EP2252712A1 - Novel additive for treating resulphurized steel - Google Patents
Novel additive for treating resulphurized steelInfo
- Publication number
- EP2252712A1 EP2252712A1 EP09721360A EP09721360A EP2252712A1 EP 2252712 A1 EP2252712 A1 EP 2252712A1 EP 09721360 A EP09721360 A EP 09721360A EP 09721360 A EP09721360 A EP 09721360A EP 2252712 A1 EP2252712 A1 EP 2252712A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- steel
- additive
- cored wire
- inclusions
- liquid steel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 112
- 239000010959 steel Substances 0.000 title claims abstract description 112
- 239000000654 additive Substances 0.000 title claims abstract description 36
- 230000000996 additive effect Effects 0.000 title claims abstract description 34
- 238000000034 method Methods 0.000 claims abstract description 37
- 239000007787 solid Substances 0.000 claims abstract description 36
- 239000000378 calcium silicate Substances 0.000 claims abstract description 26
- 229910052918 calcium silicate Inorganic materials 0.000 claims abstract description 26
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 claims abstract description 26
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 13
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000007788 liquid Substances 0.000 claims description 58
- 238000011282 treatment Methods 0.000 claims description 28
- 229910052717 sulfur Inorganic materials 0.000 claims description 26
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 25
- 239000011593 sulfur Substances 0.000 claims description 25
- 230000008569 process Effects 0.000 claims description 22
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 6
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 6
- 230000004907 flux Effects 0.000 claims description 6
- 239000004571 lime Substances 0.000 claims description 6
- 230000005587 bubbling Effects 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 229910044991 metal oxide Inorganic materials 0.000 claims description 5
- 150000004706 metal oxides Chemical class 0.000 claims description 5
- 238000007872 degassing Methods 0.000 claims description 4
- 229910004261 CaF 2 Inorganic materials 0.000 claims description 2
- 150000002222 fluorine compounds Chemical group 0.000 claims description 2
- 238000000265 homogenisation Methods 0.000 claims description 2
- 239000000377 silicon dioxide Substances 0.000 abstract description 3
- 239000000945 filler Substances 0.000 abstract 2
- 239000004411 aluminium Substances 0.000 abstract 1
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- 239000011575 calcium Substances 0.000 description 24
- 239000000203 mixture Substances 0.000 description 19
- 235000012241 calcium silicate Nutrition 0.000 description 17
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 15
- 229910004298 SiO 2 Inorganic materials 0.000 description 15
- 229910052791 calcium Inorganic materials 0.000 description 15
- 238000009749 continuous casting Methods 0.000 description 11
- 230000008018 melting Effects 0.000 description 11
- 238000002844 melting Methods 0.000 description 11
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 9
- 238000007792 addition Methods 0.000 description 9
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 9
- 238000006477 desulfuration reaction Methods 0.000 description 9
- 230000023556 desulfurization Effects 0.000 description 9
- 239000002893 slag Substances 0.000 description 9
- 238000005266 casting Methods 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 5
- 230000005496 eutectics Effects 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- AGVJBLHVMNHENQ-UHFFFAOYSA-N Calcium sulfide Chemical class [S-2].[Ca+2] AGVJBLHVMNHENQ-UHFFFAOYSA-N 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 229910001338 liquidmetal Inorganic materials 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- 150000004763 sulfides Chemical class 0.000 description 2
- 230000001131 transforming effect Effects 0.000 description 2
- 206010010144 Completed suicide Diseases 0.000 description 1
- 240000001398 Typha domingensis Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- 229910021346 calcium silicide Inorganic materials 0.000 description 1
- 230000001914 calming effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000010310 metallurgical process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000011265 semifinished product Substances 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 229910052566 spinel group Inorganic materials 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 238000011272 standard treatment Methods 0.000 description 1
- 230000008022 sublimation Effects 0.000 description 1
- 238000000859 sublimation Methods 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 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
- C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
-
- 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
Definitions
- the present invention is in the technical field of cored wires for the introduction of additive into a bath of liquid steel, of the type comprising a metal sheath surrounding said additive, intended to treat special steels called resulfurized and especially killed aluminum.
- the invention also relates to a process for manufacturing resulfided steels using the aforementioned cored wire.
- resulfided steels steels whose manufacturing process involves an addition of sulfur in the bath of liquid metal.
- So-called resulfided steels are shades whose development by the "continuous casting" is sometimes difficult to control and this, especially since the contents of S (sulfur) and Al (aluminum) are high. Indeed, the castability of these shades in continuous casting degrades when the contents of S and Al are high, which is the case typically for an S content greater than 0.25% by weight and an Al content greater than 0 , 03% by weight.
- the flowability of the steel is closely related to the presence in the steel of suspended solid particles (inclusions) as it passes through the continuous tundish.
- These solid particles may be oxides, such as alumina (Al 2 O 3 ), or sulphides (CaS), which easily cling to the refractory walls of the continuous casting elements (cattails, nozzles ...) forming deposits, which causes blockages.
- oxides such as alumina (Al 2 O 3 ), or sulphides (CaS), which easily cling to the refractory walls of the continuous casting elements (cattails, nozzles ...) forming deposits, which causes blockages.
- these solid particles degrade the quality of the semi-finished products and thus the end-use properties of the steels.
- the inclusions of solid oxides of the alumina (Al 2 O 3 ) or spinel (Al 2 O 3 - MgO) type are essentially formed during the deoxidation operation of the steel (so-called calming operation) or even during oxidation of the bath of liquid metal during the production process. These inclusions must be absolutely transformed into liquid inclusions by addition of calcium (treatment inclusive), generally in the form of cored wire that may contain pure CaSi or Ca. The calcium thus introduced into the steel combines with the solid inclusions to form new compounds of the type AI 2 O 3 - CaO or Al 2 O 3 - CaO - SiO 2 which are liquid at the casting temperature of the worked steel.
- WO 2005/078142 and especially WO-2006/000714 A2 disclose various solid inclusion processing methods of introducing a cored wire in a bath of liquid steel deep inside the pocket so as to prevent the additives contained in the cored wire are vaporized before reaching a sufficient depth and / or reacting on the surface with the slag.
- the additives in question include calcium-supporting materials for treating endogenous inclusions.
- FIG. 1 schematizes the conventional steelmaking process, which comprises the three major steps presented above:
- step 1 desulphurization of the steel (period that may require several ten minutes);
- step 2 inclusionary treatment
- step 3 resulfuration of the steel.
- the present invention proposes to simplify the metallurgical process for manufacturing so-called resulfurized steels (or high sulfur content), thus ensuring a productivity gain, while guaranteeing an equivalent level of quality and good flowability of the steels obtained.
- the invention relates, according to a first aspect, to a flux-cored wire for the introduction of additive into a bath of liquid steel, said flux-cored wire being of the type comprising a metal sheath surrounding said additive, and characterized in that than said additive comprises predominantly (at least 85% by weight) calcium silicate.
- Calcium silicate is derived from the reaction in given proportions of lime (CaO) with silica (SiO 2 ).
- Calcium silicate is usually described in the state of the art in the form of the following binary mixture: (CaO, SiO 2 ) in which the proportion by weight of lime (CaO) relative to that of silica (SiO 2 ) is adjusted especially according to the target melting temperature for the calcium silicate obtained.
- the flux-cored wire according to the invention comprises a mixture of oxides based on calcium silicate (CaO-SiO 2 ) advantageously making it possible to eliminate the above-mentioned step 1 of prior desulfurization (gain of several tens of minutes) and to avoid the addition of calcium (Ca) (in any form: CaSi or pure Ca), while ensuring an effective treatment of the solid steel bath's inclusionary solid population, compatible with continuous casting techniques.
- This cored wire containing the mixture of oxides based on CaO-SiO 2 makes it possible, when it is introduced into the molten steel, to modify the nature and the morphology of the inclusions of solid oxides present in the bath. liquid steel without risking the formation of harmful solid sulphides.
- calcium silicides (“calcium suicide") added in the inclusion treatments known from the state of the art, in particular from document WO-2005/078142, and the oxides of calcium and silicon which are the calcium silicates (CaO-SiO 2 ) according to the present invention.
- the flux-cored wire according to the invention makes it possible, when it is introduced into a bath of liquid steel, to transform the solid inclusions present in the liquid steel (essentially oxides such as AI 2 O 3 ) which are at the origin capping of continuous flows, in liquid inclusions - at the casting temperature of the worked steel - which flow easily.
- the inclusions of oxides formed can advantageously be charged with sulfur (S) during the solidification of the steel, but there is no formation of calcium sulphide (CaS), that is to say of solid inclusions at the casting temperature of the worked steel comprising sulfur (S).
- said additive comprises a lime content (CaO) varying between 31% and 44% by weight and a silica (SiO 2 ) content varying between 56% and 69% by weight.
- the proportions of lime and silica are determined so as to correspond to the values contained in the circular zone delimited in dashed lines around the eutectic point referenced E in FIGS. 2 and 3, representing the ternary diagram AI 2 O 3 - CaO - SiO 2 . These proportions are optimal so as to obtain a calcium silicate (CaO-SiO 2 ) having a melting temperature less than or equal to the working temperature of the treated liquid steel.
- Precise point E refers to the preferred lime and silica ratios in the binary mixture formed by calcium silicate.
- the invention relates to a method for manufacturing special steels called "resulfurized", said method comprising a step of introducing, into the bath of liquid steel, the cored wire of the invention.
- These steels have a sulfur content which ranges from 0.02% to more than 0.25% by weight.
- the method of the invention is directed to the manufacture of aluminum resulfided steels.
- the process according to the invention makes it possible to treat the solid inclusions, in particular aluminum oxide Al 2 O 3 , contained in baths of liquid steels intended for the production of steels with a high sulfur content, without it is necessary to proceed with the prior desulphurization of the steel, while guaranteeing a modification of the solid inclusions and the improvement of the flowability required by the modern continuous casting tools.
- the process according to the invention comprises a first step intended to obtain a liquid steel base, for example by melting scrap, a second deoxidation step, a third shading step, a fourth degassing step. , a fifth step of treatment of solid inclusions using a cored wire according to the invention.
- the second step is to deoxidize the liquid steel bath which contains a very high content of dissolved oxygen, incompatible with subsequent manufacturing processes.
- the dissolved oxygen is fixed in particular by adding aluminum in the liquid steel bath.
- This second step is commonly called “calmage”.
- Dissolved oxygen and aluminum will then combine to form solid inclusions of alumina (Al 2 O 3 ) that should be transformed into liquid inclusions by changing their chemical composition for the continuous casting step.
- the third step of shading is the final shading of the liquid steel, possibly the sulfur content.
- said process does not include a desulfurization step before the step of treating solid inclusions, in particular before the fifth step of treatment of solid inclusions.
- said method comprises a gentle bubbling step of homogenizing the liquid steel ladle after the fifth solid inclusions treatment step, preferably with the aid of a porous plug disposed at the bottom of the ladle. liquid steel.
- This step serves to homogenize the distribution of inclusions.
- the invention also relates to the use of the aforementioned flux-cored wire to improve the flowability of the resulfurized steel baths.
- the object of the present invention is to replace the known steel treatment, intended to control the flowability of a bath of liquid steel, in particular resulfurized steel, by treatment with the aid of a calcium silicate additive.
- a calcium silicate additive As preferred means of introducing said additive into the liquid metal bath is used the cored wire technique, known for its efficiency and simplicity.
- the cored wire for the introduction of additive into a bath of liquid steel is of the type comprising a metal sheath surrounding said additive.
- said additive essentially comprises calcium silicate capable of interacting with the solid inclusions present in the liquid steel (in particular aluminum oxides Al 2 O 3 ) and transforming them into inclusions. fluids that flow easily and thus prevent clogging of continuous flows.
- the additive intended to be introduced into the bath of liquid steel, by means of the cored wire according to the invention may further comprise a flux (such as fluorides), whose role is to lower the melting temperature of the additive contained in the flux-cored wire, so as to bring it to the liquid state as soon as it is introduced into the bath of liquid steel and to keep it in this state, since only a liquid composition based on calcium silicate can absorb the solid particles present in the steel bath.
- a flux such as fluorides
- the additive intended to be introduced into the bath of liquid steel, by means of the cored wire according to the invention may further comprise another metal oxide such as FeO, MnO or MgO.
- the proportion of these metal oxides in the additive is less than or equal to 2% by weight. This metal oxide has the function of lowering the melting temperature of said additive. Beyond 2% by weight of said additive, said additive tends to form solid inclusions at the casting temperature.
- the invention relates to a method for manufacturing special steels called "resulfurized", said method comprising a step of introducing, into the bath of liquid steel, the cored wire of the invention.
- the process of the invention comprises a metallurgical treatment intended to modify the nature and the morphology of the inclusions present in a bath of liquid steel (in particular solid inclusions), at a precise moment of the elaboration of resulfided steels.
- This metallurgical treatment consists in introducing into the bath of liquid steel the flux-cored wire according to the invention, comprising a calcium silicate additive capable of acting on the solid inclusions, in particular of alumina, by transforming them into liquid inclusions. thus improving the flowability of the treated steel.
- the oxide mixture contained in the cored wire according to the invention has the particularity of having a low melting point.
- the strictly binary CaO - SiO 2 mixture has a eutectic point at 1436 ° C (for 63% SiO 2 ). This melting point may be decreased if the mixture is combined with other constituents such as metal oxides (FeO, MnO, MgO) or fluxes, for example of the CaF 2 type.
- the working temperatures during the preparation of the liquid steel are much higher than the melting temperature of the oxide mixture contained in the cored wire. It follows that the flux-cored wire introduced into the liquid steel bath releases fine particles of liquid oxides.
- the composition of the desired inclusions is shown in the attached figure 2, which represents the ternary diagram AI 2 O 3 - CaO - SiO 2 (from [I]).
- E represents the eutectic point of the "binary alloy” CaO - SiO 2
- VE represents the composition of the desired inclusions after inclusionary treatment.
- the eutectic point E corresponds to the reversible transformation of a liquid phase into two distinct solid phases.
- the preferred binary mixture within the scope of the present invention comprises by weight from 56% to 69% of silica (SiO 2 ) and from 31% to 44% of lime (CaO).
- VE represents the lowest melting temperature (1172 ° C.) of a given ternary mixture Al 2 O 3 - CaO - SiO 2 , which is determined from the eutectic point E so that the inclusions having this composition have a melting temperature much lower than that of steel.
- the inclusions are liquid at the casting temperature. In the rest of the process, these inclusions will be able to decant and be in turn captured by the pocket slag. Small inclusions, not eliminated, will have no impact on the flowability or the final properties of the steel. This process has several advantages.
- the process according to the invention is particularly suitable for the treatment of solid inclusions present in steel baths comprising aluminum.
- the process according to the invention makes it possible to significantly reduce the elaboration time of such steels since the desulfurization step can be purely and simply suppressed. This saving of time translates directly in term of gain of productivity but also in term of gain of energy, in particular electrical, and matter.
- the desulfurization of the liquid steel indeed requires controlling the chemical composition of the slag (additions of lime, alumina, aluminum for example), to carry out an intense bubbling in the pocket (gas insufflation by the porous plug, in particular argon) to promote the chemical exchange between the liquid steel and the slag, and in parallel to heat the bath of liquid steel (significant consumption of electrical energy).
- the invention makes it possible to eliminate the injection of cored wires containing CaSi or pure Ca.
- FIGS. 4 and 5, hereinafter appended, illustrate the main steps of a process for treating an aluminum-killed resulfurized steel given by way of non-limiting example and as known from the state of the art. for Figure 4 and improved according to the present invention for Figure 5.
- the grade of the treated steel is the same for the two processes shown in Figures 4 and 5. It is a steel 29MnCr5 with a sulfur content between 0.020% and 0.040% by weight and an aluminum content of between 0.015% and 0.040% by weight.
- the process described in FIG. 4 comprises a first melting step E 1 of the steel to be treated, a second deoxidation (dehydration) step E 2 , a third desulfurization step E 3 , a fourth shading step of pocket furnace steel E 4 (with the exception of the sulfur content), a fifth degassing step E 5 , a sixth step of inclusion treatment E 6 using a cored wire containing a calcium-based additive (CaSi or pure Ca), a seventh step of sulfur shading E 7 , and finally an eighth continuous casting step E 8 of the treated steel.
- the third step of desulfurization E 3 consists of desulphurizing the liquid steel, in particular by chemical exchanges between the steel and the supernatant slag.
- This desulphurization step is complex to implement since it requires perfectly mastering the chemical composition of the slag to allow chemical exchanges with the liquid steel optimally for the sixth step E 6 relating to the inclusion treatment.
- the second E 2 desulfurization step requires a minimum of time, at least 20 minutes in most known manufacturing processes, in order to reduce the sulfur content for the sixth step E 6 subsequent treatment of inclusions.
- the sixth step E 6 of treatment inclusions is carried out using a cored wire of calcium silicate (CaSi), in this specific example based on an alloy comprising 30% calcium.
- the seventh step E 7 of sulfur shading for final shading according to the specifications occurs only after a minimum waiting time, at least 5 minutes, following the sixth step E 6 .
- This waiting period makes it possible to reduce the probability of the sulfur combining with the calcium injected via the cored wire and thus avoiding the formation of calcium sulphides (CaS) forming solid inclusions at the casting temperature of the treated steel. , therefore harmful for casting in continuous casting.
- the process according to the invention, as illustrated in FIG. 5, advantageously makes it possible to eliminate the third desulphurization step E 3 and the seventh final shaping step E 7 of the treated steel.
- the second step E 2 > of shading of the steel to be treated in the pocket furnace consists of the final shading of the steel to be treated according to the specifications, including the sulfur content.
- the sixth step E & of inclusions treatment is carried out using a cored wire according to the present invention, comprising in this specific example a mixture of calcium silicate (CaO-SiO 2 ) and manganese oxide (MnO ) in the following proportions by weight: SiO 2 : 65.2%; CaO: 33.7%; MnO: 1.1%.
- the outer diameter of said cored wire is of the order of 13.5 mm, the metal sheath has a thickness of about 0.35 mm and the cored wire has a linear density of the order of 227 g / m.
- the temperature of the steel bag to which the cored wire is injected is of the order of 1592 ° C.
- the quantity of cored wire injected is of the order of 250 g per ton of steel.
- a soft homogenization bubbling using a porous plug located at the bottom of the bag is carried out for 7 minutes.
- the steel ladle is then ready to be transferred to continuous casting.
- the flowability recorded at the eighth step E 8 ' is in accordance with the average level of that recorded in the context of a standard method known from the state of the art, such as that illustrated in FIG. 4.
- the The defect rate recorded in continuous casting is 4.5% for the process illustrated in FIG. 5 against an average level of 4.92% for the known process illustrated in FIG. 4.
- the oxygen content just before the fifth step E 5 > degassing is 22 ppm.
- the oxygen content measured in the tundish, when the pocket still contains 70 tonnes of steel, is 15 ppm.
- the process illustrated in FIG. 5 makes it possible to significantly reduce the elaboration time of such steels since the desulfurization step E 3 can be purely and simply suppressed.
- This saving of time translates directly in term of gain of productivity but also in term of gain of energy, in particular electrical, and matter.
- the desulphurization of liquid steel indeed requires to control the chemical composition of the slag (additions of lime, alumina, aluminum for example), to carry out an intense bubbling in the pocket (insufflation of gas by the porous plug - consumption argon) to promote the chemical exchange between the liquid steel and the slag, and in parallel to heat the bath of liquid steel (significant consumption of electrical energy).
- the process according to the invention makes it possible to reduce the consumption of sulfur to be added to the liquid steel in order to comply with the specifications and to suppress the addition of CaSi or pure Ca for the inclusion treatment.
- the size of the pocket is 105 tons and the final shade of the treated steel 29MnCr5 is as follows:
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0851372A FR2928153B1 (en) | 2008-03-03 | 2008-03-03 | NEW ADDITIVE FOR THE TREATMENT OF RESULTS STEELS |
PCT/FR2009/050341 WO2009115722A1 (en) | 2008-03-03 | 2009-03-03 | Novel additive for treating resulphurized steel |
Publications (2)
Publication Number | Publication Date |
---|---|
EP2252712A1 true EP2252712A1 (en) | 2010-11-24 |
EP2252712B1 EP2252712B1 (en) | 2017-11-29 |
Family
ID=39616586
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP09721360.7A Active EP2252712B1 (en) | 2008-03-03 | 2009-03-03 | Novel additive for treating resulphurized steel |
Country Status (6)
Country | Link |
---|---|
US (1) | US9023126B2 (en) |
EP (1) | EP2252712B1 (en) |
BR (1) | BRPI0908043A2 (en) |
ES (1) | ES2654921T3 (en) |
FR (1) | FR2928153B1 (en) |
WO (1) | WO2009115722A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3821998A1 (en) * | 2019-11-18 | 2021-05-19 | Shanghai University | Cored wire for reducing degree of superheat of molten steel and use method thereof |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8828117B2 (en) | 2010-07-29 | 2014-09-09 | Gregory L. Dressel | Composition and process for improved efficiency in steel making |
JP6848369B2 (en) | 2015-11-27 | 2021-03-24 | 日本製鉄株式会社 | Sulfur-added raw material to molten steel and manufacturing method of sulfur-added steel |
EP3540082A4 (en) * | 2016-11-10 | 2020-06-03 | Nippon Steel Corporation | Sulfur additive for molten steel, and method for manufacturing sulfur-added steel |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6037250A (en) * | 1983-08-10 | 1985-02-26 | Kawasaki Steel Corp | Mold additive for continuous casting of steel |
US5268141A (en) * | 1985-04-26 | 1993-12-07 | Mitsui Engineering And Ship Building Co., Ltd. | Iron based alloy having low contents of aluminum silicon, magnesium, calcium, oxygen, sulphur, and nitrogen |
TW424017B (en) * | 1998-12-08 | 2001-03-01 | Shinagawa Refractories Co | Molding powder for continuous casting of steel and method for continuous casting of steel |
FR2792234B1 (en) * | 1999-04-15 | 2001-06-01 | Lorraine Laminage | TREATMENT TO IMPROVE THE CASABILITY OF CALM STEEL WITH CONTINUOUS CAST ALUMINUM |
WO2005078142A1 (en) * | 2004-02-11 | 2005-08-25 | Tata Steel Limited | A cored wire injection process ih steel melts |
FR2871477B1 (en) * | 2004-06-10 | 2006-09-29 | Affival Sa Sa | WIRE FOURRE |
EP1715065A3 (en) * | 2005-04-20 | 2007-08-15 | Corus Staal BV | A cored-wire for injecting into a steel melt and process of treating a steel melt using said wire |
-
2008
- 2008-03-03 FR FR0851372A patent/FR2928153B1/en not_active Expired - Fee Related
-
2009
- 2009-03-03 US US12/920,521 patent/US9023126B2/en active Active
- 2009-03-03 EP EP09721360.7A patent/EP2252712B1/en active Active
- 2009-03-03 ES ES09721360.7T patent/ES2654921T3/en active Active
- 2009-03-03 BR BRPI0908043-0A patent/BRPI0908043A2/en not_active IP Right Cessation
- 2009-03-03 WO PCT/FR2009/050341 patent/WO2009115722A1/en active Application Filing
Non-Patent Citations (1)
Title |
---|
See references of WO2009115722A1 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3821998A1 (en) * | 2019-11-18 | 2021-05-19 | Shanghai University | Cored wire for reducing degree of superheat of molten steel and use method thereof |
Also Published As
Publication number | Publication date |
---|---|
US9023126B2 (en) | 2015-05-05 |
ES2654921T3 (en) | 2018-02-15 |
US20110017018A1 (en) | 2011-01-27 |
FR2928153B1 (en) | 2011-10-07 |
WO2009115722A1 (en) | 2009-09-24 |
EP2252712B1 (en) | 2017-11-29 |
FR2928153A1 (en) | 2009-09-04 |
BRPI0908043A2 (en) | 2015-08-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA2889124C (en) | Inoculant alloy for thick cast-iron parts | |
EP2252712B1 (en) | Novel additive for treating resulphurized steel | |
FR2809745A1 (en) | High cleanness steel production includes adding a deoxidizing agent to a ladle before pouring steel melt into the ladle or adding deoxidizing agent to the melt during pouring of the melt into the ladle | |
CA1226737A (en) | High machinability steels fabrication process | |
CA1262636A (en) | Pre-refining treatment of metals and alloys | |
CA2243048C (en) | Carbon steel or low alloy cast steel, with improved machinability, and the steel-making process involved | |
EP0342132A1 (en) | Process for the desulfurization of pig iron | |
EP1029089B1 (en) | Method for continuous smelting of solid metal products | |
EP2918688B1 (en) | Method of desulphurisation of liquid cast iron, and flux-cored wire for implementing same | |
CA2004294C (en) | Mild steel for bar turning and process | |
RU2139943C1 (en) | Method for making high quality steel | |
BE1003182A4 (en) | Method for producing steel for standard use | |
EP1507876B1 (en) | Metallurgical treatment method on a metal bath | |
WO2023139230A1 (en) | Process for upgrading metals contained in petrochemical catalysts | |
BE436791A (en) | ||
BE432657A (en) | ||
BE483792A (en) | ||
BE559193A (en) | ||
BE544356A (en) | ||
CH164262A (en) | Process for improving steels. | |
CH285853A (en) | Process for the manufacture of gray cast iron parts with high mechanical resistance and part obtained by this process. | |
BE466674A (en) | ||
CH323985A (en) | Process for the production of refined cast iron and cast iron product obtained by this process | |
CH226491A (en) | Process for manufacturing low carbon ferroalloys, and in particular ferro-chromium. | |
FR2574433A1 (en) | Process for producing a manganese steel in an electric arc furnace with basic packing, and manganese steel obtained by the said process |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20100830 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR |
|
AX | Request for extension of the european patent |
Extension state: AL BA RS |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: POULALION, ANDRE Inventor name: GERARDIN, SEBASTIEN |
|
17Q | First examination report despatched |
Effective date: 20110128 |
|
DAX | Request for extension of the european patent (deleted) | ||
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R079 Ref document number: 602009049612 Country of ref document: DE Free format text: PREVIOUS MAIN CLASS: C21C0007040000 Ipc: C21C0007000000 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: C21C 7/00 20060101AFI20170628BHEP Ipc: C21C 7/04 20060101ALI20170628BHEP |
|
INTG | Intention to grant announced |
Effective date: 20170718 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D Free format text: NOT ENGLISH |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 950456 Country of ref document: AT Kind code of ref document: T Effective date: 20171215 Ref country code: CH Ref legal event code: NV Representative=s name: ARNOLD AND SIEDSMA AG, CH |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D Free format text: LANGUAGE OF EP DOCUMENT: FRENCH |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602009049612 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: SE Ref legal event code: TRGR |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2654921 Country of ref document: ES Kind code of ref document: T3 Effective date: 20180215 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 10 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20171129 |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 950456 Country of ref document: AT Kind code of ref document: T Effective date: 20171129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180228 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180228 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180301 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602009049612 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20180830 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: MM4A |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180303 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180303 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: TR Payment date: 20190212 Year of fee payment: 14 Ref country code: GB Payment date: 20190320 Year of fee payment: 11 Ref country code: FI Payment date: 20190219 Year of fee payment: 11 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 20190315 Year of fee payment: 11 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 20190410 Year of fee payment: 11 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20090303 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20171129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180329 |
|
REG | Reference to a national code |
Ref country code: FI Ref legal event code: MAE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200303 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20200331 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200331 Ref country code: SE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200304 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200331 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200331 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20200303 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200303 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 20210726 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: ES Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200304 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20230209 Year of fee payment: 15 |
|
P01 | Opt-out of the competence of the unified patent court (upc) registered |
Effective date: 20230419 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20240307 Year of fee payment: 16 |