CN113718177A - Medium-carbon industrial ultra-pure iron and preparation method thereof - Google Patents
Medium-carbon industrial ultra-pure iron and preparation method thereof Download PDFInfo
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- CN113718177A CN113718177A CN202111121339.3A CN202111121339A CN113718177A CN 113718177 A CN113718177 A CN 113718177A CN 202111121339 A CN202111121339 A CN 202111121339A CN 113718177 A CN113718177 A CN 113718177A
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- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 273
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 133
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 53
- 238000002360 preparation method Methods 0.000 title claims abstract description 18
- 239000002893 slag Substances 0.000 claims abstract description 103
- 238000006477 desulfuration reaction Methods 0.000 claims abstract description 95
- 230000023556 desulfurization Effects 0.000 claims abstract description 95
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 33
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 27
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 25
- 238000003723 Smelting Methods 0.000 claims abstract description 22
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 20
- 238000004519 manufacturing process Methods 0.000 claims abstract description 20
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 20
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 20
- 150000002910 rare earth metals Chemical class 0.000 claims abstract description 19
- 238000009749 continuous casting Methods 0.000 claims abstract description 18
- 239000012535 impurity Substances 0.000 claims abstract description 17
- 238000005266 casting Methods 0.000 claims abstract description 16
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 15
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000011593 sulfur Substances 0.000 claims abstract description 12
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000011574 phosphorus Substances 0.000 claims abstract description 6
- 238000000034 method Methods 0.000 claims description 38
- 229910000831 Steel Inorganic materials 0.000 claims description 23
- 239000010959 steel Substances 0.000 claims description 23
- 238000007664 blowing Methods 0.000 claims description 19
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 18
- 238000007670 refining Methods 0.000 claims description 17
- 238000010079 rubber tapping Methods 0.000 claims description 15
- 239000002994 raw material Substances 0.000 claims description 13
- 239000003795 chemical substances by application Substances 0.000 claims description 10
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 9
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 9
- 239000004571 lime Substances 0.000 claims description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 8
- 229910052684 Cerium Inorganic materials 0.000 claims description 8
- 229910052779 Neodymium Inorganic materials 0.000 claims description 8
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 8
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 8
- 229910052746 lanthanum Inorganic materials 0.000 claims description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 7
- 239000002131 composite material Substances 0.000 claims description 6
- 239000003607 modifier Substances 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 6
- 230000004048 modification Effects 0.000 claims description 5
- 238000012986 modification Methods 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 5
- 229910052786 argon Inorganic materials 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 4
- 238000010907 mechanical stirring Methods 0.000 claims description 4
- 238000005728 strengthening Methods 0.000 claims description 4
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 3
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 239000013049 sediment Substances 0.000 claims description 2
- 229910045601 alloy Inorganic materials 0.000 abstract description 15
- 239000000956 alloy Substances 0.000 abstract description 15
- 229910000797 Ultra-high-strength steel Inorganic materials 0.000 abstract description 11
- 239000011572 manganese Substances 0.000 description 18
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 6
- 239000010703 silicon Substances 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 238000005261 decarburization Methods 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 229910001122 Mischmetal Inorganic materials 0.000 description 1
- VVTSZOCINPYFDP-UHFFFAOYSA-N [O].[Ar] Chemical compound [O].[Ar] VVTSZOCINPYFDP-UHFFFAOYSA-N 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 235000000396 iron Nutrition 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000000844 transformation Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- C21C7/0006—Adding metallic additives
-
- 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
- C21C7/0025—Adding carbon material
-
- 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
- C21C7/06—Deoxidising, e.g. killing
-
- 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
- C21C7/064—Dephosphorising; Desulfurising
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention discloses medium-carbon industrial ultra-pure iron and a preparation method thereof, belonging to the technical field of metallurgical production. Provides the medium-carbon industrial ultra-pure iron suitable for producing the high-quality medium-low alloy ultra-high strength steel and the preparation method thereof. The medium-carbon industrial ultra-pure iron is a continuous casting or casting blank containing the following components in parts by weight: 0.3-0.5 wt%, Si is less than or equal to 0.04 wt%, Mn is less than or equal to 0.03 wt%, S is less than 0.001 wt%, P is less than or equal to 0.0025 wt%, Al is less than or equal to 0.005 wt%, Ti is less than or equal to 0.003 wt%, RE:0.001-0.01 wt%, the balance Fe, and other impurities less than 0.001 wt%; the preparation method comprises the steps of KR molten iron pre-desulfurization, converter double-slag dephosphorization smelting and LF double-slag deep desulfurization, and finally continuous casting or casting is carried out to obtain the ultra-pure carbon industrial iron in the square billet or the round billet in parts by weight, wherein the sulfur content in KR pre-desulfurized raw molten iron is less than 0.02%, the phosphorus content is less than 0.012%, the LF double-slag deep desulfurization comprises two steps of pre-desulfurization and deep desulfurization, and the deep desulfurization is carried out by adopting an ultra-alkalinity environment which increases the fluidity of slag and has a pH value of 3.0-5.0 and matching with 1Kg/t of mixed rare earth to carry out deep desulfurization and deep deoxidation and denature impurities in the molten iron.
Description
Technical Field
The invention relates to ultra-pure iron, in particular to medium-carbon industrial ultra-pure iron, and belongs to the technical field of metallurgical production. The invention also relates to a preparation method of the medium-carbon industrial ultra-pure iron.
Background
Pure iron is an important raw material for producing magnetic materials, electrothermal alloys, precision alloys and special metal materials, and along with the increasing requirements on precision alloys and magnetic components, the purity requirements of sophisticated high-tech products are also increasing.
The raw materials of pure iron and industrial pure iron are produced by GB9971 and GB6983 in China, and the pure iron and the industrial pure iron are generally manufactured by a converter or a converter plus external refining. However, the purity is not high, the impurity elements of pure iron are high, the quality purity of the product is low, and particularly, carbon, sulfur and phosphorus are high, so that the product can only be used for manufacturing common parts. These pure irons are already unsuitable for the manufacture of high-end products, for the production of raw materials for medium-low alloy ultra-high strength steels with carbon contents of 0.30-0.50%, and even for sophisticated technologies and high-quality components.
At present, through patent search, Japan and America adopt an electrolysis method to manufacture high-purity industrial pure iron, the purity can reach 99.9, but the price is very high, the high-purity industrial pure iron is generally manufactured by a converter or an electric furnace and external refining, and the high-purity industrial pure iron is manufactured by an AOD (argon oxygen decarburization) or VOD (vacuum oxygen decarburization) furnace, has low sulfur and phosphorus and the like in China. But only two types of ultra-low carbon are less than 0.001 percent and low carbon is less than or equal to 0.3 percent, and medium-carbon industrial pure iron specially prepared for medium-low alloy ultra-high strength steel with the carbon content of 0.30 to 0.50 percent is not seen. With the progress of the external refining technology and the large-scale and intelligent control of the external refining equipment, the converter/electric furnace + external refining means are adopted to produce the pure iron, the pure iron can be classified and graded according to specific use requirements, and meanwhile, the refining and purifying process is further optimized. Therefore, aiming at medium and low alloy ultrahigh-strength steel with the carbon content of 0.30-0.50%, the production cost of carbon alloying in the smelting process is reduced, and the development of medium-carbon industrial ultra-pure iron is urgently needed to solve the problems.
At present, a lot of patents or articles exist in the aspects of purifying iron by converter/electric furnace + external refining at home, but no reference or reference technology exists on a preparation method of the medium-carbon industrial ultra-pure iron which can be used for producing 300M (40CrNi2Si2MoVA) of higher-quality medium-low alloy ultra-high strength steel aiming at the medium-carbon industrial ultra-pure iron produced by adopting molten iron pretreatment, converter + external refining.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: provides the medium-carbon industrial ultra-pure iron which is suitable for producing high-quality medium-low alloy ultra-high strength steel. The invention also provides a preparation method of the medium-carbon industrial ultra-pure iron.
The technical scheme adopted for solving the technical problems is as follows: the medium-carbon industrial ultra-pure iron is a continuous casting or casting blank comprising the following components in parts by weight,
the components in parts by weight are as follows: 0.3-0.5 wt%, Si is less than or equal to 0.04 wt%, Mn is less than or equal to 0.03 wt%, S is less than 0.001 wt%, P is less than or equal to 0.0025 wt%, Al is less than or equal to 0.005 wt%, Ti is less than or equal to 0.003 wt%, RE:0.001-0.01 wt%, the balance Fe, and other impurities less than 0.001 wt%,
wherein RE is rare earth elements mainly including Ce, La, Nd and Pr.
The preparation method comprises the steps of KR molten iron pre-desulfurization, converter double-slag dephosphorization smelting, LF double-slag deep desulfurization, and continuous casting or casting to obtain square billets or round billets,
wherein, the content of sulfur in the raw material molten iron of KR pre-desulfurization is less than 0.02 percent, the content of phosphorus is less than 0.012 percent,
the LF double-slag deep desulfurization comprises two steps of pre-desulfurization and deep desulfurization, wherein in the deep desulfurization, the super-alkalinity environment which increases the fluidity of slag and has the pH value of 3.0-5.0 is adopted to be matched with 1Kg/t of mixed rare earth for deep desulfurization and deep deoxidation, and the inclusion in molten iron is denatured,
and when square billets or round billets are obtained by continuous casting or casting, a full-protection casting mode is adopted.
Further, KR desulfurization in advance is desulfurized through mechanical stirring and slagging, the final molten iron stability control S is less than 0.002%, and after molten iron desulfurization treatment, the KR desulfurization in advance is completed by removing desulfurization slag.
The preferable mode of the scheme is that the converter double-slag dephosphorization smelting adopts a high-oxidizability and high-alkalinity large-slag-quantity environment, carries out low-temperature smelting, blows nitrogen gas at the bottom, stirs and is matched with Si and Mn residual elements in the oxygen-blown ferric oxide water; and (3) slagging is carried out again by the converter after dephosphorization, the P of molten iron at the end point is stably controlled to be less than 0.0025%, slag stopping and tapping are adopted in the tapping process, the slag discharging amount is reduced, and carbon blocks are added for deoxidation in the tapping deoxidation.
Furthermore, in the deep desulfurization process of the LF double slag, carbon powder is added to ensure that the content of C is 0.30-0.50 wt% in the pre-desulfurization stage; strengthening the deoxidation of the slag and the molten steel, and carrying out composite deoxidation treatment on the steel slag by using an aluminum-containing top slag modifier and an aluminum wire to ensure that FeO + MnO steel slag is less than or equal to 1.0%; high alkalinity operation, alkalinity control in the range of 5.0-7.0; lime is added in small batches and in multiple batches at the later stage in the desulfurization process, S is stably controlled to be less than or equal to 0.001%, and the desulfurization slag is removed.
The preferable mode of the scheme is that in the LF double-slag deep desulfurization process, slagging is carried out again in the deep desulfurization stage, the alkalinity is controlled within the range of 3.0-5.0, the good slag fluidity is kept, a slagging agent is added according to the slag fluidity condition to improve the fluidity, 1Kg/t of mischmetal is added into a bin to carry out deep desulfurization, deep deoxidation and modification of inclusions in molten iron, and the refining slag is allowed to adsorb large-particle deoxidized and desulfurized inclusions in steel for enough soft blowing time; controlling the stability of the molten iron at the end point to be less than 0.001%, and controlling the content of the end point C according to the use requirement of specific pure iron: 0.3-0.5 wt%.
Further, the mixed rare earth comprises the components of 30% of La, 48% of Ce, 18% of Nd and 3% of Pr.
The preferable mode of the proposal is that when the mixed rare earth is added for the weak blowing deoxidation, the flow rate of the argon blowing is controlled to be 15-25Nm3/h, and the time is controlled to be 30-40 min.
Further, the sulfur content in the raw material molten iron in KR pre-desulfurization is less than 0.02 percent; the slagging agent in the converter double-slag dephosphorization smelting and LF double-slag deep desulfurization process is high-efficiency active metallurgical lime with CaO content more than 90%.
The invention has the beneficial effects that: this application uses current molten iron as the basis through adopting KR molten iron predesulfurization, converter two slag method dephosphorization smelting, the two slag deep desulfurization of LF, and the production flow preparation that the square billet or round billet was obtained in last continuous casting or casting the well carbon industry ultra-pure iron C of part by weight component: 0.3-0.5 wt%, Si is less than or equal to 0.04 wt%, Mn is less than or equal to 0.03 wt%, S is less than 0.001 wt%, P is less than or equal to 0.0025 wt%, Al is less than or equal to 0.005 wt%, Ti is less than or equal to 0.003 wt%, and RE:0.001-0.01 wt%, the balance of Fe, and less than 0.001 wt% of other impurities, and RE in the medium carbon industrial ultra-pure iron is controlled to be rare earth elements mainly comprising Ce, La, Nd and Pr. Thus, the carbon content of the industrial pure iron produced by the preparation method provided by the application is strictly controlled, and the content of all impurities is strictly controlled, so that the industrial pure iron provided by the application is suitable for producing high-quality medium-low alloy ultrahigh-strength steel, the technical problem that the industrial pure iron is not suitable for manufacturing high-end products and is not suitable for producing raw material industrial pure iron for medium-low alloy ultrahigh-strength steel with the carbon content of 0.30-0.50% in the prior art is solved, and the production of advanced technology and high-quality parts by adopting the independently controllable industrial pure iron becomes possible.
Detailed Description
In order to solve the technical problems in the prior art, the invention provides the medium-carbon industrial ultra-pure iron suitable for producing the high-quality medium-low alloy ultra-high strength steel, and the preparation method for the medium-carbon industrial ultra-pure iron. The medium-carbon industrial ultra-pure iron is a continuous casting or casting blank containing the following components in parts by weight,
the components in parts by weight are as follows: 0.3-0.5 wt%, Si is less than or equal to 0.04 wt%, Mn is less than or equal to 0.03 wt%, S is less than 0.001 wt%, P is less than or equal to 0.0025 wt%, Al is less than or equal to 0.005 wt%, Ti is less than or equal to 0.003 wt%, and RE:0.001-0.01 wt%, the balance of Fe, and less than 0.001 wt% of other impurities, wherein RE is rare earth elements mainly including Ce, La, Nd and Pr. : the preparation method respectively adopts the production processes of KR molten iron pre-desulfurization, converter double-slag dephosphorization smelting, LF double-slag deep desulfurization, and finally continuous casting or casting to obtain square billets or round billets to prepare the medium-carbon industrial ultra-pure iron with the components in parts by weight,
wherein, the content of sulfur in the raw material molten iron of KR pre-desulfurization is less than 0.02 percent, the content of phosphorus is less than 0.012 percent,
the LF double-slag deep desulfurization comprises two steps of pre-desulfurization and deep desulfurization, wherein the deep desulfurization is carried out by adopting an ultra-alkalinity environment with the pH value of 3.0-5.0 for increasing the fluidity of slag and matching with 1Kg/t of mixed rare earth for carrying out deep desulfurization and deep deoxidation and denaturing inclusions in molten iron, and the full-protection pouring mode is adopted when square billets or round billets are obtained by continuous casting or casting. This application uses current molten iron as the basis through adopting KR molten iron predesulfurization, converter two slag method dephosphorization smelting, the two slag deep desulfurization of LF, and the production flow preparation that the square billet or round billet was obtained in last continuous casting or casting the well carbon industry ultra-pure iron C of part by weight component: 0.3-0.5 wt%, Si is less than or equal to 0.04 wt%, Mn is less than or equal to 0.03 wt%, S is less than 0.001 wt%, P is less than or equal to 0.0025 wt%, Al is less than or equal to 0.005 wt%, Ti is less than or equal to 0.003 wt%, and RE:0.001-0.01 wt%, the balance of Fe, and less than 0.001 wt% of other impurities, and RE in the medium carbon industrial ultra-pure iron is controlled to be rare earth elements mainly comprising Ce, La, Nd and Pr. Thus, the carbon content of the industrial pure iron produced by the preparation method provided by the application is strictly controlled, and the content of all impurities is strictly controlled, so that the industrial pure iron provided by the application is suitable for producing high-quality medium-low alloy ultrahigh-strength steel, the technical problem that the industrial pure iron is not suitable for manufacturing high-end products and is not suitable for producing raw material industrial pure iron for medium-low alloy ultrahigh-strength steel with the carbon content of 0.30-0.50% in the prior art is solved, and the production of advanced technology and high-quality parts by adopting the independently controllable industrial pure iron becomes possible.
In the above-mentioned embodiment, guarantee the preparation effect of well carbon industry super pure iron to obtain the more accurate well carbon industry super pure iron of ingredient content, KR desulfurization in advance pass through mechanical stirring + slagging scorification mode desulfurization, terminal point molten iron stable control S < 0.002%, treat the molten iron desulfurization treatment back, take off the desulfurization sediment again and accomplish KR desulfurization work in advance. The converter double-slag dephosphorization smelting adopts a high-oxidizability and high-alkalinity large-slag-quantity environment, carries out low-temperature smelting, blows nitrogen gas at the bottom, stirs, and is matched with Si and Mn residual elements in the oxygen-blown ferric oxide water; and (3) slagging is carried out again by the converter after dephosphorization, the P of molten iron at the end point is stably controlled to be less than 0.0025%, slag stopping and tapping are adopted in the tapping process, the slag discharging amount is reduced, and carbon blocks are added for deoxidation in the tapping deoxidation. Correspondingly, in the deep desulfurization process of the LF double slag, carbon powder is added to ensure that the content of C is 0.30-0.50 wt% in the pre-desulfurization stage; strengthening the deoxidation of the slag and the molten steel, and carrying out composite deoxidation treatment on the steel slag by using an aluminum-containing top slag modifier and an aluminum wire to ensure that FeO + MnO steel slag is less than or equal to 1.0%; high alkalinity operation, alkalinity control in the range of 5.0-7.0; lime is added in small batches and in multiple batches at the later stage in the desulfurization process, S is stably controlled to be less than or equal to 0.001%, and the desulfurization slag is removed. In the LF double-slag deep desulfurization process, slagging is carried out again in a deep desulfurization stage, the alkalinity is controlled within the range of 3.0-5.0, the fluidity of the slag is kept good, a slagging agent is added according to the fluidity condition of the slag to improve the fluidity, 1Kg/t of mixed rare earth is added through a stock bin to carry out deep desulfurization, deep deoxidation and impurity modification in molten iron, and the refining slag is allowed to adsorb large-particle deoxidized and desulfurized impurities in steel through enough soft blowing time; controlling the stability of the molten iron at the end point to be less than 0.001%, and controlling the content of the end point C according to the use requirement of specific pure iron: 0.3-0.5 wt%. Meanwhile, in order to control the components of the rare earth in the pure iron, the mixed rare earth comprises the components of 30% of La, 48% of Ce, 18% of Nd and 3% of Pr. And when the mixed rare earth is added for weak blowing deoxidation, the argon blowing flow is controlled to be 15-25Nm3/h, and the time is controlled to be 30-40 min. And controlling the raw materials in KR pre-desulfurization, namely the sulfur content in the raw material molten iron is less than 0.02 percent; the slagging agent in the converter double-slag dephosphorization smelting and LF double-slag deep desulfurization process is high-efficiency active metallurgical lime with CaO content more than 90%.
In summary, compared with the prior art, the preparation method provided by the application also has the following beneficial effects: the KR molten iron pre-desulfurization can reduce the S of the molten iron fed into the furnace to a certain level; the converter double-slag method adopts oxidizing slag to remove residual elements such as P, Si, Mn and the like to the maximum extent; the carbon block is adopted for deoxidation after converter tapping, so that deoxidization by adopting deoxidants such as aluminum, silicon and manganese is avoided, and the content of aluminum, silicon and manganese in molten iron is avoided being increased; the medium carbon content in the molten iron is kept, and the oxidizing amount of the molten iron and slag is controlled to be beneficial to LF deep removal of S by carrying out composite deoxidation treatment on the steel slag by using an aluminum-containing top slag modifier and an aluminum wire; trace mixed rare earth is added in the last stage of LF, so that O, S and inclusions in modified molten iron can be effectively removed; and soft blowing is carried out for a long enough time in the last stage of LF, so that the refining slag can be ensured to adsorb large-particle rare earth deoxidation and desulfurization impurities in steel.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
The invention aims to solve the technical problem that pure iron is classified and graded according to specific use requirements of the pure iron, and meanwhile, the utilization of a pure iron refining and purifying process is further optimized by utilizing the large-scale and intelligent control of external refining equipment.
The invention aims to provide a method for producing medium-carbon industrial ultrapure iron, which adopts the processes of KR molten iron pre-desulfurization → converter double-slag dephosphorization → LF double-slag deep desulfurization → square billet or round billet continuous casting.
1) KR molten iron is desulfurized in advance by adopting molten iron with S less than 0.02 percent, KR is desulfurized in a mechanical stirring and slagging mode, and the KR molten iron has good thermodynamic and kinetic conditions of desulfurization, and the KR molten iron is stably controlled by S less than 0.002 percent at the end point. And after the molten iron is desulfurized, removing desulfurized slag.
2) The converter smelting adopts a double-slag dephosphorization method, which is favorable for the dynamic and thermodynamic conditions of P removal: high oxidizing property and high alkalinity, low-temperature smelting, bottom blowing nitrogen and stirring. Excess oxygen blowing is adopted to oxidize residual elements such as Si, Mn and the like in the molten iron as much as possible, the converter is subjected to slagging again after dephosphorization, the P of the molten iron is stably controlled to be less than 0.0025% at the end point, slag stopping and tapping are adopted in the tapping process, the slag discharging amount is reduced, carbon blocks are added for deoxidation in the tapping deoxidation, and deoxidizing agents such as aluminum, silicon, manganese and the like cannot be used for deoxidation, so that the content of aluminum, silicon and manganese in the molten iron is prevented from being increased.
3) In the stage of LF double-slag deep desulfurization and pre-desulfurization, carbon powder is added to ensure that the content of C is 0.30-0.50 wt%; strengthening the deoxidation of the slag and the molten steel, and carrying out composite deoxidation treatment on the steel slag by using an aluminum-containing top slag modifier and an aluminum wire to ensure that the steel slag (FeO + MnO) is less than or equal to 1.0 percent; high alkalinity operation, alkalinity control in the range of 5.0-7.0; lime is added in small batches and in multiple batches at the later stage in the desulfurization process, S is stably controlled to be less than or equal to 0.001%, and desulfurization slag is removed; and (3) a deep desulfurization stage: slagging is carried out again, the alkalinity is controlled within the range of 3.0-5.0, the fluidity of the slag is kept good, a slagging agent is added according to the fluidity condition of the slag to improve the fluidity, 1Kg/t of mixed rare earth (the main components of which are 30 percent of La, 48 percent of Ce, 18 percent of Nd and 3 percent of Pr, and other associated rare earth elements) is added through a storage bin to carry out deep desulfurization, deep deoxidation and the modification of inclusions in molten iron, and the refining slag is allowed to adsorb large-particle deoxidized and desulfurized inclusions in steel through enough soft blowing time. Controlling the stability of the molten iron at the end point to be less than 0.001%, and controlling the content of the end point C according to the use requirement of specific pure iron: 0.3-0.5 wt%. And transferring to a continuous casting process.
4) And (3) adopting a full-protection pouring mode to carry out continuous casting, and selecting square billets or round billets.
In the step 1), S in the blast furnace molten iron is less than 0.01 wt% as a preferred embodiment.
And 2) selecting high-efficiency active metallurgical lime with low sulfur content and CaO content of more than 90% for slagging in the step 3).
In the step 2),3), carbon blocks with low impurity content, especially low S content, can be selected for recarburization as a preferred embodiment.
In the step 2), the converter and LF smelting in the step 3) is a conventional smelting and secondary refining process, so that Mn and Si in molten iron can be effectively removed, and the molten iron meets the requirements of the component content standard of the low-carbon industrial ultra-pure iron, and the description is omitted in the invention.
The sufficient soft blowing time in the step 3) is as follows: and when the mixed rare earth is added for weak blowing deoxidation, controlling the flow of argon blowing at 15-25Nm3/h and controlling the time at 30-40 min.
The invention is suitable for large-scale production, the production cost is low, the efficiency is high, the industrial pure iron produced by adopting the technical scheme of the invention comprises the following components: c: 0.3 to 0.5 weight percent of Si, less than or equal to 0.04 weight percent of Mn, less than or equal to 0.03 weight percent of S, less than or equal to 0.001 weight percent of P, less than or equal to 0.0025 weight percent of Al, less than or equal to 0.005 weight percent of Ti, 0.001 to 0.01 weight percent of RE, RE is rare earth elements mainly including Ce, La, Nd and Pr, other impurities are less than 0.001 weight percent, and the balance is Fe. The percentages are mass percentages.
The present invention will be described in detail with reference to specific examples, but the present invention is not limited thereto.
The method for producing the medium-carbon industrial ultrapure iron adopts the processes of KR molten iron pre-desulfurization → converter double-slag dephosphorization → LF double-slag deep desulfurization → square billet or round billet continuous casting.
The KR molten iron pre-desulfurization adopts molten iron raw materials with S less than 0.02 percent and P less than 0.012 percent, and the molten iron with S less than 0.01 percent is allowed to be preferred in the case of the KR molten iron pre-desulfurization. And (4) after the desulfurized slag is removed, the molten iron enters the converter, and the sulfur content S of the molten iron fed into the converter is required to be less than 0.002%.
Converter smelting adopts a double-slag method for dephosphorization, oxygen blowing, high oxidizability, high alkalinity, large slag amount, low-temperature smelting and nitrogen bottom blowing stirring to remove residual elements such as P, Si, Mn and the like. And (4) slagging is carried out again on the converter after dephosphorization, and the P is stably controlled to be less than 0.0025% at the end point. And (3) stopping slag and tapping, reducing the slag amount, and deoxidizing by adding a carbon block without deoxidizing agents such as aluminum, silicon and manganese in the molten iron in the tapping deoxidization process so as to avoid increasing the contents of aluminum, silicon and manganese in the molten iron.
In the LF double-slag deep desulfurization and pre-desulfurization stage, carbon powder is added to ensure that the content of C is 0.30-0.50 wt%, the deoxidation of slag and molten steel is strengthened, and the composite deoxidation treatment is carried out on the steel slag by using an aluminum-containing top slag modifier and an aluminum wire to ensure that the steel slag (FeO + MnO) is less than or equal to 1.0%; high alkalinity operation, alkalinity control in the range of 5.0-7.0; lime is added in small batches and in multiple batches at the later stage in the desulfurization process, S is stably controlled to be less than or equal to 0.001%, and desulfurization slag is removed; and (3) a deep desulfurization stage: slagging is carried out again, the alkalinity is controlled within the range of 3.0-5.0, the fluidity of the slag is kept good, a slagging agent is added according to the fluidity condition of the slag to improve the fluidity, 1Kg/t of mixed rare earth (the main components of which are 30 percent of La, 48 percent of Ce, 18 percent of Nd and 3 percent of Pr, and the rest is other associated rare earth elements) is added through a storage bin to carry out deep desulfurization, deep deoxidation and the modification of inclusions in molten iron, and the refining slag is allowed to adsorb large-particle deoxidized and desulfurized inclusions in steel through enough soft blowing time. Controlling the stability of the molten iron at the end point to be less than 0.001%, and controlling the content of the end point C according to the use requirement of specific pure iron: 0.3-0.5 wt%. And transferring to a continuous casting process.
And (3) continuously casting by adopting a full-protection pouring mode, wherein square billets or round billets can be selected, 200mm square billets can be selected in 1-3 cases, and 240mm round billets can be selected in 4-5 cases.
TABLE 1 content (wt%) of ultra-pure iron component in carbon industry in examples 1 to 5
| C | Si | Mn | S | P | Al | Ti | RE | |
| Require that | 0.3-0.5 | ≤0.04 | ≤0.03 | ≤0.001 | ≤0.0025 | ≤0.005 | ≤0.003 | 0.001-0.01 |
| 1 | 0.36 | 0.030 | 0.022 | 0.0006 | 0.0024 | 0.003 | 0.0020 | 0.004 |
| 2 | 0.38 | 0.030 | 0.021 | 0.0008 | 0.0019 | 0.004 | 0.0017 | 0.003 |
| 3 | 0.37 | 0.028 | 0.022 | 0.0008 | 0.0017 | 0.003 | 0.0015 | 0.002 |
| 4 | 0.41 | 0.029 | 0.023 | 0.0007 | 0.0015 | 0.002 | 0.0018 | 0.004 |
| 5 | 0.41 | 0.025 | 0.020 | 0.0007 | 0.0020 | 0.0025 | 0.0010 | 0.007 |
As can be seen from Table 1, the contents of the elements in examples 1-5 all meet the technical requirements, particularly, the sulfur content can be controlled to be 0.0008% or less, and the rare earth content ranges from 0.005 to 0.012%.
The medium-carbon industrial ultra-pure iron prepared by the technical scheme of the invention can be applied to producing high-quality medium-low alloy ultra-high strength steel 300M (40CrNi2Si2 MoVA).
In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.
Claims (9)
1. A medium carbon industrial ultra-pure iron is characterized in that: the medium-carbon industrial ultra-pure iron is a continuous casting or casting blank containing the following components in parts by weight,
the components in parts by weight are as follows: 0.3-0.5 wt%, Si is less than or equal to 0.04 wt%, Mn is less than or equal to 0.03 wt%, S is less than 0.001 wt%, P is less than or equal to 0.0025 wt%, Al is less than or equal to 0.005 wt%, Ti is less than or equal to 0.003 wt%, and RE:0.001-0.01 wt%, the balance Fe, and other impurities less than 0.001 wt%,
wherein RE is rare earth elements mainly including Ce, La, Nd and Pr.
2. A method for producing the medium-carbon industrial ultra-pure iron according to claim 1, characterized in that: the preparation method respectively adopts the production processes of KR molten iron pre-desulfurization, converter double-slag dephosphorization smelting, LF double-slag deep desulfurization, and finally continuous casting or casting to obtain square billets or round billets to prepare the medium-carbon industrial ultra-pure iron with the components in parts by weight,
wherein, the content of sulfur in the raw material molten iron of KR pre-desulfurization is less than 0.02 percent, the content of phosphorus is less than 0.012 percent,
the LF double-slag deep desulfurization comprises two steps of pre-desulfurization and deep desulfurization, wherein in the deep desulfurization, the super-alkalinity environment which increases the fluidity of slag and has the pH value of 3.0-5.0 is adopted to be matched with 1Kg/t of mixed rare earth for deep desulfurization and deep deoxidation, and the inclusion in molten iron is denatured,
and when square billets or round billets are obtained by continuous casting or casting, a full-protection casting mode is adopted.
3. The method of claim 2, wherein: KR desulfurization in advance through mechanical stirring + slagging-off mode desulfurization, terminal molten iron stable control S is less than 0.002%, treat the molten iron desulfurization after-treatment, take off the desulfurization sediment again and accomplish KR desulfurization work in advance.
4. The method of claim 2, wherein: the converter double-slag dephosphorization smelting adopts a high-oxidizability and high-alkalinity large-slag-quantity environment, carries out low-temperature smelting, blows nitrogen gas at the bottom, stirs, and is matched with Si and Mn residual elements in the oxygen-blown ferric oxide water; and (3) slagging is carried out again by the converter after dephosphorization, the P of molten iron at the end point is stably controlled to be less than 0.0025%, slag stopping and tapping are adopted in the tapping process, the slag discharging amount is reduced, and carbon blocks are added for deoxidation in the tapping deoxidation.
5. The method of claim 2, wherein: in the deep desulfurization process of the LF double slag, carbon powder is added to ensure that the content of C is 0.30-0.50 wt% in the pre-desulfurization stage; strengthening the deoxidation of the slag and the molten steel, and carrying out composite deoxidation treatment on the steel slag by using an aluminum-containing top slag modifier and an aluminum wire to ensure that FeO + MnO steel slag is less than or equal to 1.0%; high alkalinity operation, alkalinity control in the range of 5.0-7.0; lime is added in small batches and in multiple batches at the later stage in the desulfurization process, S is stably controlled to be less than or equal to 0.001%, and the desulfurization slag is removed.
6. The method of claim 5, wherein: in the LF double-slag deep desulfurization process, slagging is carried out again in a deep desulfurization stage, the alkalinity is controlled within the range of 3.0-5.0, the fluidity of the slag is kept good, a slagging agent is added according to the fluidity condition of the slag to improve the fluidity, 1Kg/t of mixed rare earth is added through a stock bin to carry out deep desulfurization, deep deoxidation and impurity modification in molten iron, and the refining slag is allowed to adsorb large-particle deoxidized and desulfurized impurities in steel through enough soft blowing time; controlling the stability of the molten iron at the end point to be less than 0.001%, and controlling the content of the end point C according to the use requirement of specific pure iron: 0.3-0.5 wt%.
7. The production method according to any one of claims 2 to 6, characterized in that: the mixed rare earth comprises the components of 30% of La, 48% of Ce, 18% of Nd and 3% of Pr.
8. The method of claim 7, wherein: and when the mixed rare earth is added for weak blowing deoxidation, controlling the flow of argon blowing at 15-25Nm3/h and controlling the time at 30-40 min.
9. The method of claim 8, wherein: the sulfur content in the raw material molten iron in the KR pre-desulfurization is less than 0.02 percent; the slagging agent in the converter double-slag dephosphorization smelting and LF double-slag deep desulfurization process is high-efficiency active metallurgical lime with CaO content more than 90%.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB315444A (en) * | 1928-02-14 | 1929-07-15 | Leo Frederick Reinartz | Process of making commercially pure iron alloys |
| CN104630418A (en) * | 2015-01-15 | 2015-05-20 | 南京钢铁股份有限公司 | High-cleanliness pipeline steel smelting process |
| CN105603312A (en) * | 2015-12-22 | 2016-05-25 | 大冶特殊钢股份有限公司 | Manufacturing method of ultra-purity industrial pure iron |
| CN109797266A (en) * | 2019-01-14 | 2019-05-24 | 包头钢铁（集团）有限责任公司 | A kind of production method producing ingot iron using the high ferrous manganese ore of high phosphorus as raw material |
| CN110629118A (en) * | 2019-10-29 | 2019-12-31 | 成都先进金属材料产业技术研究院有限公司 | Medium-low carbon industrial ultra-pure iron and production method thereof |
| CN110747395A (en) * | 2019-10-29 | 2020-02-04 | 成都先进金属材料产业技术研究院有限公司 | Industrial ultra-pure iron and production method thereof |
-
2021
- 2021-09-24 CN CN202111121339.3A patent/CN113718177A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB315444A (en) * | 1928-02-14 | 1929-07-15 | Leo Frederick Reinartz | Process of making commercially pure iron alloys |
| CN104630418A (en) * | 2015-01-15 | 2015-05-20 | 南京钢铁股份有限公司 | High-cleanliness pipeline steel smelting process |
| CN105603312A (en) * | 2015-12-22 | 2016-05-25 | 大冶特殊钢股份有限公司 | Manufacturing method of ultra-purity industrial pure iron |
| CN109797266A (en) * | 2019-01-14 | 2019-05-24 | 包头钢铁（集团）有限责任公司 | A kind of production method producing ingot iron using the high ferrous manganese ore of high phosphorus as raw material |
| CN110629118A (en) * | 2019-10-29 | 2019-12-31 | 成都先进金属材料产业技术研究院有限公司 | Medium-low carbon industrial ultra-pure iron and production method thereof |
| CN110747395A (en) * | 2019-10-29 | 2020-02-04 | 成都先进金属材料产业技术研究院有限公司 | Industrial ultra-pure iron and production method thereof |
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