bottom blowing rare gas element, bottom blowing intensity 0.1～0.2m 3/ t.min, utilize the converter high hopper to criticize the throwing high carbon ferro-chrome, every batch of steel per ton is thrown 10～16kg, steel per ton is thrown 130～150kg altogether, blow off molten steel [Cr] content is greater than 8%, and temperature is controlled at 1670～1700 ℃, and the blow off carbon content is controlled at 0.14～0.22%, [P] content goes out steel alloying then less than 0.020%; To refining LF stove heat up, the alloy adjustment; Carry out alloying constituent fine setting and degassing processing to refining RH again; Pour into steel ingot to die casting at last.
2, the smelting process of a kind of carbon dioxide corrosion resistant steel according to claim 1 is characterized in that converter ladle target [Cr] content 10～10.5%, adopts extra low carbon ferrochromium to increase [Cr], 1580 ± 10 ℃ of target ladle temperature.
3, the smelting process of a kind of carbon dioxide corrosion resistant steel according to claim 1, it is characterized in that LF stove refining procedure is: add extra low carbon ferrochromium at the LF stove and adjust chromium composition to 12.7～13.0%, carry out slag making desulfurization and temperature adjustment simultaneously, other alloying constituent is adjusted to the target lower limit, and it is 1605 ± 5 ℃ that target LF finishes the ladle temperature.
4, the smelting process of a kind of carbon dioxide corrosion resistant steel according to claim 1, it is characterized in that RH stove refining procedure is: RH carries out alloy fine setting, the degassing and removes being mingled with, control vacuum tightness is less than 133.3Pa in RH handles, target H requirement≤2ppm, the last batch of alloy joins handles the concluding time assurance greater than 8min, and RH handles whole target temperature: 1560 ± 5 ℃.
5, the smelting process of a kind of carbon dioxide corrosion resistant steel according to claim 1; it is characterized in that the die casting operation is: the ingot mould of die casting adopts up big and down small band heat-insulating shield hot top ingot mold; adopt the protection of feed trumpet blown inert gas in the casting process, adopt kish slag protection cast in the ingot mould.
CNB2005100262931A 2005-05-30 2005-05-30 Method for smelting carbon dioxide corrosion resistant steel Active CN100447271C (en)

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Publication number Priority date Publication date Assignee Title
CN100447271C (en) * 2005-05-30 2008-12-31 宝山钢铁股份有限公司 Method for smelting carbon dioxide corrosion resistant steel
CN105798577A (en) * 2016-05-23 2016-07-27 山东黄金矿业(沂南)有限公司 Disassembly and assembly maintenance device for hydraulic wheel shaft of mining equipment
CN106755709B (en) * 2016-11-25 2019-02-01 江苏省沙钢钢铁研究院有限公司 Chromium method is matched in a kind of converter of low-carbon steel alloy containing Cr
CN112859951B (en) * 2021-01-04 2021-08-31 北京科技大学 Blowing CO2Dynamic control method for stainless steel smelting process

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