CN115109894B - Method for controlling splashing during desilication period of smelting stainless steel - Google Patents
Method for controlling splashing during desilication period of smelting stainless steel Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000003723 Smelting Methods 0.000 title claims abstract description 27
- 239000010935 stainless steel Substances 0.000 title claims abstract description 22
- 229910001220 stainless steel Inorganic materials 0.000 title claims abstract description 22
- 239000002893 slag Substances 0.000 claims abstract description 85
- 238000007664 blowing Methods 0.000 claims abstract description 70
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 62
- 239000001301 oxygen Substances 0.000 claims abstract description 62
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 62
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 33
- 239000010703 silicon Substances 0.000 claims abstract description 30
- 239000000463 material Substances 0.000 claims abstract description 25
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims abstract description 19
- 235000011941 Tilia x europaea Nutrition 0.000 claims abstract description 19
- 239000004571 lime Substances 0.000 claims abstract description 19
- 238000003756 stirring Methods 0.000 claims abstract description 12
- 238000005070 sampling Methods 0.000 claims abstract description 5
- 229910000831 Steel Inorganic materials 0.000 claims description 26
- 239000010959 steel Substances 0.000 claims description 26
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 25
- 238000004364 calculation method Methods 0.000 claims description 13
- 238000006243 chemical reaction Methods 0.000 claims description 11
- CSJDCSCTVDEHRN-UHFFFAOYSA-N methane;molecular oxygen Chemical compound C.O=O CSJDCSCTVDEHRN-UHFFFAOYSA-N 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 6
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 4
- 229910000423 chromium oxide Inorganic materials 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 abstract description 9
- 239000000956 alloy Substances 0.000 abstract description 9
- 230000003647 oxidation Effects 0.000 abstract description 8
- 238000007254 oxidation reaction Methods 0.000 abstract description 8
- 238000005261 decarburization Methods 0.000 abstract description 5
- 238000009628 steelmaking Methods 0.000 abstract description 2
- 229910052799 carbon Inorganic materials 0.000 description 10
- 239000011651 chromium Substances 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000006260 foam Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 208000028659 discharge Diseases 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 229910000599 Cr alloy Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229910002064 alloy oxide Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000000788 chromium alloy Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000010587 phase diagram Methods 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0087—Treatment of slags covering the steel bath, e.g. for separating slag from the molten metal
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Abstract
The invention relates to the field of steelmaking. A method for controlling splashing during desilication of smelting stainless steel comprises the following steps: (1) loading high-silicon premelt into an AOD furnace, and measuring temperature and sampling; (2) Calculating the addition amount of cold materials, the addition amount of lime and the oxygen blowing amount of oxygen according to the furnace charging condition; (3) starting to observe the flame at the furnace mouth when the oxygen blowing amount reaches 80-90%; (4) after stopping blowing, using bottom blowing stirring; (5) The furnace is rocked to 85-90 degrees, the low-alkalinity slag is poured into a slag pot, and normal smelting is started from 0-4 degrees. The method reduces the oxidation of the alloy while guaranteeing the desilication, guarantees the fluidity of slag by reasonably controlling the physicochemical properties of slag at the final point of the desilication, guarantees the successful pouring of low-alkalinity slag, and creates good conditions for the subsequent decarburization.
Description
Technical Field
The invention relates to the field of steelmaking, in particular to a method for controlling splashing in a desilication period of smelting stainless steel.
Background
At present, in order to further reduce the stainless steel smelting cost, the stainless steel smelting process is greatly developed. As new technology is developed and the addition amount of the AOD cold charge starts to become larger, the high-carbon high-silicon material becomes the main stream of stainless steel production. In the actual production process, the carbon and silicon content of the pre-solution is greatly increased, the silicon content in the pre-solution reaches 5 percent (mass percent) at most, and the carbon content is also increased to 2-5 percent (mass percent), so that an operation method for timely pouring out low-alkalinity slag at the end of desilication (the operation method is defined as the desilication period before the Si is greatly oxidized to the beginning of the severe carbon-oxygen reaction in the early stage of blowing high-silicon pre-melt) is developed for solving the problem of large slag content after the oxidation of silicon element. The silicon element brought by the premelt solution with high silicon content is oxidized preferentially to generate slag, the alkalinity of the slag is reduced along with the oxidation of silicon, the surface tension is increased, and the good fluidity and the air impermeability provide a foundation for the formation of foam slag; with the further progress of oxygen blowing, the silicon content in molten steel is reduced, and Cr in slag is reduced 2 O 3 The content is rapidly increased, the temperature is increased along with the rapid increase, the carbon-oxygen reaction is further aggravated, and a large amount of formed gas provides a dynamic condition for the foaming of the slag; along with itThe silicon oxide content in the slag is rapidly increased along with massive oxidation of silicon element, the slag content is rapidly increased, the slag layer in the furnace is thickened, the viscosity of the slag is increased, and a large amount of carbon monoxide gas generated by the carbon-oxygen reaction is more difficult to discharge, so that slag content conditions are provided for splashing. After the alkalinity, temperature, slag quantity and carbon-oxygen reaction conditions are all satisfied, a large amount of foam slag can be formed to flow out of a furnace mouth, accidents are caused by splashing, and meanwhile, a large amount of alloy oxides in the slag are lost along with splashing, so that the alloy cost is lost.
Slag alkalinity in the desilication period, bath temperature, slag quantity, carbon-oxygen reaction, oxygen blowing quantity control and silicon content control in the premelt are all important factors influencing splashing, and improper control is very easy to cause splashing.
Chinese patent CN 105525055B discloses a control method for splashing in a decarburization period of converter slag-less smelting, and aims at the problem that the mass fraction of Si in molten iron entering the converter is between 0.2 and 0.7 percent, the splashing in the decarburization period of the converter is controlled mainly by controlling the gun position of a top gun and the oxygen supply operation, and by adding auxiliary materials and controlling the alkalinity of slag, the effect of controlling the splashing is achieved, the applicability to stainless steel smelting is not strong, and meanwhile, the production problem that the silicon content of stainless steel is more than 1.0 percent of premelt can not be solved. Chinese patent CN 10877614B discloses a method for suppressing splashing in the earlier stage of converter smelting, which mainly controls splashing by controlling the lance position and oxygen pressure of the top lance in the earlier stage of blowing and increasing the bottom blowing stirring effect, but can only suppress splashing by operating the oxygen lance, but cannot reduce the slag amount, thereby fundamentally solving the problem of splashing. Chinese patent CN 105755199B discloses "anti-splash smelting control for smelting high silicon molten iron in a converter", in which, in the converter, desilication slag is poured out in the slag discharge stage, the gun position and oxygen supply strength of the top gun are controlled in the smelting stage, and the binary basicity of the final slag is controlled to achieve the purpose of controlling splash, but in order to ensure the fluidity of slag in slag pouring, sufficient metal oxidation of slag is required, a great amount of chromium element in premelted solution is unavoidable in the stainless steel production process, and a great amount of alloy is lost in slag pouring.
The applicant found in practical research that the above method for controlling the splashing can effectively control the splashing mainly for smelting the carbon steel in the converter, but forStainless steel with high alloy content is not applicable to smelting, the problem of metal oxide loss in stainless steel slag cannot be solved, and the problem of small AOD furnace capacity ratio cannot be avoided. AOD in the process of smelting stainless steel by using premelt with higher silicon content, the furnace volume ratio (0.52 m 3 And/t) is far smaller than a converter, the splashing cannot be well controlled by using the method, and a great amount of alloy loss along with slag is easily caused, so that a slag control method special for an AOD desilication period is needed to be found out, and the early-stage splashing of the AOD is controlled under the condition of ensuring that chromium alloy is not lost.
Disclosure of Invention
The invention aims to solve the problems and provides a method for controlling splashing during the desilication period of smelting stainless steel.
The purpose of the invention is realized in the following way: a method for controlling splashing during desilication of smelting stainless steel comprises the following steps: (1) loading high-silicon premelt into an AOD furnace, and measuring temperature and sampling; (2) According to the furnace charging condition, the cold charge addition amount, the lime addition amount and the oxygen blowing amount are calculated according to the following calculation formula: 1) The calculation formula of the cold charge addition amount is as follows: cold charge addition= (in-furnace silicon content-0.35%) x 31 Si content of 8+ early-stage materials ≡steel blending amount ≡31 ≡8; the Si content at the end point is controlled to be 0.2-0.5%, the blowing is 0.1%, the Si content is heated to 28-35 ℃, and the temperature is reduced by 7-11 ℃ per ton of cold material; 2) Lime is supplemented in the blowing desilication period, so that the binary alkalinity at the desilication end stage is controlled to be 1.3-1.5, and the calculation formula is as follows: lime addition= ((furnace silicon content-0.35%) ×steel addition+preliminary material Si content) ×2.14x1.4; the Si content of the end point is controlled to be 0.2-0.5%, and the binary alkalinity of the desilication end point is controlled to be 1.2-1.6; 3) The calculation formula of the oxygen blowing amount in the desilication period is as follows: oxygen blowing amount in desilication period= ((furnace silicon-0.35%) ×steel adding amount×0.8+Si content of earlier material×0.8)/(oxygen utilization rate); the content of Si at the end point is controlled to be 0.2-0.5%, and the oxygen utilization rate is 65-85%; the oxygen blowing amount is between 65 and 85 percent according to the different desilication utilization rates of the silicon and the carbon content in the furnace; (3) When the oxygen blowing amount reaches 80-90%, the flame at the furnace mouth is observed, when flame overflow occurs and a small amount of slag is splashed at the furnace mouth, the carbon-oxygen reaction is aggravated, the slag layer is foamed, and blowing is stopped at the moment; (4) After stopping blowing, using bottom blowing stirring, and reducing chromium oxide in slag by utilizing good fluidity of steel slag and Si remained in the molten steel; (5) The furnace is rocked to 85-90 degrees, the low-alkalinity slag is poured into a slag pot, and normal smelting is started from 0-4 degrees.
The oxygen supply intensity after the blowing is controlled to be 1.7-1.9 Nm < 3 >/(min/t), and the gun position is operated by adopting a low gun position.
And adding cooling cold materials into the molten pool in batches according to oxygen blowing amount and oxygen blowing time in the blowing process, wherein the feeding is uniform, and the temperature of the molten pool is ensured to be stable between 1450 and 1550 ℃.
Stirring with inert gas at stirring flow rate of 0.7-1.1Nm 3 And (2) stirring time is controlled to be 3-5 minutes.
The beneficial effects of the invention are as follows: the method reasonably controls the slag alkalinity, the bath temperature and the Si content at the desilication end point in the desilication period of stainless steel smelting, reasonably controls the oxygen blowing amount in the desilication period, and effectively controls the splashing in the desilication period of stainless steel smelting. The method reduces the oxidation of the alloy while guaranteeing the desilication, guarantees the fluidity of slag by reasonably controlling the physicochemical properties of slag at the final point of the desilication, guarantees the successful pouring of low-alkalinity slag, and creates good conditions for the subsequent decarburization.
Detailed Description
The method creatively proposes: the physical and chemical properties such as slag temperature, alkalinity and the like in the early stage of AOD converting are reasonably controlled, the carbon-oxygen reaction is controllable in the desilication period, the desilication oxygen utilization rate is improved, and a large amount of oxidation of alloy is avoided while desilication is carried out; the oxygen blowing amount is reasonably controlled, and the Si content in the premelt at the end of desilication is controlled while the desilication is fully performed; the temperature of a molten pool at the end of desilication and the alkalinity of slag are controlled within a reasonable range, so that the fluidity of slag at the end of desilication is ensured, and the subsequent slag pouring effect is ensured to be good.
The applicant passes through CaO-SiO on slag 2 -MgO-Cr 2 O 3 The quaternary phase diagram analysis shows that: the temperature of the molten pool should be controlled between 1480 and 1530 ℃, the physical and chemical properties of the slag are best, the physical and chemical properties of the slag are controlled in a green area, the good fluidity of the slag at the end of desilication can be well ensured, and the method is very beneficial to the reduction of metal oxides in the slag and the deslagging. Therefore, the slag basicity should be controlled to be 1.3-1.5, the Si content of the molten steel is controlled to be 0.3-0.4%, and the temperature is about 1500 ℃.
The oxidation-reduction reaction of the silicon element and the chromium element is as follows: cr (Cr) 2 O 3 +Si→Cr+SiO 2 When the theoretical calculation is carried out at 1500 ℃, the silicon content in molten steel is higher than 0.35%, and when the alkalinity in slag is 1.4, cr in slag is contained 2 O 3 The balance content is between 1.2-1.8%, at a cost acceptable level. Therefore, the Si content at the end of desilication is controlled to be 0.3-0.4% more reasonably.
The specific technical scheme of the invention is as follows:
1) And (5) loading the high-silicon premelt into an AOD furnace, and measuring the temperature and sampling.
2) According to the furnace charging condition, the cold charge addition amount, the lime addition amount and the oxygen blowing amount are calculated according to the following calculation formula: (1) the addition of the cold materials ensures the temperature balance in the desilication period, avoids the rapid temperature rise, causes severe carbon-oxygen reaction and splash, and has the following calculation formula: cold charge addition= (furnace silicon content-0.35%) ×31/8+earlier stage material Si content × 31/8, the Si content at the end point is controlled to be 0.35%; blowing to raise the temperature to 31 ℃ when the Si content is 0.1%; the temperature of each ton of cold material is reduced by 8 ℃. (2) Lime is supplemented in the blowing desilication period, so that the binary alkalinity at the desilication end stage is controlled to be 1.3-1.5, and the calculation formula is as follows: lime addition= ((furnace silicon content-0.35%) ×steel addition+earlier material Si content) ×2.14×1.4, terminal Si content controlled at 0.35%; the desilication end point binary alkalinity is controlled at 1.4. (3) The Si content in the premelt solution reaches the target value, and meanwhile, the excessive oxygen blowing amount is avoided, so that the Si content in the slag at the desilication end point is low, the chromium oxide content in the slag is high, and meanwhile, the excessive low Si content can cause severe carbon-oxygen reaction and cause splashing. The calculation formula of the oxygen blowing amount in the desilication period is as follows: oxygen blowing amount in desilication period= ((furnace silicon-0.35%) ×steel adding amount×0.8+ earlier material Si content×0.8)/(oxygen utilization rate), and terminal Si content is controlled at 0.35%; the oxygen utilization rate takes 65% -85%; the oxygen blowing amount fluctuates between 65% and 85% according to different desilication utilization rates of the silicon and carbon contents in the furnace, the oxygen utilization rate changes due to the change of the silicon and carbon contents in the furnace, and the desilication oxygen utilization rate is reduced due to high carbon content in the furnace and low silicon content.
3) When the oxygen blowing amount reaches 85%, the flame at the furnace mouth starts to be observed, when flame overflow occurs and a small amount of slag is splashed at the furnace mouth, the carbon-oxygen reaction starts to be aggravated, the slag layer starts to foam, and the blowing is stopped at the moment.
4) After stopping blowing, using bottom blowing stirring, and reducing chromium oxide in the slag by utilizing good fluidity of the steel slag and Si remained in the molten steel.
5) And (3) shaking the furnace to 85-90 degrees, pouring low-alkalinity slag into a slag pot, and starting normal smelting by shaking the furnace to-3 degrees.
The specific implementation steps are as follows:
1) And (3) adding the stainless steel premelt, measuring the temperature, sampling, and calculating the lime addition amount, the oxygen blowing amount and the cold charge addition amount according to the furnace charging condition.
2) The oxygen supply strength after the blowing is controlled to be 1.7-1.9 Nm 3 And/(min/t), the gun position is operated by adopting a low gun position.
3) Lime is added to slag after blowing is started, and the calculated value is controlled to be 20-30Kg/t.
4) And adding cooling cold materials into the molten pool in batches according to oxygen blowing amount and oxygen blowing time in the blowing process, wherein the feeding is uniform, and the temperature of the molten pool is ensured to be stable between 1450 and 1550 ℃.
5) The cold material addition follows the heavy material priority principle of high silicon high carbon material priority and high alloy component.
6) When oxygen is blown to the target value, the color of the flame is observed, and when the temperature is increased and a little slag splashes outwards, the oxygen blowing is stopped.
7) The side gun was stirred with an inert gas, and the stirring flow was controlled at 0.9Nm 3 And (2) stirring time is controlled to be 3-5 minutes.
8) And pouring low-alkalinity slag into a slag pot from the shaking furnace to 85-90 degrees until the slag cannot flow out, and starting normal smelting from the shaking furnace to-3 degrees.
Example 1
180 tons of AOD is used for producing SUS304 stainless steel, and an intermediate frequency furnace+AOD+LF+CC process is adopted.
1) Steel blending amount 108t, steel blending components: 3.53 percent of C, 3.15 percent of Si, 21.54 percent of Cr, 4.51 percent of Ni and 1408 ℃ of steel blending temperature.
2) After the steel is added, the furnace is rocked to-3 degrees to start converting, and the flow rate of the oxygen lance is 220Nm 3 The gun position is 1.9m, and the main gas of the side gun uses 80Nm of oxygen 3 Per min, nitrogen 20Nm 3 A/min; lime was added 5t after the start of converting.
3) After converting for 4min, the oxygen blowing amount reaches 1400Nm 3 And (5) adding the cold material 55t into the blowing stopping groove, and continuously adopting the parameters for blowing.
3) Blowing to 3000Nm 3 When oxygen is added, lime is added for 5t, high-level 30t cold charge is added at a constant speed, and the cold charge adding speed is controlled at 3t/min.
4) Converting to 4000 Nm 3 And when oxygen is added, lime is added for 4t, and the blowing parameters are unchanged to continue the blowing.
5) Oxygen blowing amount reaches 6500Nm 3 Stopping oxygen, stirring for 3.5min at the flow rate of the side gun of 100 Nm3/min, shaking the furnace, pouring slag, and measuring the temperature: 1501 ℃, sample components: 3.24 percent of C and 0.26 percent of Si meet the target requirement, the slag has good fluidity at the end of desilication, and Cr in the slag 2 O 3 The content is 2.27 percent, which meets the target requirement.
In the embodiment, the addition amount of the slag-forming lime is gradually increased by more oxygen blowing amount, the addition speed of the cold material is controlled, the temperature of a molten pool is stable, the desilication effect is good, and the splash phenomenon in the desilication period does not occur.
Example 2
180 tons of AOD are used for producing SUS316 stainless steel, and the process of (intermediate frequency furnace+electric furnace) +AOD+LF+CC is adopted.
1) Adding 180t of steel, and adding steel components: 2.499 percent of C, 1.19 percent of Si, 19.07 percent of Cr, 4.35 percent of Ni and 1552 ℃ of steel blending temperature.
2) After adding steel, the furnace is rocked to-3 degrees to start converting, and the oxygen lance flow is 180Nm 3 The gun position is 1.8m, the main gas of the side gun is 80Nm3/min of oxygen and 20Nm3/min of nitrogen; lime was added 5t after the start of converting.
3) After converting for 2min, the oxygen blowing amount reaches 800Nm 3 And starting to add high-level 20t cold material at a constant speed, wherein the adding speed of the cold material is controlled at 3t/min.
4) Blowing to 1500Nm 3 And when oxygen is added, lime is added for 2t, and the blowing parameters are unchanged to continue the blowing.
5) Oxygen blowing amount reaches 2500Nm 3 Stopping oxygen, stirring for 4.0min at the flow rate of the side gun of 100 Nm3/min, shaking the furnace, pouring slag, and measuring the temperature: 1552 DEG CSampling components: 2.15% of C and 0.31% of Si meet the target requirements, and the slag has good fluidity at the end of desilication and Cr in the slag 2 O 3 The content is 2.03 percent, which meets the target requirement.
In the embodiment, the addition amount of the slag-forming lime is gradually increased by more oxygen blowing amount, the addition speed of the cold material is controlled, the temperature of a molten pool is stable, the desilication effect is good, and the splash phenomenon in the desilication period does not occur.
The method reasonably controls the slag alkalinity, the bath temperature and the Si content at the desilication end point in the desilication period of stainless steel smelting, reasonably controls the oxygen blowing amount in the desilication period, and effectively controls the splashing in the desilication period of stainless steel smelting. The method reduces the oxidation of the alloy while guaranteeing the desilication, guarantees the fluidity of slag by reasonably controlling the physicochemical properties of slag at the final point of the desilication, guarantees the successful pouring of low-alkalinity slag, and creates good conditions for the subsequent decarburization.
The above embodiments are merely examples of the present invention, but the present invention is not limited to the above embodiments, and any changes or modifications within the scope of the present invention are intended to be included in the scope of the present invention.
Claims (1)
1. A method for controlling splashing during the desilication period of smelting stainless steel is characterized in that: the method comprises the following steps:
(1) Loading the high-silicon premelt into an AOD furnace, and measuring the temperature and sampling;
(2) According to the furnace charging condition, the cold charge addition amount, the lime addition amount and the oxygen blowing amount are calculated according to the following calculation formula:
1) The calculation formula of the cold charge addition amount is as follows: cold charge addition= (in-furnace silicon content-0.35%) x 31 Si content of 8+ early-stage materials ≡steel blending amount ≡31 ≡8; the Si content at the end point is controlled to be 0.2-0.5%, the blowing is 0.1%, the Si content is heated to 28-35 ℃, and the temperature is reduced by 7-11 ℃ per ton of cold material;
2) Lime is supplemented in the blowing desilication period, so that the binary alkalinity at the desilication end stage is controlled to be 1.3-1.5, and the calculation formula is as follows: lime addition= ((furnace silicon content-0.35%) ×steel addition+preliminary material Si content) ×2.14x1.4; the Si content of the end point is controlled to be 0.2-0.5%, and the binary alkalinity of the desilication end point is controlled to be 1.2-1.6; adding cooling cold materials into a molten pool in batches according to oxygen blowing amount and oxygen blowing time in the blowing process, wherein the feeding follows a uniform speed, and the temperature of the molten pool is ensured to be stable between 1450 and 1550 ℃;
3) The calculation formula of the oxygen blowing amount in the desilication period is as follows: oxygen blowing amount in desilication period= ((furnace silicon-0.35%) ×steel adding amount×0.8+Si content of earlier material×0.8)/(oxygen utilization rate); the content of Si at the end point is controlled to be 0.2-0.5%, and the oxygen utilization rate is 65-85%;
(3) When the oxygen blowing amount reaches 80-90%, the flame at the furnace mouth is observed, when flame overflow occurs and a small amount of slag is splashed at the furnace mouth, the carbon-oxygen reaction is aggravated, the slag layer is foamed, and blowing is stopped at the moment;
(4) After stopping blowing, using bottom blowing stirring, and reducing chromium oxide in slag by utilizing good fluidity of steel slag and Si remained in the molten steel;
(5) The furnace is rocked to 85-90 degrees, the low-alkalinity slag is poured into a slag pot, and normal smelting is started from 0-4 degrees.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210663229.8A CN115109894B (en) | 2022-06-13 | 2022-06-13 | Method for controlling splashing during desilication period of smelting stainless steel |
Applications Claiming Priority (1)
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102268593A (en) * | 2010-08-31 | 2011-12-07 | 振石集团东方特钢股份有限公司 | Production method of austenitic stainless steel |
| CN105132612A (en) * | 2014-05-29 | 2015-12-09 | 上海梅山钢铁股份有限公司 | Converter less slag smelting early stage deslagging control method |
| CN105506226A (en) * | 2014-09-26 | 2016-04-20 | 鞍钢股份有限公司 | Method for carrying out pre-desiliconization, pre-decarburization and pre-dephosphorization on molten iron in molten iron tank |
| CN105525055A (en) * | 2014-09-30 | 2016-04-27 | 上海梅山钢铁股份有限公司 | Method for controlling splashing in less slag smelting decarbonization period of converter |
| CN110117689A (en) * | 2019-06-11 | 2019-08-13 | 北京科技大学 | A method of based on high-silicon molten iron converter double slag process low phosphorus steel by smelting |
| CN110129517A (en) * | 2019-06-11 | 2019-08-16 | 北京科技大学 | The method that high-silicon molten iron improves desiliconization furnace dephosphorization rate is smelted based on converter duplex method |
-
2022
- 2022-06-13 CN CN202210663229.8A patent/CN115109894B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102268593A (en) * | 2010-08-31 | 2011-12-07 | 振石集团东方特钢股份有限公司 | Production method of austenitic stainless steel |
| CN105132612A (en) * | 2014-05-29 | 2015-12-09 | 上海梅山钢铁股份有限公司 | Converter less slag smelting early stage deslagging control method |
| CN105506226A (en) * | 2014-09-26 | 2016-04-20 | 鞍钢股份有限公司 | Method for carrying out pre-desiliconization, pre-decarburization and pre-dephosphorization on molten iron in molten iron tank |
| CN105525055A (en) * | 2014-09-30 | 2016-04-27 | 上海梅山钢铁股份有限公司 | Method for controlling splashing in less slag smelting decarbonization period of converter |
| CN110117689A (en) * | 2019-06-11 | 2019-08-13 | 北京科技大学 | A method of based on high-silicon molten iron converter double slag process low phosphorus steel by smelting |
| CN110129517A (en) * | 2019-06-11 | 2019-08-16 | 北京科技大学 | The method that high-silicon molten iron improves desiliconization furnace dephosphorization rate is smelted based on converter duplex method |
Non-Patent Citations (1)
| Title |
|---|
| 120t转炉双联法冶炼高硅铁水的工艺研究与生产实践;张春辉;《工程科技I辑》;第B023-26页 * |
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